Here is the meaning of “drooped” in clear English + 中文解释：

drooped — meaning

1. to hang down; to bend downward because of tiredness, weakness, or weight

English: When something (like a flower, branch, or body part) hangs down loosely because it has no strength. 中文： 下垂、垂落；因为疲累、虚弱或重量而往下垂。

Example / 例子：

• The flower drooped after not being watered. 花因没浇水而垂下来了。
• His shoulders drooped in disappointment. 他因为失望而耷拉着肩。

2. to lose energy, spirit, or enthusiasm

English: When a person’s mood or energy becomes low or weak. 中文：（情绪）低落，无精打采。

Example / 例子：

• She drooped after hearing the bad news. 听到坏消息后她整个人都低落了。

3. (eyes) eyelids falling partly closed

English: When your eyelids lower because you’re tired or sleepy. 中文：（眼皮）耷拉下来、半闭。

Example / 例子：

• His eyelids drooped as he fell asleep. 他困得眼皮都耷拉下来了。

If you want, I can also give: ✅ synonyms ✅ a bilingual flashcard Just tell me!

Here is the meaning of “misty” in clear English + 中文解释：

misty — meaning

1. filled with mist; slightly foggy

English: When there is a light fog or tiny water droplets in the air. 中文： 有薄雾的；起雾的；朦胧的。

Example / 例子：

• It was a misty morning. 那是一个有薄雾的早晨。
• The mountains looked misty in the distance. 远处的山看起来雾气朦胧。

2. (eyes) watery, blurry from tears

English: When someone’s eyes look blurry because they are about to cry or emotional. 中文：（眼睛）含泪的，湿润的，模糊的。

Example / 例子：

• Her eyes grew misty as she remembered her childhood. 她回忆起童年时眼睛湿润了。

3. unclear or hard to see

English: Something not sharp or clear, visually or emotionally. 中文： 模糊的、不清晰的（也可形容记忆、感觉）。

Example / 例子：

• I have a misty memory of that day. 我对那天只有模糊的记忆。

If you want, I can also give: ✅ synonyms ✅ more example sentences ✅ a bilingual flashcard version Just let me know!

“sweetums” is an informal, cute, affectionate English word. Here is the meaning in simple English + 中文解释：

sweetums — meaning

1. a cute nickname for someone you love

English: A playful, sweet nickname used for a boyfriend/girlfriend, partner, spouse, child, or someone you care about. Similar to honey, sweetie, baby. 中文： 可爱、亲昵的昵称，用来称呼亲密的人，如伴侣、小孩等；相当于“甜心”“宝贝”“亲爱的”。

Example / 例子：

• Come here, sweetums! 来这边，甜心！
• Goodnight, sweetums. 晚安，宝贝。

2. silly or exaggerated cute nickname

English: Often used in a joking or exaggerated way to sound extra sweet or dramatic. 中文： 有时带一点夸张、搞笑的甜蜜称呼。

Example / 例子：

• Okay, sweetums, calm down. 好啦，甜心，冷静点。

If you want, I can also: ✅ give synonyms ✅ translate sentences ✅ create flashcards (English ↔ Chinese) Just let me know!

Here is the meaning of “belch” in clear English + 中文解释：

belch — meaning

1. to burp loudly (most common)

English: When gas comes out from the stomach through the mouth with a loud sound. 中文： 打嗝，尤其是响亮的打嗝。

Example / 例子：

• He drank soda and belched loudly. 他喝了汽水后大声打嗝。

2. (objects / machines) to send out smoke, gas, or steam suddenly

English: When something releases smoke, fire, gas, or steam forcefully. 中文：（机器、火山等）喷出烟雾、火焰或气体。

Example / 例子：

• The factory chimneys belched black smoke. 工厂的烟囱喷出黑烟。
• The volcano belched ash into the sky. 火山喷出火山灰。

3. (figurative) to produce something in a forceful, sudden way

English: Used metaphorically to mean releasing something powerfully. 中文： 比喻强力地喷出、发出某物。

If you want, I can also give: ✅ synonyms ✅ example sentences ✅ a bilingual flashcard version Just tell me!

Here is the meaning of “snarled” in clear English + 中文解释：

snarled — meaning

1. (animals) growled angrily with teeth showing

English: When an animal (like a dog or wolf) makes a low, angry sound while showing its teeth. 中文：（动物）龇牙咧嘴地低吼、咆哮。

Example / 例子：

• The dog snarled at the stranger. 狗对陌生人龇牙低吼。

2. (people) spoke in a harsh, angry voice

English: When a person says something in an angry, sharp, unfriendly way. 中文：（人）用愤怒、尖锐、粗暴的口气说话。

Example / 例子：

• “Get out!” he snarled. “滚出去！”他怒声吼道。

3. (objects / traffic) became tangled or jammed

English: Used to describe something twisted, tangled, or blocked (e.g., hair, wires, traffic). 中文： 形容东西缠在一起、打结、堵塞。

Example / 例子：

• Her hair was snarled from the wind. 她的头发被风吹得打结了。
• Traffic was snarled for miles. 交通堵塞了好几英里。

If you want, I can give synonyms, more examples, or translate sentences using “snarled.”

It looks like you might be asking about the word “hooting.” Here are the meanings in simple English + 中文解释：

hooting — meaning

1. (most common) the sound an owl makes

English: A loud “hoo-hoo” sound made by an owl. 中文： 猫头鹰发出的“咕咕”叫声。

Example / 例子：

• We heard owls hooting in the forest. 我们听到森林里有猫头鹰在咕咕叫。

2. shouting or yelling loudly (informal)

English: When people shout, cheer, or laugh loudly. 中文： （非正式）人大声喊叫、起哄、嘲笑。

Example / 例子：

• The crowd was hooting with laughter. 人群在大声笑、起哄。

3. honking (cars)

English: Sometimes used to describe a car horn sounding. 中文： 有时也用来形容汽车按喇叭声。

Example / 例子：

• Cars were hooting in traffic. 车子在按喇叭。

If you want, I can also give: ✅ synonyms 同义词 ✅ pronunciation 发音 ✅ example sentences 例句 Just tell me!

EN: Electric current is the rate at which electric charge flows through a conductor. - Unit: ampere (A). - Current in a circuit is associated with energy transfer; devices transform electrical energy into other forms.

中文：电流是电荷通过导体的流动速率。 - 单位：安培（A）。 - 电路中的电流对应能量的传递，用电器把电能转化为其他形式。

EN: Mass is the amount of matter in an object and a measure of its inertia (resistance to changes in motion). - Unit: kilogram (kg). - In this Topic, mass affects both KE (1/2 mv^2) and GPE (m g Δh) linearly.

中文：质量表示物体所含物质的多少，也是惯性大小的量度（抗拒运动状态改变的能力）。 - 单位：千克（kg）。 - 在本主题中，质量会线性影响动能（1/2 mv^2）和重力势能（m g Δh）。

EN: Acceleration due to gravity (g) near Earth is about 9.8 m/s^2. - It is the acceleration of a freely falling object (ignoring air resistance). - g is used in gravitational potential energy: GPE = m g Δh.

中文：近地面重力加速度 g ≈ 9.8 m/s^2。 - 忽略空气阻力时，自由落体的加速度约为 g。 - 在重力势能公式中使用：GPE = m g Δh。

EN: Change in height (Δh) is the difference between final and initial height. - It tells how much gravitational potential energy changes: ΔGPE = m g Δh. - Δh depends on the chosen reference level and can be positive or negative.

中文：高度变化（Δh）是末高度与初高度之差。 - 它决定重力势能的变化：ΔGPE = m g Δh。 - Δh 与所选参考高度有关，可为正也可为负。

EN: Velocity is speed with direction (a vector). - Unit: metres per second (m/s). - Because KE ∝ v^2, doubling velocity makes kinetic energy 4 times larger (if mass is the same).

中文：速度（velocity）是带方向的速率（矢量）。 - 单位：米每秒（m/s）。 - 因为动能与 v^2 成正比，同质量时速度加倍，动能会变为 4 倍。

EN: A kilojoule (kJ) is 1000 joules. - We often use kJ because the joule is a small unit in everyday situations.

中文：千焦（kJ）= 1000 焦耳（J）。 - 由于焦耳较小，生活和化学/食品能量等常用千焦表示。

EN: The joule (J) is the SI unit of energy. - 1 J = 1 N·m = 1 kg·m^2/s^2. - Rough sense of scale: lifting a 0.10 kg object by 1 m requires about 1 J of gravitational potential energy.

中文：焦耳（J）是能量的国际单位。 - 1 J = 1 N·m = 1 kg·m^2/s^2。 - 直观尺度：把约 0.10 kg 的物体抬高 1 m，大约需要 1 J 的重力势能。

EN: Ultraviolet (UV) radiation is electromagnetic radiation with wavelengths shorter than visible violet light. - UV photons have relatively high energy and can cause chemical changes (e.g., sunburn).

中文：紫外线（UV）是波长比紫光更短的电磁辐射。 - 紫外光子能量较高，可能引起化学变化（如晒伤）。

EN: An energy transformation is efficient if a large fraction of the input energy becomes useful output. - Efficiency = (useful output energy) / (input energy) × 100%. - Real systems are never 100% efficient because some energy becomes unwanted thermal/sound energy due to friction and resistance.

中文：能量转化“高效”表示输入能量中有较大比例变成了有用的输出。 - 效率 = 有用输出能量 / 输入能量 × 100%。 - 真实系统不可能 100% 高效，因为摩擦/电阻等会使部分能量转为不想要的热能/声能。

EN: Friction is a force that opposes motion between surfaces (or through air/water). - Friction converts mechanical energy into less useful forms, mainly thermal energy (and sometimes sound). - This is why motion usually slows down without additional energy input.

中文：摩擦力是阻碍相对运动的力（包括表面摩擦和空气/水阻力）。 - 摩擦会把机械能转化为较难利用的热能（有时还有声能）。 - 因此没有持续能量输入时，运动往往会逐渐减慢。

EN: Sound energy is energy carried by vibrations (mechanical waves) traveling through matter. - Sound requires a medium (air, water, solids) and cannot travel through a vacuum. - When absorbed, sound energy often transforms into thermal energy.

中文：声能是由振动产生并通过介质传播的机械波所携带的能量。 - 声音需要介质（空气/水/固体），真空中不能传播。 - 被吸收后通常转化为热能。

EN: Radiant energy is energy carried by electromagnetic radiation (waves/photons). - It includes visible light, infrared, and ultraviolet. - When absorbed by matter, radiant energy often transforms into thermal energy.

中文：辐射能是由电磁辐射（电磁波/光子）携带的能量。 - 包括可见光、红外线、紫外线等。 - 被物质吸收后常转化为热能。

EN: Infrared is electromagnetic radiation with wavelengths longer than visible red light. - It is often experienced as warmth because absorbing infrared increases thermal energy.

中文：红外线是波长比红光更长的电磁辐射。 - 常被感受到“热”，因为吸收红外线会增加物体的热能。

EN: Nuclear energy is energy stored in atomic nuclei. - It can be released by fission, fusion, or radioactive decay. - Nuclear energy has a very high energy density compared with chemical energy.

中文：核能是储存在原子核中的能量。 - 可通过核裂变、核聚变或放射性衰变释放。 - 相比化学能，核能的能量密度非常高。

EN: Magnetic potential energy is stored due to the position/orientation of magnets in a magnetic field. - If released, this stored energy can transform into kinetic energy as objects move.

中文：磁势能是由磁体在磁场中的位置/方向而储存的能量。 - 释放后可转化为动能，使物体发生运动。

EN: Heat is thermal energy that is transferred from a warmer object to a cooler one because of a temperature difference. - Heat is energy in transit (not a substance stored inside an object). - Unit: joule (J).

中文：热量是由于温度差从高温物体传递到低温物体的热能。 - 热量强调“传递中的能量”，不是物体内部的一种“物质”。 - 单位：焦耳（J）。

EN: Thermal energy is the total kinetic energy of the particles in matter (microscopic motion). - Generally, higher temperature means greater average particle kinetic energy. - Thermal energy can be transferred as heat when there is a temperature difference.

中文：热能（更准确地说是与温度有关的内能部分）来自物质内部粒子的微观运动动能总和。 - 温度越高，粒子平均动能越大。 - 有温差时，热能会以“热量”的形式传递。

EN: Electrical potential energy is stored energy due to separated electric charges (electric potential difference/voltage). - A battery stores electrical potential energy and can transfer it to a circuit. - In a circuit it can transform into other forms (light, thermal, sound, motion).

中文：电势能是由于电荷分离而储存的能量（与电势差/电压有关）。 - 电池储存电势能，并可把能量传递到电路中。 - 在电路中可转化为光、热、声或机械运动等其他形式。

EN: Electrical kinetic energy refers to the energy associated with moving electric charges (electric current). - When charges move through a device, the energy can transform into light, heat, or motion.

中文：电荷运动（电流）所携带的能量可理解为“电的动能”。 - 电流通过用电器时，能量可以转化为光、热或机械运动等。

EN: Chemical potential energy is stored in chemical bonds. - Fuels, food, and batteries store chemical potential energy. - During chemical reactions it can transform into thermal, radiant (light), electrical, and mechanical energy.

中文：化学势能是储存在化学键中的能量。 - 燃料、食物、电池都储存化学势能。 - 化学反应中它可转化为热能、光（辐射）能、电能、机械能等。

EN: Gravitational potential energy (GPE) is energy stored because of height in a gravitational field. - It depends on mass, gravitational field strength (g), and change in height. - Near Earth: GPE = m g Δh (relative to a chosen reference level).

中文：重力势能（GPE）是物体由于处在重力场中的高度而具有的能量。 - 与质量、重力加速度 g，以及高度变化 Δh 有关。 - 近地面常用：GPE = m g Δh（相对于所选参考高度）。

EN: Mechanical kinetic energy is the kinetic energy of the motion of objects (macroscopic motion you can observe). - It depends on mass and velocity: KE = 1/2 mv^2. - It is different from thermal energy, which is microscopic particle motion.

中文：机械动能（机械运动的动能）是可观察到的物体整体运动所具有的动能。 - 与质量和速度有关：KE = 1/2 mv^2。 - 它不同于热能；热能来自微观粒子的无规则运动。

EN: Energy is the ability to cause change in a system or do work. - Energy appears in different forms (mechanical, thermal, chemical, electrical, radiant, etc.). - Energy can be transferred between a system and its surroundings, or transformed from one form to another. - The SI unit of energy is the joule (J).

中文：能量是使系统发生变化或对物体做功的能力。 - 能量有多种形式（机械、热、化学、电、辐射等）。 - 能量既可以在系统与环境之间传递，也可以在不同形式之间转化。 - 能量的国际单位是焦耳（J）。

EN: A system is the part of the universe you choose to study (the object(s) under observation). - The system boundary is defined by you, depending on the question you are trying to answer. - Energy can enter/leave the system, so tracking the system helps you describe energy transfers.

中文：系统是你选择研究的那一部分宇宙（被观察/被分析的对象或对象集合）。 - 系统边界由研究者根据问题来定义，可大可小。 - 能量可以在系统与环境之间传递，因此先定义系统有助于分析能量变化。

EN: Potential energy is stored energy due to position or configuration. - It can be transformed into kinetic energy and other forms. - Examples include gravitational, chemical, electrical, and magnetic potential energy.

中文：势能是由于位置或结构/状态而“储存”的能量。 - 势能可以转化为动能以及其他形式的能量。 - 常见类型：重力势能、化学势能、电势能、磁势能等。

EN: Kinetic energy is the energy of motion. Anything that is moving has kinetic energy. - For a moving object, kinetic energy depends on mass and velocity. - In many Grade-10 problems: KE = 1/2 mv^2 (always ≥ 0).

中文：动能是由于运动而具有的能量，任何在运动的物体都有动能。 - 动能与质量和速度有关。 - 常用公式：KE = 1/2 mv^2（动能一定是非负的）。

EN: The law of conservation of energy states that energy cannot be created or destroyed. - Total energy stays constant in an isolated system. - What changes is the form of energy and where it is (system vs. surroundings). - Some transformed energy becomes less useful (often as thermal energy and sound) due to friction and other processes.

中文：能量守恒定律：能量不会凭空产生，也不会凭空消失。 - 对于孤立系统，总能量保持不变。 - 改变的是能量的形式以及能量所在的位置（系统或环境）。 - 由于摩擦等原因，部分能量会转化为较难利用的热能/声能，但总量仍守恒。

EN: The surroundings are everything outside the system boundary. - Surroundings can interact with the system by transferring energy (and sometimes matter). - In many problems, you only include the nearby surroundings that actually interact.

中文：环境（周围环境）是系统边界之外的所有事物。 - 环境可以通过能量（有时也包括物质）与系统发生相互作用。 - 解题时通常只考虑与系统有实际相互作用的那部分环境。

“Hereditary / 遗传的” — with appropriate images

English — hereditary (thorough explanation)

1) Core meaning

Hereditary means passed from parents to offspring through genes. If something is hereditary, it can be inherited biologically because it is encoded in DNA.

2) Biological mechanism

• Genes are segments of DNA located on chromosomes.

• Each person usually inherits two versions of a gene (alleles):

• one from the mother

• one from the father

• These alleles influence:

• traits (eye color, hair texture)

• disease risk (some genetic disorders)

3) Traits vs. conditions

• Hereditary traits → visible or functional characteristics
• Hereditary diseases → conditions influenced by inherited genes

Important:

• Hereditary ≠ contagious
• Hereditary ≠ guaranteed (a gene can increase risk without causing disease)

4) Common inheritance patterns

• Autosomal dominant: one allele is enough to show the trait
• Autosomal recessive: two recessive alleles are required
• X-linked: gene is on the X chromosome, affecting males and females differently

5) Example sentences

• “Eye color is partly hereditary.”
• “This disease is hereditary, but symptoms may not appear in every carrier.”

中文 — hereditary（遗传的） 详细解释

1) 核心含义

遗传的（hereditary） 指 通过基因从父母传给子女的性状或特征，本质上与 DNA 有关。

2) 生物学原理

• 基因存在于 染色体 上，由 DNA 构成
• 人通常从父母各获得一份 等位基因

• 等位基因共同决定：

• 外貌或生理性状

• 是否携带某些遗传性疾病的风险

3) 重要区分

• 遗传 ≠ 传染（不是病菌传播）

• 遗传 ≠ 一定会发生

• 有些人携带基因，但并不表现症状

4) 常见遗传方式（中学重点）

• 显性遗传：一份显性基因即可表现
• 隐性遗传：需要两份隐性基因
• 伴性遗传：基因位于 X 染色体上

5) 中文例句

• “这种特征是遗传的，会在家族中出现。”
• “这是遗传性疾病，但并非每个携带者都会发病。”

学习提示（给 Biology / Genetics）

看到 hereditary，可以立刻联想到这条逻辑链： DNA → 基因 → 等位基因 → 遗传方式 → 性状 / 疾病

如果你愿意，我可以下一步把它做成 中英对照生物词卡（flashcards），或直接嵌入你之前的 Unit 1 DNA HTML 教学页面。

English — incomplete dominance (thorough explanation)

1) What incomplete dominance means (core idea)

Incomplete dominance is an inheritance pattern in which neither allele is completely dominant, so the heterozygous phenotype is an intermediate (blended) form of the two homozygous phenotypes.

Incomplete dominance = blending of traits in heterozygotes

2) How incomplete dominance works

• Two different alleles affect the trait
• In a heterozygous individual, both alleles partially influence the outcome
• The result looks like a mix, not one trait hiding the other

3) Classic example (Science 10 favorite): flower color

Let:

• R = red flowers
• W = white flowers

Cross: RR × WW

Offspring:

• RW → pink flowers

📌 Pink is not a new allele; it’s the intermediate phenotype.

4) Incomplete dominance in Punnett squares

Parents: RW × RW

Possible offspring:

• RR → red
• RW → pink
• RW → pink
• WW → white

Phenotype ratio: 1 red : 2 pink : 1 white

📌 Notice: phenotype ratio = genotype ratio in incomplete dominance.

5) Incomplete dominance vs other patterns (very important)

| Pattern | Heterozygous result | Example | | ------------------------ | ------------------------- | ------------------ | | Dominant–recessive | Dominant trait only | Brown eyes | | Incomplete dominance | Blended trait | Red × white → pink | | Codominance | Both traits fully visible | AB blood type |

6) Why incomplete dominance matters

Incomplete dominance:

• Explains traits that don’t follow simple dominance
• Increases visible variation in populations
• Is common in plants, animals, and humans (for some traits)

One-sentence exam summary

Incomplete dominance occurs when heterozygous individuals show an intermediate, blended phenotype.

中文 — incomplete dominance（不完全显性） 详细解释

1) 什么是不完全显性（核心概念）

不完全显性是指： 两个等位基因中没有一个完全显性，杂合体表现为中间型性状。

不完全显性 = 性状混合表现

2) 不完全显性的表现特点

• 显性不能完全压制另一等位基因
• 杂合体表现为中间状态
• 性状不是“要么这个，要么那个”

3) 经典例子（考试常考）

花的颜色：

• 红花（RR）
• 白花（WW）

杂交后：

• RW → 粉红色花

📌 粉红不是新基因，而是红和白的中间表现。

4) 潘尼特方格中的不完全显性

父母：RW × RW

后代比例：

• 1 红（RR）
• 2 粉（RW）
• 1 白（WW）

👉 表现型比例 = 基因型比例

5) 不完全显性 vs 共显性（重点区分）

| 遗传方式 | 表现结果 | | ----- | ---------- | | 不完全显性 | 中间型（混合） | | 共显性 | 两种性状同时清楚出现 |

一句话考试版总结

不完全显性指杂合体表现为两种性状的中间型。

如果你愿意，我可以把 dominant / recessive / incomplete dominance / codominance 整理成 Science 10 中英对照对比表、潘尼特方格练习或互动闪卡，非常适合系统复习与教学。

不完全显性（incomplete dominance） EN: A condition in which neither allele for a gene completely conceals the presence of the other, resulting in an intermediate expression of a trait. Example: In four o’clock plants, red flowers crossed with white flowers produce pink offspring, an intermediate phenotype. 中文：两种等位基因互不完全掩盖对方，从而产生介于双亲之间的中间型表现。 例子：紫茉莉红花与白花杂交产生粉红花，就是不完全显性的例子。

English — traits (thorough explanation)

1) What traits are (core idea)

Traits are characteristics or features of an organism. They describe how an organism looks, behaves, or functions.

Trait = a characteristic of a living thing

Traits can be:

• Inherited (passed down from parents)
• Influenced by the environment
• Or a combination of both

2) Types of traits

A) Inherited (genetic) traits

These traits are controlled by genes and passed from parents to offspring.

Examples:

• Eye color
• Hair color and texture
• Blood type
• Natural height potential

📌 These traits are present from birth.

B) Acquired (environmental) traits

These traits develop due to life experiences or environment.

Examples:

• Suntan
• Muscle strength from exercise
• Scars
• Language spoken

📌 These traits are not inherited genetically.

C) Traits influenced by both genes and environment

Many traits result from both heredity and environment.

Examples:

• Height (genes + nutrition)
• Intelligence (genes + education)
• Athletic ability (genes + training)

3) Traits in genetics (Science 10 focus)

In genetics, traits are:

• Controlled by genes
• Each gene may have different alleles
• Alleles can be dominant or recessive

📌 Example:

• Brown eyes (dominant)
• Blue eyes (recessive)

Punnett squares are used to predict traits in offspring.

4) Genotype vs phenotype (important distinction)

| Term | Meaning | Example | | --------- | ------------------- | ---------- | | Genotype | Genetic makeup | Bb | | Phenotype | Physical expression | Brown eyes |

📌 Traits are what you see (phenotype), based on genes (genotype).

5) Why traits matter

Traits:

• Explain similarities and differences between organisms
• Help scientists study inheritance
• Are the basis of natural selection and evolution

One-sentence exam summary

Traits are characteristics of organisms that can be inherited, acquired, or influenced by both genes and environment.

中文 — traits（性状 / 特征） 详细解释

1) 什么是性状（核心概念）

性状（traits）是指生物表现出来的特征或特点。

性状 = 生物的特征

2) 性状的类型

① 遗传性状

由基因决定，从父母传给子女。

例子：

• 眼睛颜色
• 头发颜色
• 血型

② 获得性状

由环境或经历造成。

例子：

• 晒黑
• 肌肉增强
• 疤痕

③ 遗传 + 环境共同影响

• 身高
• 学习能力
• 运动能力

3) 遗传学中的性状（考试重点）

• 性状由基因控制
• 基因有不同等位基因
• 等位基因有显性和隐性

4) 基因型 vs 表现型

| 概念 | 含义 | | --- | ---- | | 基因型 | 基因组合 | | 表现型 | 外在性状 |

一句话考试版总结

性状是生物的特征，由遗传和环境共同决定。

如果你需要，我可以把 traits / inherited traits / acquired traits / Punnett squares 做成 Science 10 中英对照闪卡或课堂练习题，直接用于教学或复习。

性状（trait） EN: An inherited characteristic, such as eye colour or hair colour. Example: Traits like seed colour in pea plants or the ability to taste bitterness are controlled by genes. 中文：一种可遗传的特征，如眼睛颜色、头发颜色等。 例子：豌豆的种子颜色、是否能尝出苦味，都是由基因控制的性状。

English — alleles (thorough explanation)

1) What alleles are (core idea)

Alleles are different versions of the same gene. They control variations of a trait, such as eye color or flower color.

Allele = one version of a gene

Each gene can have two or more alleles, but an individual organism usually carries two alleles per gene (one from each parent).

2) Where alleles are found

• Genes are located on chromosomes
• Alleles sit at the same position (locus) on homologous chromosomes
• One allele comes from the mother
• One allele comes from the father

📌 This is why offspring show traits from both parents.

3) Example of alleles (simple)

Trait: Seed color

• Y = yellow
• y = green

Possible allele combinations:

• YY
• Yy
• yy

These combinations affect the trait that appears.

4) Dominant vs recessive alleles (Science 10 focus)

Dominant allele

• Shown with a capital letter (A)
• Expressed if at least one copy is present

Recessive allele

• Shown with a lowercase letter (a)
• Expressed only if two copies are present

📌 Example:

• Aa → dominant trait shows
• aa → recessive trait shows

5) Alleles, genotype, and phenotype (key relationship)

| Term | Meaning | Example | | --------- | ------------------ | ---------- | | Allele | Version of a gene | A or a | | Genotype | Allele combination | Aa | | Phenotype | Physical trait | Brown eyes |

Alleles determine the genotype, which determines the phenotype.

6) Alleles in Punnett squares

Punnett squares:

• Show how alleles from parents combine
• Predict possible offspring genotypes
• Estimate trait probabilities

📌 Example: Parents: Aa × Aa

• Possible offspring: AA, Aa, Aa, aa

7) Why alleles are important

Alleles:

• Explain variation within a species
• Help predict inheritance patterns
• Are the basis of genetics and evolution
• Allow populations to adapt over time

One-sentence exam summary

Alleles are different versions of the same gene that determine variations in traits.

中文 — alleles（等位基因） 详细解释

1) 什么是等位基因（核心概念）

等位基因（alleles）是指同一基因的不同版本，决定同一性状的不同表现。

等位基因 = 同一基因的不同形式

2) 等位基因在哪里

• 基因位于染色体上
• 等位基因位于同源染色体的相同位置
• 一个来自母亲，一个来自父亲

3) 等位基因举例

性状：豌豆高度

• T = 高
• t = 矮

组合可能是：

• TT
• Tt
• tt

4) 显性与隐性等位基因（必考）

• 显性等位基因：只要有一个就会表现
• 隐性等位基因：必须两个都有才表现

📌 Tt → 显性性状 📌 tt → 隐性性状

5) 等位基因与性状的关系

• 等位基因 → 基因型
• 基因型 → 表现型

一句话考试版总结

等位基因是控制同一性状的不同基因形式。

如果你愿意，我可以把 alleles → genotype → phenotype → Punnett squares 整理成 Science 10 中英对照闪卡或互动练习，直接用于复习或教学。

等位基因（allele） EN: Different versions of the same gene that may produce different forms of a trait. Example: For pea flower colour, one allele codes for purple and another for white. 中文：位于同源染色体相同位置、控制同一性状的基因的不同形式。 例子：例如花色基因可以有紫花等位基因和白花等位基因。

EN - Meaning: Collections that store biological samples (like blood, tissue) and associated data for research. - Key idea: Biobanks support medical research but require strong policies for consent, privacy, and data security.

中文 - 含义：生物样本库：保存血液、组织等样本及相关数据，用于科研的收集与存储系统。 - 关键点：有助于医学研究，但需要完善的知情同意、隐私与数据安全制度。

Images - https://en.wikipedia.org/wiki/Special:Search?search=biobank - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=biobank

EN - Meaning: Information encoded in DNA that can influence traits and health. - Key idea: Genetic information raises privacy and ownership questions (e.g., data storage, sharing, and consent).

中文 - 含义：遗传信息：DNA 中编码的信息，会影响性状与健康。 - 关键点：会引发隐私与所有权问题（如存储、共享与知情同意）。

Images - https://en.wikipedia.org/wiki/Special:Search?search=genetic%20information%20privacy - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=genetic%20testing%20privacy

EN - Meaning: A moth species whose caterpillars can defoliate many tree species; considered invasive in some regions. - Key idea: Defoliation weakens trees and can disrupt forest ecosystems.

中文 - 含义：亚洲舞毒蛾：幼虫能大量取食树叶，影响多种树种；在一些地区被视为入侵害虫。 - 关键点：取食导致落叶会削弱树木并扰乱森林生态。

Images - https://en.wikipedia.org/wiki/Special:Search?search=Asian%20gypsy%20moth - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=Asian%20gypsy%20moth

EN - Meaning: A serious disease of elm trees caused by fungi and spread by bark beetles. - Key idea: It has killed many elm trees in North America and Europe.

中文 - 含义：荷兰榆树病：由真菌引起并通过树皮甲虫传播的榆树严重病害。 - 关键点：在北美与欧洲造成大量榆树死亡。

Images - https://en.wikipedia.org/wiki/Special:Search?search=Dutch%20elm%20disease - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=Dutch%20elm%20disease

EN - Meaning: Fertilization that occurs outside the body (in a lab), followed by embryo transfer to the uterus. - Key idea: IVF can help couples conceive when natural fertilization is difficult.

中文 - 含义：体外受精（IVF）：在体外（实验室）完成受精，形成胚胎后再移植入子宫。 - 关键点：可帮助自然受精困难的夫妇实现怀孕。

Images - https://en.wikipedia.org/wiki/Special:Search?search=in%20vitro%20fertilization - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=in%20vitro%20fertilization

EN - Meaning: A non-native species that spreads and causes harm to ecosystems, economies, or health. - Key idea: Invasive species can outcompete native species and reduce biodiversity.

中文 - 含义：入侵物种：外来物种扩散并对生态系统、经济或健康造成危害。 - 关键点：可能与本地物种竞争并降低生物多样性。

Images - https://en.wikipedia.org/wiki/Special:Search?search=invasive%20species - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=invasive%20species

EN - Meaning: To develop into a specialized cell type with a specific structure and function. - Key idea: Differentiation explains how the same DNA can produce many different cell types.

中文 - 含义：分化：细胞发育成为具有特定结构与功能的专门细胞类型。 - 关键点：分化说明同一套 DNA 如何形成不同类型的细胞。

Images - https://en.wikipedia.org/wiki/Special:Search?search=cell%20differentiation - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=cell%20differentiation

EN - Meaning: Stem cells found in adult tissues (e.g., bone marrow) that can produce certain specialized cells. - Key idea: Adult stem cells are often used clinically (e.g., blood stem cell transplants) and raise fewer ethical concerns than embryonic stem cells.

中文 - 含义：成体干细胞：存在于成人组织（如骨髓）中的干细胞，可产生特定类型的专门细胞。 - 关键点：临床应用较常见（如造血干细胞移植），伦理争议通常小于胚胎干细胞。

Images - https://en.wikipedia.org/wiki/Special:Search?search=adult%20stem%20cell - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=adult%20stem%20cell

EN - Meaning: A reproductive technology where sperm are placed into the female reproductive tract without sexual intercourse. - Key idea: Can help when there are fertility challenges; used in humans and animal breeding.

中文 - 含义：人工授精：不通过性交，而将精子置入女性生殖道以实现受孕的技术。 - 关键点：可帮助不孕不育情况，也广泛用于动物繁殖。

Images - https://en.wikipedia.org/wiki/Special:Search?search=artificial%20insemination - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=artificial%20insemination

EN - Meaning: Cells that can self-renew and can differentiate into specialized cell types. - Key idea: Stem cells are important for development and can be used in regenerative medicine research.

中文 - 含义：干细胞：能自我更新，并可分化为多种专门细胞类型的细胞。 - 关键点：对发育很重要，也用于再生医学研究。

Images - https://en.wikipedia.org/wiki/Special:Search?search=stem%20cell - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=stem%20cell

EN - Meaning: Identifying an individual using DNA patterns (genetic markers). - Key idea: Used in forensics, paternity testing, and identification; not the same as sequencing the entire genome.

中文 - 含义：DNA 指纹鉴定：利用 DNA 的特征性片段/标记来识别个体。 - 关键点：用于法医、亲子鉴定与身份识别；并不等同于测完整基因组。

Images - https://en.wikipedia.org/wiki/Special:Search?search=DNA%20fingerprinting - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=DNA%20fingerprinting

EN - Meaning: Weeds that become difficult to control, often due to herbicide resistance. - Key idea: Repeated use of the same herbicide can select for resistant weed populations.

中文 - 含义：超级杂草：难以控制的杂草，常与除草剂抗性有关。 - 关键点：长期反复使用同一种除草剂可能筛选出抗性杂草种群。

Images - https://en.wikipedia.org/wiki/Special:Search?search=herbicide%20resistance%20weeds - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=herbicide%20resistance%20weeds

EN - Meaning: Treating a disease by adding, replacing, or altering genes in a patient’s cells. - Key idea: Often uses a vector (frequently a virus) to deliver a functional gene.

中文 - 含义：基因治疗：通过向患者细胞中添加/替换/改变基因来治疗疾病。 - 关键点：常用载体（常见为病毒）把正常基因送入细胞。

Images - https://en.wikipedia.org/wiki/Special:Search?search=gene%20therapy - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=gene%20therapy

EN - Meaning: Crop plants engineered to survive a herbicide that would normally kill them. - Key idea: Enables weed control by spraying, but can lead to selection for herbicide-resistant weeds.

中文 - 含义：耐除草剂作物：被改造后能耐受本应杀死它们的除草剂。 - 关键点：便于喷洒除草剂控草，但可能促使杂草选择出耐药性。

Images - https://en.wikipedia.org/wiki/Special:Search?search=herbicide-resistant%20crop - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=herbicide-resistant%20crop

EN - Meaning: A lack of vitamin A, which is important for vision, immune function, and development. - Key idea: Vitamin A deficiency can increase health risks; some GM crops aim to improve nutrition.

中文 - 含义：维生素 A 缺乏：维生素 A 不足，会影响视力、免疫与生长发育。 - 关键点：缺乏会增加健康风险；一些转基因作物用于提高营养。

Images - https://en.wikipedia.org/wiki/Special:Search?search=vitamin%20A%20deficiency - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=vitamin%20A%20deficiency

EN - Meaning: Corn genetically engineered to produce Bt toxin (from Bacillus thuringiensis) that kills certain insect pests. - Key idea: Can reduce insect damage, but may raise concerns about resistance and ecological effects.

中文 - 含义：Bt 玉米：转基因玉米，可产生 Bt 毒素（来源于苏云金芽孢杆菌），用来杀死特定害虫。 - 关键点：可减少虫害，但也可能引发抗性与生态影响等问题。

Images - https://en.wikipedia.org/wiki/Special:Search?search=Bt%20corn - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=Bt%20corn

EN - Meaning: A genetically modified rice designed to produce provitamin A (β-carotene) in the grain. - Key idea: Intended to reduce vitamin A deficiency where rice is a staple food.

中文 - 含义：黄金大米：一种转基因水稻，使稻米籽粒产生前体维生素 A（β-胡萝卜素）。 - 关键点：目标是帮助减少以大米为主食地区的维生素 A 缺乏。

Images - https://en.wikipedia.org/wiki/Special:Search?search=Golden%20Rice - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=Golden%20Rice

EN - Meaning: A pigment that the body can convert into vitamin A (a “provitamin A”). - Key idea: Increasing β-carotene in foods can help address vitamin A deficiency.

中文 - 含义：β-胡萝卜素：一种色素，人体可将其转化为维生素 A（维生素 A 前体）。 - 关键点：提高食物中的 β-胡萝卜素含量可帮助缓解维生素 A 缺乏。

Images - https://en.wikipedia.org/wiki/Special:Search?search=beta-carotene - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=beta-carotene

EN - Meaning: Organisms whose genetic material has been modified using biotechnology. - Key idea: “Genetically modified” includes transgenic changes (adding foreign DNA) and other DNA sequence changes.

中文 - 含义：基因改造生物：遗传物质经生物技术改动的生物体。 - 关键点：既包括转基因（导入外源 DNA），也包括其他 DNA 序列改变。

Images - https://en.wikipedia.org/wiki/Special:Search?search=genetically%20modified%20organism - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=genetically%20modified%20organism

EN - Meaning: Genetically modified organisms; organisms whose DNA has been altered using biotechnology. - Key idea: GMOs can be used in medicine and agriculture, but they can also raise environmental and health concerns.

中文 - 含义：GMO（基因改造生物）：通过生物技术改变过 DNA 的生物体。 - 关键点：在医药与农业中有应用，但也可能引发环境与健康方面的担忧。

Images - https://en.wikipedia.org/wiki/Special:Search?search=genetically%20modified%20organism - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=genetically%20modified%20organism

EN - Meaning: An organism that has a gene inserted from another species. - Key idea: Transgenic organisms are one type of genetically modified organism (GMO).

中文 - 含义：转基因生物：基因组中导入了来自其他物种基因的生物体。 - 关键点：转基因生物是 GMO（基因改造生物）的一种。

Images - https://en.wikipedia.org/wiki/Special:Search?search=transgenic%20organism - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=transgenic%20organism

EN - Meaning: Directly changing an organism’s genetic material in a targeted way. - Key idea: Genetic engineering can include inserting genes, editing DNA sequences, or changing gene expression.

中文 - 含义：基因工程：以定向方式直接改变生物体的遗传物质。 - 关键点：可包括导入基因、编辑 DNA 序列或调控基因表达。

Images - https://en.wikipedia.org/wiki/Special:Search?search=genetic%20engineering - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=genetic%20engineering

EN - Meaning: A process where a cell (often bacteria) takes up foreign DNA. - Key idea: Transformation allows bacteria to receive recombinant DNA plasmids and copy the inserted gene.

中文 - 含义：转化：细胞（常指细菌）摄取外源 DNA 的过程。 - 关键点：细菌摄取重组质粒后，可复制插入的基因。

Images - https://en.wikipedia.org/wiki/Special:Search?search=bacterial%20transformation - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=bacterial%20transformation

EN - Meaning: A small circular DNA molecule in bacteria, separate from the main chromosome. - Key idea: Plasmids are commonly used as vectors for gene cloning.

中文 - 含义：质粒：细菌中独立于染色体的小型环状 DNA。 - 关键点：常被用作基因克隆的载体。

Images - https://en.wikipedia.org/wiki/Special:Search?search=plasmid - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=plasmid

EN - Meaning: A carrier DNA molecule used to transfer a gene into a host cell. - Key idea: Plasmids and viruses can act as vectors depending on the application.

中文 - 含义：载体：用于把目标基因带入宿主细胞的 DNA 载体分子。 - 关键点：质粒与病毒都可作为载体（取决于用途）。

Images - https://en.wikipedia.org/wiki/Special:Search?search=genetic%20vector - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=genetic%20vector

EN - Meaning: DNA formed by joining genetic material from different sources. - Key idea: Recombinant DNA is central to gene cloning and many GM techniques.

中文 - 含义：重组 DNA：把来自不同来源的遗传物质连接在一起形成的 DNA。 - 关键点：是基因克隆与许多转基因技术的核心概念。

Images - https://en.wikipedia.org/wiki/Special:Search?search=recombinant%20DNA - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=recombinant%20DNA

EN - Meaning: Using living organisms, cells, or biological molecules to make products or solve problems. - Key idea: Biotechnology includes techniques like cloning, genetic engineering, and gene therapy.

中文 - 含义：生物技术：利用生物体、细胞或生物分子来制造产品或解决问题。 - 关键点：包括克隆、基因工程、基因治疗等技术。

Images - https://en.wikipedia.org/wiki/Special:Search?search=biotechnology - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=biotechnology

EN - Meaning: Producing genetically identical copies of DNA, cells, or organisms. - Key idea: Cloning can refer to copying a gene (gene cloning) or making a whole organism copy.

中文 - 含义：克隆：复制出遗传信息相同的 DNA、细胞或个体。 - 关键点：既可以指基因的复制，也可以指细胞/个体层面的复制。

Images - https://en.wikipedia.org/wiki/Special:Search?search=cloning - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=cloning

EN - Meaning: Making many copies of a specific gene or DNA fragment. - Key idea: A gene is inserted into a vector (often a plasmid) and copied inside a host cell such as bacteria.

中文 - 含义：基因克隆：把某个特定基因/ DNA 片段复制出许多拷贝。 - 关键点：常将基因插入载体（如质粒），再进入宿主细胞（如细菌）中复制。

Images - https://en.wikipedia.org/wiki/Special:Search?search=gene%20cloning - https://commons.wikimedia.org/wiki/Special:MediaSearch?type=image&search=gene%20cloning

Here’s a thorough explanation of “condensed” in both English and 中文, now with appropriate illustrative images from the internet** to help you visualize the meanings. 👇

🌧️ 1. “Condensed” — Gas → Liquid (Science/Physics)

Meaning: When a gas cools down and turns into a liquid, that liquid is described as condensed. This is a common phase change in the water cycle (vapour → water droplets). (Wikipedia)

👉 English explanation:

• Condensation is when gas molecules slow down, come together, and form liquid. (acs.org)
• The liquid formed by this process is condensed water.

👉 中文解释：

• 凝结（condensation）是当气体（如水蒸气）冷却、运动变慢，并聚集成液体时发生的过程。 (Wikipedia)
• 这种形成的液体称为凝结的（水）。

Examples:

• Water vapour condenses on the glass. 水蒸气在玻璃上凝结成水滴。
• Rain forms when condensed water in clouds becomes heavy. 当云中的凝结水变得很重时就会下雨。

🥛 2. “Condensed” — Concentrated Liquid (Food)

Meaning: When much of the water is removed from a liquid (like milk), what’s left is thicker and more concentrated — we call it condensed. (Wikipedia)

👉 English explanation:

• Condensed milk is milk with most water removed — it’s thick and sweet (especially with added sugar). (Wikipedia)

👉 中文解释：

• 炼乳 / 奶浓缩液 是把牛奶的大部分水分蒸发掉后得到的厚而甜的牛奶。 (Wikipedia)

Examples:

• She stirred condensed milk into her coffee. 她往咖啡里加了炼乳。

📝 3. “Condensed” — Shortened Text / Summary

Meaning: When extra details are removed and information is presented in a shorter, tighter form, that version is called condensed.

👉 English:

• A condensed summary keeps the main ideas but is much shorter.

👉 中文：

• 精简版 / 简写版 是指去掉细节，只保留重点内容的版本。

Examples:

• This is a condensed version of the report. 这是报告的精简版。

(Note: Internet images for “condensed text summary diagram” commonly show further visualizations but may be behind paid stock image sites. (Shutterstock))

📌 Quick Bilingual Recap

| Usage (English) | 中文解释 | Key Idea | | ---------------------------- | --------------- | --------------------------- | | condensed water | 凝结水 / 凝结的液体 | gas → liquid | | condensed milk | 炼乳 / 浓缩牛奶 | water removed, concentrated | | condensed summary / text | 精简版 / 简写版 | shorter, fewer details |

If you’d like, I can also generate a printable infographic combining these meanings visually with labels in both English and Chinese. Would you like that? 😊

English — monohybrid cross (thorough explanation)

1) What a monohybrid cross is (core idea)

A monohybrid cross is a genetic cross that examines inheritance of ONE trait only between two parents.

Mono = one Hybrid = genetic cross

So:

Monohybrid cross = a cross involving one trait

2) What kind of trait is studied

The single trait must have two contrasting forms, such as:

• Tall vs short plants
• Round vs wrinkled seeds
• Purple vs white flowers

Each trait is controlled by one gene with two alleles.

3) How a monohybrid cross is shown

A monohybrid cross is usually shown using a 2 × 2 Punnett square.

Example:

• T = tall (dominant)
• t = short (recessive)

Parents: Tt × Tt

Possible offspring genotypes:

• TT
• Tt
• Tt
• tt

4) Genotype and phenotype ratios (exam favorite)

Genotype ratio

• 1 TT : 2 Tt : 1 tt

Phenotype ratio

• 3 tall : 1 short

📌 This 3:1 phenotype ratio is a classic result of a monohybrid cross involving complete dominance.

5) Why monohybrid crosses are important

Monohybrid crosses help students:

• Understand dominant and recessive alleles
• Learn genotype vs phenotype
• Practice Punnett squares
• Predict inheritance patterns

They were essential in Mendel’s experiments with pea plants.

6) When to use a monohybrid cross

Use a monohybrid cross when:

• Only one trait is being studied
• Each parent contributes one allele for that trait
• The problem does not involve codominance or incomplete dominance (unless stated)

One-sentence exam summary

A monohybrid cross studies the inheritance of a single trait using one gene and two alleles.

中文 — monohybrid cross（单性状杂交） 详细解释

1) 什么是单性状杂交（核心概念）

单性状杂交是指： 只研究一个性状遗传情况的杂交实验。

mono（单） + hybrid（杂交）

2) 研究的性状特点

该性状通常：

• 由 一个基因控制
• 有 两种对立表现 例如：
• 高 / 矮
• 圆 / 皱

3) 单性状杂交如何表示

通常使用 2×2 潘尼特方格。

例子：

• T = 高（显性）
• t = 矮（隐性）

父母：Tt × Tt

后代基因型：

• TT
• Tt
• Tt
• tt

4) 常见比例（考试必背）

基因型比例

• 1 : 2 : 1

表现型比例

• 3 : 1

📌 这是孟德尔单性状杂交的经典结果。

5) 单性状杂交的重要性

• 帮助理解显性与隐性
• 区分基因型和表现型
• 是学习遗传学的基础

一句话考试版总结

单性状杂交是研究一个性状遗传规律的杂交实验。

如果你愿意，我可以把 monohybrid vs dihybrid cross 整理成 Science 10 中英对照对比表、练习题或互动 Punnett 方格，非常适合系统复习。

English — gamete (thorough explanation)

1) What a gamete is (core idea)

A gamete is a sex cell used in sexual reproduction. Gametes carry half the normal number of chromosomes and combine during fertilization to form a new organism.

Gamete = a reproductive cell with half the chromosomes

2) Types of gametes

There are two main types:

• Sperm → male gamete
• Egg (ovum) → female gamete

Each parent contributes one gamete to the offspring.

3) Chromosome number (very important)

Gametes are haploid (n), meaning they contain half the usual chromosome number.

Example (humans):

• Body cells: 46 chromosomes (diploid, 2n)
• Gametes: 23 chromosomes (haploid, n)

📌 This ensures that when fertilization occurs, the offspring has the correct chromosome number.

4) How gametes are made — meiosis

Gametes are produced by meiosis, a special type of cell division.

Meiosis:

• Reduces chromosome number by half
• Produces genetically unique gametes
• Creates variation through crossing over and independent assortment

5) Gametes and fertilization

During fertilization:

• One sperm gamete fuses with one egg gamete
• Forms a zygote
• The zygote is diploid (2n) again

6) Why gametes are important

Gametes:

• Allow sexual reproduction
• Maintain correct chromosome numbers
• Increase genetic variation
• Enable inheritance of traits from both parents

One-sentence exam summary

A gamete is a haploid sex cell (sperm or egg) that combines with another during fertilization.

中文 — gamete（配子） 详细解释

1) 什么是配子（核心概念）

配子（gamete）是用于有性生殖的细胞，只含有一半的染色体数目。

配子 = 含一半染色体的生殖细胞

2) 配子的类型

• 精子 → 雄性配子
• 卵子 → 雌性配子

每个亲本提供 一个配子。

3) 染色体数量（必考）

配子是 单倍体（n）：

• 人类体细胞：46 条染色体（2n）
• 配子：23 条染色体（n）

4) 配子如何形成 —— 减数分裂

配子通过 减数分裂产生：

• 染色体数减半
• 形成遗传多样性
• 后代基因组合不同

5) 配子与受精

• 精子 + 卵子 → 受精卵（zygote）
• 受精卵恢复为 二倍体（2n）

一句话考试版总结

配子是含有一半染色体数的生殖细胞，用于有性生殖。

如果你愿意，我可以把 gamete → meiosis → fertilization → zygote 整理成 Science 10 中英对照流程图或互动闪卡，非常适合系统复习与教学。

English — self-pollinate / self-pollination (thorough explanation)

1) What self-pollinate means (core idea)

To self-pollinate means that a plant’s pollen fertilizes its own ovules. The pollen comes from the same flower or from another flower on the same plant.

Self-pollinate = a plant fertilizes itself

2) How self-pollination happens

In flowering plants:

• Pollen is produced in the anther
• Ovules are located in the ovary
• During self-pollination, pollen moves from the anther to the stigma of the same flower (or same plant)

No wind, insects, or animals are required.

3) Why some plants self-pollinate

Self-pollination is useful because it:

• Guarantees reproduction even if pollinators are absent
• Preserves successful traits
• Produces predictable offspring

This is why self-pollinating plants are often used in genetics studies.

4) Classic example (Science 10 context): peas

Pea plants naturally self-pollinate because:

• Their reproductive organs are enclosed
• Pollen reaches the stigma before the flower opens

This allows plants to produce offspring with very similar genotypes.

5) Self-pollination vs cross-pollination (important comparison)

| Feature | Self-pollination | Cross-pollination | | ---------------------- | ---------------- | ----------------- | | Pollen source | Same plant | Different plant | | Genetic variation | Low | High | | Offspring | Very similar | More diverse | | Depends on pollinators | No | Often yes |

📌 Self-pollination increases genetic consistency, while cross-pollination increases variation.

6) Advantages and disadvantages

Advantages

• Reliable reproduction
• No need for pollinators
• Stable traits

Disadvantages

• Less genetic diversity
• Less ability to adapt to change

One-sentence exam summary

Self-pollination occurs when a plant’s pollen fertilizes ovules on the same plant, producing genetically similar offspring.

中文 — self-pollinate（自花授粉） 详细解释

1) 什么是自花授粉（核心概念）

自花授粉是指： 花粉来自同一朵花或同一株植物，并完成受精过程。

自花授粉 = 植物自己给自己授粉

2) 自花授粉如何发生

• 花粉产生于花药
• 受精发生在雌蕊
• 花粉直接从花药传到同一朵花的柱头（或同株另一朵花）

不需要昆虫或风的帮助。

3) 自花授粉的优点

• 保证繁殖成功
• 保持优良性状
• 后代性状稳定

4) 与异花授粉的对比（考试重点）

| 类型 | 特点 | | ---- | ------ | | 自花授粉 | 遗传多样性低 | | 异花授粉 | 遗传多样性高 |

一句话考试版总结

自花授粉是指植物利用自身花粉完成受精的过程。

如果你愿意，我可以把 self-pollination → cross-pollination → genetic variation 整理成 Science 10 中英对照图解或互动练习题，非常适合课堂与考试复习。

English — pea (thorough explanation, genetics focus)

1) What a pea is (core idea)

A pea is the small, round seed found inside a pea pod, produced by the pea plant. Peas are both a food crop and a classic model organism in genetics.

Pea = a seed from a pea plant; widely used to study inheritance

2) Peas in genetics (Science 10 key context)

Pea plants were used by Gregor Mendel to discover the basic laws of inheritance.

Why peas were ideal:

• Easy to grow
• Short generation time
• Clear, contrasting traits
• Can self-pollinate or be cross-pollinated by hand

3) Common pea traits studied (exam favorites)

Mendel studied traits with two clear forms, such as:

| Trait | One form | Other form | | ------------ | -------- | ----------- | | Seed shape | Round | Wrinkled | | Seed color | Yellow | Green | | Flower color | Purple | White | | Pod shape | Inflated | Constricted | | Plant height | Tall | Short |

These traits made it easy to observe dominant and recessive patterns.

4) Peas and Punnett squares

Pea traits are often used in Punnett square problems.

Example:

• R = round seeds (dominant)
• r = wrinkled seeds (recessive)

Cross: Rr × Rr

Results:

• Genotypes: RR, Rr, Rr, rr
• Phenotypes: 3 round : 1 wrinkled

5) Why peas are still used today

Peas helped scientists understand:

• Alleles
• Dominant vs recessive inheritance
• Genotype vs phenotype
• Predictable trait ratios

These principles apply to all sexually reproducing organisms, including humans.

One-sentence exam summary

Peas are seed plants used by Mendel to discover inheritance patterns because they have clear, contrasting traits.

中文 — pea（豌豆） 详细解释（遗传学重点）

1) 什么是豌豆（核心概念）

豌豆（pea）是豌豆植物果荚中的种子，既是食物，也是遗传学研究中的经典材料。

豌豆 = 常用于研究遗传规律的植物种子

2) 豌豆在遗传学中的重要性

孟德尔用豌豆发现了遗传的基本规律。

豌豆适合研究的原因：

• 容易种植
• 生长周期短
• 性状对比明显
• 可自花授粉或人工杂交

3) 常见研究性状（考试重点）

| 性状 | 表现一 | 表现二 | | ---- | --- | --- | | 种子形状 | 圆 | 皱 | | 种子颜色 | 黄 | 绿 | | 花的颜色 | 紫 | 白 | | 豆荚形状 | 饱满 | 收缩 | | 植株高度 | 高 | 矮 |

4) 豌豆与潘尼特方格

豌豆性状常用于潘尼特方格题目，帮助预测后代表现。

一句话考试版总结

豌豆因性状清晰、易繁殖，被用于发现显性和隐性等遗传规律。

如果你愿意，我可以把 pea traits → alleles → Punnett squares 整理成 Science 10 中英对照练习题或互动闪卡，非常适合系统复习。

English — incomplete dominance (thorough explanation)

1) What incomplete dominance means (core idea)

Incomplete dominance is an inheritance pattern in which neither allele is completely dominant, so the heterozygous phenotype is an intermediate (blended) form of the two homozygous phenotypes.

Incomplete dominance = blending of traits in heterozygotes

2) How incomplete dominance works

• Two different alleles affect the trait
• In a heterozygous individual, both alleles partially influence the outcome
• The result looks like a mix, not one trait hiding the other

3) Classic example (Science 10 favorite): flower color

Let:

• R = red flowers
• W = white flowers

Cross: RR × WW

Offspring:

• RW → pink flowers

📌 Pink is not a new allele; it’s the intermediate phenotype.

4) Incomplete dominance in Punnett squares

Parents: RW × RW

Possible offspring:

• RR → red
• RW → pink
• RW → pink
• WW → white

Phenotype ratio: 1 red : 2 pink : 1 white

📌 Notice: phenotype ratio = genotype ratio in incomplete dominance.

5) Incomplete dominance vs other patterns (very important)

| Pattern | Heterozygous result | Example | | ------------------------ | ------------------------- | ------------------ | | Dominant–recessive | Dominant trait only | Brown eyes | | Incomplete dominance | Blended trait | Red × white → pink | | Codominance | Both traits fully visible | AB blood type |

6) Why incomplete dominance matters

Incomplete dominance:

• Explains traits that don’t follow simple dominance
• Increases visible variation in populations
• Is common in plants, animals, and humans (for some traits)

One-sentence exam summary

Incomplete dominance occurs when heterozygous individuals show an intermediate, blended phenotype.

中文 — incomplete dominance（不完全显性） 详细解释

1) 什么是不完全显性（核心概念）

不完全显性是指： 两个等位基因中没有一个完全显性，杂合体表现为中间型性状。

不完全显性 = 性状混合表现

2) 不完全显性的表现特点

• 显性不能完全压制另一等位基因
• 杂合体表现为中间状态
• 性状不是“要么这个，要么那个”

3) 经典例子（考试常考）

花的颜色：

• 红花（RR）
• 白花（WW）

杂交后：

• RW → 粉红色花

📌 粉红不是新基因，而是红和白的中间表现。

4) 潘尼特方格中的不完全显性

父母：RW × RW

后代比例：

• 1 红（RR）
• 2 粉（RW）
• 1 白（WW）

👉 表现型比例 = 基因型比例

5) 不完全显性 vs 共显性（重点区分）

| 遗传方式 | 表现结果 | | ----- | ---------- | | 不完全显性 | 中间型（混合） | | 共显性 | 两种性状同时清楚出现 |

一句话考试版总结

不完全显性指杂合体表现为两种性状的中间型。

如果你愿意，我可以把 dominant / recessive / incomplete dominance / codominance 整理成 Science 10 中英对照对比表、潘尼特方格练习或互动闪卡，非常适合系统复习与教学。

English — heterozygous (thorough explanation)

1) What heterozygous means (core idea)

Heterozygous describes a genotype in which an organism has two different alleles for the same gene.

Heterozygous = two different alleles (e.g., Aa)

Each allele comes from a different parent.

2) How heterozygous genotypes work

• Genes come in pairs (alleles)
• In a heterozygous genotype, one allele is different from the other
• Often written as one capital letter and one lowercase letter

Example:

• A = dominant allele
• a = recessive allele
• Aa = heterozygous

3) Trait expression in heterozygous individuals

In simple dominance:

• The dominant allele determines the phenotype
• The recessive allele is present but not expressed

Example:

• Genotype: Aa
• Phenotype: dominant trait

📌 The recessive allele can still be passed to offspring.

4) Heterozygous vs homozygous (important comparison)

| Term | Alleles | Example | Trait shown | | ------------------------ | --------- | ------- | ------------------ | | Heterozygous | Different | Aa | Dominant (usually) | | Homozygous dominant | Same | AA | Dominant | | Homozygous recessive | Same | aa | Recessive |

5) Heterozygous in Punnett squares (Science 10 focus)

Punnett squares show how heterozygous parents pass on alleles.

Example: Aa × Aa

Possible offspring:

• AA
• Aa
• Aa
• aa

Genotype ratio:

• 1 AA : 2 Aa : 1 aa

📌 Half the offspring are heterozygous (Aa).

6) Why heterozygous matters

Heterozygous individuals:

• Increase genetic variation
• Can be carriers of recessive traits
• Help explain why traits may skip generations
• Are important in evolution and population genetics

One-sentence exam summary

Heterozygous means having two different alleles for a gene.

中文 — heterozygous（杂合子 / 杂合） 详细解释

1) 什么是杂合（核心概念）

Heterozygous（杂合）指的是： 同一性状的两个等位基因不相同。

杂合 = 两个不同的等位基因

常见形式：

• Aa

2) 杂合基因型如何表现

• 一个等位基因来自父亲
• 一个来自母亲
• 通常是 一个显性 + 一个隐性

例子：

• Aa → 显性性状表现
• 隐性基因被“隐藏”，但仍可遗传

3) 杂合 vs 纯合（重点对比）

| 类型 | 等位基因 | 示例 | | ---- | ---- | -- | | 杂合 | 不同 | Aa | | 纯合显性 | 相同 | AA | | 纯合隐性 | 相同 | aa |

4) 潘尼特方格中的杂合

父母：Aa × Aa

后代可能为：

• AA（纯合显性）
• Aa（杂合）
• aa（纯合隐性）

比例：1 : 2 : 1

一句话考试版总结

杂合指一个性状的两个等位基因不同。

如果你愿意，我可以把 heterozygous / homozygous / dominant / recessive / Punnett squares 整理成 Science 10 中英对照闪卡或互动练习，直接用于复习或课堂教学。

English — homozygous (thorough explanation)

1) What homozygous means (core idea)

Homozygous describes a genotype in which an organism has two identical alleles for a particular gene.

Homozygous = same alleles + same alleles

Common examples:

• AA → homozygous dominant
• aa → homozygous recessive

2) Types of homozygous genotypes (Science 10 focus)

A) Homozygous dominant

• Genotype: AA
• Phenotype: dominant trait shows
• Example: Tall plant (if tall = dominant)

B) Homozygous recessive

• Genotype: aa
• Phenotype: recessive trait shows
• Example: Short plant (if short = recessive)

📌 Recessive traits only appear when the genotype is homozygous recessive.

3) Homozygous vs heterozygous (important comparison)

| Term | Alleles | Example | Trait shown | | ---------------- | --------- | -------- | ------------------------------- | | Homozygous | Same | AA or aa | Dominant (AA) or recessive (aa) | | Heterozygous | Different | Aa | Dominant |

4) Homozygous in Punnett squares

Punnett squares often show homozygous outcomes.

Example: Aa × Aa

Possible offspring genotypes:

• AA → homozygous dominant
• Aa → heterozygous
• aa → homozygous recessive

Genotype ratio:

• 1 AA : 2 Aa : 1 aa

5) Why homozygous matters

Homozygous genotypes:

• Explain why recessive traits appear
• Help predict inheritance patterns
• Are important in genetics, breeding, and evolution
• Can be linked to genetic disorders (if recessive)

One-sentence exam summary

Homozygous means having two identical alleles for a gene.

中文 — homozygous（纯合子 / 纯合） 详细解释

1) 什么是纯合（核心概念）

Homozygous（纯合）指的是： 某一性状的两个等位基因完全相同。

纯合 = 两个一样的等位基因

常见形式：

• AA（纯合显性）
• aa（纯合隐性）

2) 纯合的两种类型（考试重点）

① 纯合显性

• 基因型：AA
• 表现型：显性性状

② 纯合隐性

• 基因型：aa
• 表现型：隐性性状 📌 隐性性状只有在纯合隐性时才会出现

3) 纯合 vs 杂合（对比）

| 类型 | 等位基因 | 例子 | | -- | ---- | ----- | | 纯合 | 相同 | AA、aa | | 杂合 | 不同 | Aa |

4) 潘尼特方格中的纯合

父母：Aa × Aa

后代可能为：

• AA（纯合显性）
• Aa（杂合）
• aa（纯合隐性）

比例：1 : 2 : 1

一句话考试版总结

纯合指一个性状的两个等位基因相同。

如果你需要，我可以把 homozygous / heterozygous / dominant / recessive 整理成 Science 10 中英对照速记卡或互动练习，方便系统复习。

English — genotype (thorough explanation)

1) What genotype means (core idea)

A genotype is an organism’s genetic makeup for a specific trait — the combination of alleles it has.

Genotype = the alleles an organism carries

Genotypes are usually written as letter pairs, such as:

• AA
• Aa
• aa

These letters represent genes, not physical appearance.

2) Where genotypes come from

• One allele comes from the mother
• One allele comes from the father
• Together, they form the genotype

Genotypes are found on homologous chromosomes at the same gene location (locus).

3) Common genotype types (Science 10 focus)

Homozygous

• Both alleles are the same
• Examples: AA, aa

Heterozygous

• Alleles are different
• Example: Aa

4) Genotype vs phenotype (very important)

| Term | What it means | Example | | ------------- | ---------------- | ---------- | | Genotype | Genetic makeup | Bb | | Phenotype | Observable trait | Brown eyes |

📌 You inherit the genotype, but you observe the phenotype.

5) Genotype in Punnett squares

Punnett squares are used to predict possible genotypes of offspring.

Example: Parents: Aa × Aa

Possible genotypes:

• AA
• Aa
• Aa
• aa

Genotype ratio:

• 1 AA : 2 Aa : 1 aa

6) Why genotype matters

Genotype:

• Determines which traits can appear
• Explains why recessive traits can be hidden
• Helps predict inheritance patterns
• Is the basis of genetics and evolution

One-sentence exam summary

Genotype is the genetic makeup of an organism, represented by its allele combinations.

中文 — genotype（基因型） 详细解释

1) 什么是基因型（核心概念）

基因型（genotype）是指生物体在某一性状上所拥有的等位基因组合。

基因型 = 拥有的基因组合

常见表示方式：

• AA
• Aa
• aa

2) 基因型从哪里来

• 一个等位基因来自母亲
• 一个来自父亲
• 位于同源染色体的相同位置

3) 基因型的类型（考试重点）

纯合（homozygous）

• AA、aa

杂合（heterozygous）

• Aa

4) 基因型 vs 表现型（必考）

| 项目 | 含义 | | --- | ------- | | 基因型 | 基因组合 | | 表现型 | 实际表现的性状 |

📌 基因型决定潜力，表现型是结果。

5) 潘尼特方格中的基因型

父母：Aa × Aa

后代可能的基因型：

• AA（25%）
• Aa（50%）
• aa（25%）

一句话考试版总结

基因型是生物体所携带的等位基因组合。

如果你愿意，我可以把 allele → genotype → phenotype → Punnett square 整理成 Science 10 中英对照速记卡 / 课堂练习 / HTML 互动内容，方便你系统复习。

English — phenotype (thorough explanation)

1) What phenotype means (core idea)

A phenotype is the observable characteristics of an organism—what you can see or measure.

Phenotype = the physical expression of genes

Examples include:

• Eye color
• Height
• Blood type
• Flower color
• Ability to roll the tongue (in simple genetics examples)

2) What determines phenotype

A phenotype is shaped by two factors:

1. Genotype (the genetic makeup)
2. Environment (external conditions)

Phenotype = genotype + environment

📌 This is why people with the same genes can sometimes look different.

3) Phenotype vs genotype (must-know distinction)

| Term | Meaning | Example | | ------------- | --------------------------- | ---------- | | Genotype | The alleles an organism has | Bb | | Phenotype | The trait that appears | Brown eyes |

You inherit the genotype, but you observe the phenotype.

4) Phenotype in Punnett squares (Science 10 focus)

Punnett squares predict possible phenotypes of offspring.

Example:

• B = brown eyes (dominant)
• b = blue eyes (recessive)

Possible genotypes → phenotypes:

• BB → brown eyes
• Bb → brown eyes
• bb → blue eyes

📌 Phenotype ratios often differ from genotype ratios.

5) Environmental effects on phenotype

Even with the same genotype, environment can change phenotype:

• Height → genes + nutrition
• Skin color → genes + sunlight
• Muscle size → genes + exercise

This shows phenotype is not fixed by genes alone.

6) Why phenotype matters

Phenotypes:

• Explain variation among individuals
• Are what natural selection acts on
• Help scientists study inheritance patterns

One-sentence exam summary

Phenotype is the observable traits of an organism resulting from the interaction of genes and environment.

中文 — phenotype（表现型） 详细解释

1) 什么是表现型（核心概念）

表现型（phenotype）是指生物能够被观察到的性状或特征。

表现型 = 基因表现出来的外在结果

例如：

• 眼睛颜色
• 身高
• 血型
• 花的颜色

2) 表现型由什么决定

表现型由两部分共同决定：

1. 基因型（genotype）
2. 环境因素

表现型 = 基因型 + 环境

3) 基因型 vs 表现型（必考）

| 概念 | 含义 | | --- | -------- | | 基因型 | 拥有的等位基因 | | 表现型 | 实际表现出的性状 |

4) 潘尼特方格中的表现型

潘尼特方格用来预测：

• 后代可能出现的表现型
• 各性状出现的概率

5) 环境对表现型的影响

• 营养影响身高
• 阳光影响肤色
• 训练影响肌肉

一句话考试版总结

表现型是基因与环境共同作用下表现出来的性状。

如果你愿意，我可以把 genotype / phenotype / allele / Punnett square 整理成 Science 10 中英对照闪卡或互动练习，方便系统复习。

English — recessive (thorough explanation)

1) What recessive means (core idea)

Recessive describes an allele whose effect is hidden when a dominant allele is present. A recessive trait is expressed only when both alleles are recessive.

Recessive = shows only when two recessive alleles are present

2) How recessive alleles work

• Each individual has two alleles for a gene (one from each parent)
• If at least one dominant allele is present, the dominant trait appears
• The recessive trait appears only in homozygous recessive individuals

📌 Genetics notation:

• A = dominant allele
• a = recessive allele

| Genotype | Trait shown | | -------- | --------------------------- | | AA | Dominant | | Aa | Dominant (recessive hidden) | | aa | Recessive |

3) Examples of recessive traits

Common textbook examples:

• Blue eyes (recessive to brown)
• Attached earlobes
• Certain genetic disorders (e.g., cystic fibrosis)

📌 A person can carry a recessive allele without showing the trait.

4) Recessive traits in Punnett squares (Science 10 focus)

Punnett squares help predict recessive traits.

Example: Parents: Aa × Aa

Possible offspring:

• AA
• Aa
• Aa
• aa

👉 25% chance of showing the recessive trait (aa)

5) Recessive vs dominant (key contrast)

| Feature | Dominant | Recessive | | ----------------------- | ------------------- | -------------------- | | Expression | Shows with 1 allele | Shows with 2 alleles | | Hidden by other allele? | No | Yes | | Written as | Capital letter | Lowercase letter |

6) Why recessive traits matter

Recessive traits:

• Explain why traits can skip generations
• Help identify carriers
• Are important in genetic counseling
• Increase genetic variation in populations

One-sentence exam summary

A recessive allele is expressed only when two copies are present and is hidden by a dominant allele.

中文 — recessive（隐性） 详细解释

1) 什么是隐性（核心概念）

隐性（recessive）指的是一种等位基因，当与显性等位基因同时存在时，不会表现出来。

隐性 = 只有在两个隐性等位基因同时存在时才表现

2) 隐性等位基因如何表现

• 每个性状由 两个等位基因控制
• 只要有一个显性等位基因，显性性状就出现
• 隐性性状必须是纯合隐性（aa）才会表现

3) 隐性性状的例子

• 蓝色眼睛
• 连着的耳垂
• 某些遗传疾病（如囊性纤维化）

📌 携带者：有隐性基因，但不表现性状。

4) 潘尼特方格中的隐性（考试重点）

父母：Aa × Aa

结果：

• 25% aa（表现隐性性状）
• 50% Aa（携带者）
• 25% AA

5) 隐性 vs 显性（对比）

| 项目 | 显性 | 隐性 | | ---- | ------ | ---- | | 表现条件 | 有一个就表现 | 必须两个 | | 书写方式 | 大写字母 | 小写字母 |

一句话考试版总结

隐性性状只有在两个隐性等位基因同时存在时才会表现。

如果你需要，我可以把 dominant / recessive / codominance / incomplete dominance 整理成 Science 10 中英对照速记表或练习题，帮助你快速区分考点。

English — codominance (thorough explanation)

1) What codominance means (core idea)

Codominance is a pattern of inheritance in which both alleles in a heterozygous individual are fully and equally expressed.

Codominance = both alleles show at the same time

Neither allele is dominant or recessive over the other.

2) How codominance looks (key idea)

In codominance:

• You do not get a blend
• You see both traits clearly and separately

📌 This is different from incomplete dominance, where traits blend.

3) Classic examples of codominance (Science 10 favorites)

A) Roan cattle

• Red allele + White allele
• Result: Roan coat with both red hairs and white hairs
• Not pink → red and white are both visible

B) Human blood type (AB)

• Alleles: IA and IB
• Genotype: IAIB
• Phenotype: AB blood type
• Both A and B antigens appear on red blood cells

4) Codominance vs incomplete dominance (very important)

| Feature | Codominance | Incomplete Dominance | | ----------------- | -------------------- | -------------------------- | | Allele expression | Both fully expressed | Blended | | Appearance | Both traits visible | Mixed/intermediate | | Example | AB blood type | Pink flowers (red × white) |

📌 AB blood type = codominance 📌 Pink flowers = incomplete dominance

5) Codominance in Punnett squares

Codominance still uses Punnett squares, but:

• Heterozygous offspring show both traits
• No allele “hides” the other

Example:

• Alleles: R (red), W (white)
• RW → red + white hairs

6) Why codominance matters

Codominance:

• Explains traits that don’t follow simple dominant/recessive rules
• Increases visible genetic variation
• Is important in medical genetics (blood transfusions)

One-sentence exam summary

Codominance occurs when both alleles in a heterozygous individual are fully expressed at the same time.

中文 — codominance（共显性） 详细解释

1) 什么是共显性（核心概念）

共显性（codominance）指的是： 两个不同的等位基因在杂合体中都会完全表现出来。

共显性 = 两个等位基因同时、完整地表现

2) 共显性的表现特点

• 不会混合
• 两种性状同时清楚可见

📌 和不完全显性不同，共显性没有中间型。

3) 常见例子（考试常考）

A) 花牛（roan cattle）

• 红色等位基因 + 白色等位基因
• 结果：红毛和白毛同时存在

B) 人类 AB 血型

• 等位基因：IA 和 IB
• 基因型：IAIB
• 表现型：AB 型血
• A 抗原和 B 抗原同时存在

4) 共显性 vs 不完全显性（重点对比）

| 特点 | 共显性 | 不完全显性 | | -- | ------- | ----- | | 表现 | 两种性状都出现 | 性状混合 | | 结果 | 同时可见 | 中间型 | | 例子 | AB 血型 | 红×白→粉 |

5) 共显性在潘尼特方格中的体现

• 杂合体表现两种性状
• 没有“显性压制隐性”

一句话考试版总结

共显性是指杂合体中两个等位基因同时完全表现的遗传方式。

如果你愿意，我可以把 dominance / incomplete dominance / codominance 整理成 Science 10 中英对照表或互动练习题，非常适合考试快速区分。

English — alleles (thorough explanation)

1) What alleles are (core idea)

Alleles are different versions of the same gene. They control variations of a trait, such as eye color or flower color.

Allele = one version of a gene

Each gene can have two or more alleles, but an individual organism usually carries two alleles per gene (one from each parent).

2) Where alleles are found

• Genes are located on chromosomes
• Alleles sit at the same position (locus) on homologous chromosomes
• One allele comes from the mother
• One allele comes from the father

📌 This is why offspring show traits from both parents.

3) Example of alleles (simple)

Trait: Seed color

• Y = yellow
• y = green

Possible allele combinations:

• YY
• Yy
• yy

These combinations affect the trait that appears.

4) Dominant vs recessive alleles (Science 10 focus)

Dominant allele

• Shown with a capital letter (A)
• Expressed if at least one copy is present

Recessive allele

• Shown with a lowercase letter (a)
• Expressed only if two copies are present

📌 Example:

• Aa → dominant trait shows
• aa → recessive trait shows

5) Alleles, genotype, and phenotype (key relationship)

| Term | Meaning | Example | | --------- | ------------------ | ---------- | | Allele | Version of a gene | A or a | | Genotype | Allele combination | Aa | | Phenotype | Physical trait | Brown eyes |

Alleles determine the genotype, which determines the phenotype.

6) Alleles in Punnett squares

Punnett squares:

• Show how alleles from parents combine
• Predict possible offspring genotypes
• Estimate trait probabilities

📌 Example: Parents: Aa × Aa

• Possible offspring: AA, Aa, Aa, aa

7) Why alleles are important

Alleles:

• Explain variation within a species
• Help predict inheritance patterns
• Are the basis of genetics and evolution
• Allow populations to adapt over time

One-sentence exam summary

Alleles are different versions of the same gene that determine variations in traits.

中文 — alleles（等位基因） 详细解释

1) 什么是等位基因（核心概念）

等位基因（alleles）是指同一基因的不同版本，决定同一性状的不同表现。

等位基因 = 同一基因的不同形式

2) 等位基因在哪里

• 基因位于染色体上
• 等位基因位于同源染色体的相同位置
• 一个来自母亲，一个来自父亲

3) 等位基因举例

性状：豌豆高度

• T = 高
• t = 矮

组合可能是：

• TT
• Tt
• tt

4) 显性与隐性等位基因（必考）

• 显性等位基因：只要有一个就会表现
• 隐性等位基因：必须两个都有才表现

📌 Tt → 显性性状 📌 tt → 隐性性状

5) 等位基因与性状的关系

• 等位基因 → 基因型
• 基因型 → 表现型

一句话考试版总结

等位基因是控制同一性状的不同基因形式。

如果你愿意，我可以把 alleles → genotype → phenotype → Punnett squares 整理成 Science 10 中英对照闪卡或互动练习，直接用于复习或教学。

English — traits (thorough explanation)

1) What traits are (core idea)

Traits are characteristics or features of an organism. They describe how an organism looks, behaves, or functions.

Trait = a characteristic of a living thing

Traits can be:

• Inherited (passed down from parents)
• Influenced by the environment
• Or a combination of both

2) Types of traits

A) Inherited (genetic) traits

These traits are controlled by genes and passed from parents to offspring.

Examples:

• Eye color
• Hair color and texture
• Blood type
• Natural height potential

📌 These traits are present from birth.

B) Acquired (environmental) traits

These traits develop due to life experiences or environment.

Examples:

• Suntan
• Muscle strength from exercise
• Scars
• Language spoken

📌 These traits are not inherited genetically.

C) Traits influenced by both genes and environment

Many traits result from both heredity and environment.

Examples:

• Height (genes + nutrition)
• Intelligence (genes + education)
• Athletic ability (genes + training)

3) Traits in genetics (Science 10 focus)

In genetics, traits are:

• Controlled by genes
• Each gene may have different alleles
• Alleles can be dominant or recessive

📌 Example:

• Brown eyes (dominant)
• Blue eyes (recessive)

Punnett squares are used to predict traits in offspring.

4) Genotype vs phenotype (important distinction)

| Term | Meaning | Example | | --------- | ------------------- | ---------- | | Genotype | Genetic makeup | Bb | | Phenotype | Physical expression | Brown eyes |

📌 Traits are what you see (phenotype), based on genes (genotype).

5) Why traits matter

Traits:

• Explain similarities and differences between organisms
• Help scientists study inheritance
• Are the basis of natural selection and evolution

One-sentence exam summary

Traits are characteristics of organisms that can be inherited, acquired, or influenced by both genes and environment.

中文 — traits（性状 / 特征） 详细解释

1) 什么是性状（核心概念）

性状（traits）是指生物表现出来的特征或特点。

性状 = 生物的特征

2) 性状的类型

① 遗传性状

由基因决定，从父母传给子女。

例子：

• 眼睛颜色
• 头发颜色
• 血型

② 获得性状

由环境或经历造成。

例子：

• 晒黑
• 肌肉增强
• 疤痕

③ 遗传 + 环境共同影响

• 身高
• 学习能力
• 运动能力

3) 遗传学中的性状（考试重点）

• 性状由基因控制
• 基因有不同等位基因
• 等位基因有显性和隐性

4) 基因型 vs 表现型

| 概念 | 含义 | | --- | ---- | | 基因型 | 基因组合 | | 表现型 | 外在性状 |

一句话考试版总结

性状是生物的特征，由遗传和环境共同决定。

如果你需要，我可以把 traits / inherited traits / acquired traits / Punnett squares 做成 Science 10 中英对照闪卡或课堂练习题，直接用于教学或复习。

English — Punnett squares (thorough explanation)

1) What Punnett squares are (core idea)

Punnett squares are simple diagrams used in genetics to predict the possible genetic outcomes of offspring from two parents.

Punnett square = a tool to predict inherited traits

They help scientists and students see:

• Possible genotypes (gene combinations)
• Possible phenotypes (physical traits)
• Probability of each outcome

2) Why Punnett squares are used

Punnett squares are used to:

• Understand hereditary inheritance
• Predict offspring traits
• Explain why siblings can look different
• Show how dominant and recessive genes work

They do not guarantee results — they show likelihood.

3) Key terms you must know (Science 10)

| Term | Meaning | | --------- | -------------------------------------------- | | Gene | Section of DNA that controls a trait | | Allele | Different forms of a gene (e.g., A or a) | | Dominant | Masks another allele (A) | | Recessive | Only shows if both alleles are recessive (a) | | Genotype | Genetic makeup (AA, Aa, aa) | | Phenotype | Physical appearance (tall, short, etc.) |

4) How a Punnett square works (step by step)

Example: One trait (monohybrid cross)

Trait: Plant height

• T = tall (dominant)
• t = short (recessive)

Parents: Tt × Tt

Step 1: Draw a 2×2 square Step 2: Put one parent’s alleles across the top (T, t) Step 3: Put the other parent’s alleles down the side (T, t) Step 4: Fill in the boxes

Resulting genotypes:

• TT
• Tt
• Tt
• tt

5) Reading the results

Genotype ratio

• 1 TT : 2 Tt : 1 tt

Phenotype ratio

• 3 tall : 1 short

📌 Even though only 1 box is tt, that still means a 25% chance of short offspring.

6) Types of Punnett squares

A) Monohybrid cross

• One trait
• 2×2 square
• Most common in Science 10

B) Dihybrid cross (advanced)

• Two traits at once
• 4×4 square
• Shows independent assortment

7) Limits of Punnett squares

Punnett squares:

• Assume genes assort randomly
• Do not account for environment
• Work best for simple traits

One-sentence exam summary

Punnett squares are diagrams used to predict the probability of genetic traits in offspring.

中文 — Punnett squares（潘尼特方格） 详细解释

1) 什么是潘尼特方格（核心概念）

潘尼特方格是一种遗传学工具，用来预测父母基因组合在后代中可能出现的结果。

潘尼特方格 = 预测遗传结果的表格

2) 为什么要用潘尼特方格

潘尼特方格可以帮助我们：

• 理解遗传规律
• 预测后代性状
• 解释兄弟姐妹的差异
• 学习显性与隐性

3) 必须掌握的词汇（考试重点）

| 英文 | 中文 | | --------- | ---- | | Gene | 基因 | | Allele | 等位基因 | | Dominant | 显性 | | Recessive | 隐性 | | Genotype | 基因型 | | Phenotype | 表现型 |

4) 潘尼特方格如何使用（一步一步）

例子：豌豆高度

• T = 高（显性）
• t = 矮（隐性）

父母：Tt × Tt

填表后得到：

• TT
• Tt
• Tt
• tt

5) 结果解读

基因型比例

• 1 TT : 2 Tt : 1 tt

表现型比例

• 3 高 : 1 矮

📌 这表示： 25% 矮，75% 高（概率，不是保证）

6) 潘尼特方格的类型

• 单性状杂交（2×2）
• 双性状杂交（4×4，高阶内容）

一句话考试版总结

潘尼特方格用于预测遗传性状在后代中出现的概率。

如果你愿意，我可以把 Punnett square → allele → genotype → phenotype 整理成 Science 10 中英对照闪卡 / 课堂练习 / HTML 互动方格，直接给学生用。

English — complementary bases (thorough explanation)

1) What complementary bases means (core idea)

Complementary bases are pairs of nitrogenous bases that fit together in a specific way in DNA (and RNA).

Complementary bases = bases that pair in a fixed, matching pattern

They are called complementary because:

• One base always matches with only one other base
• The pairing is predictable and consistent

2) The complementary base-pairing rules (must know)

In DNA:

• Adenine (A) pairs with Thymine (T)
• Cytosine (C) pairs with Guanine (G)

In RNA:

• Adenine (A) pairs with Uracil (U)
• Cytosine (C) pairs with Guanine (G)

📌 These rules never change.

3) Why these bases pair together

Complementary pairing happens because of:

• Shape → bases fit together like puzzle pieces
• Hydrogen bonding → specific bases can form hydrogen bonds with each other

Details:

• A–T form 2 hydrogen bonds
• C–G form 3 hydrogen bonds (stronger)

This keeps DNA:

• Stable
• Uniform in width

4) Complementary bases in DNA structure

DNA looks like a twisted ladder:

• The sides → sugar–phosphate backbones
• The rungs → complementary base pairs

Each rung is:

• One base from one strand
• Its complementary base from the other strand

5) Why complementary bases are essential (Science 10 focus)

A) DNA replication

• DNA strands separate
• Each strand uses complementary bases to build a new strand
• Result: two identical DNA molecules

B) Transcription (DNA → RNA)

• RNA is built using complementary base pairing
• Ensures accurate genetic instructions

C) Genetic accuracy

• Complementary pairing prevents many errors
• Maintains stable inheritance of traits

6) Example (exam-style)

If one DNA strand is:

A T G C C A

The complementary strand is:

T A C G G T

One-sentence exam summary

Complementary bases are specific base pairs (A–T and C–G) that hold DNA strands together and allow accurate replication.

中文 — complementary bases（互补碱基） 详细解释

1) 什么是互补碱基（核心概念）

互补碱基是指在 DNA（或 RNA）中，只能按照固定规则配对的碱基。

互补碱基 = 能一一对应配对的碱基

2) 互补配对规则（必背）

DNA 中：

• A（腺嘌呤） ↔ T（胸腺嘧啶）
• C（胞嘧啶） ↔ G（鸟嘌呤）

RNA 中：

• A ↔ U（尿嘧啶）
• C ↔ G

3) 为什么叫“互补”

互补的原因是：

• 形状匹配
• 氢键数量固定

具体来说：

• A–T：2 条氢键
• C–G：3 条氢键（更牢固）

这保证了 DNA 结构：

• 稳定
• 宽度一致

4) 互补碱基在 DNA 中的位置

DNA 像一把梯子：

• 两侧：糖—磷酸骨架
• 横档：互补碱基对

每一个“横档”就是一对互补碱基。

5) 互补碱基为什么重要（考试重点）

① DNA 复制

• 旧链作模板
• 通过互补配对生成新链
• 遗传信息准确复制

② 转录（DNA → RNA）

• RNA 按互补规则合成
• 遗传信息得以表达

③ 遗传稳定性

• 减少错误
• 保证性状正确遗传

6) 考试例题示范

如果 DNA 一条链是：

A T G C

互补链是：

T A C G

一句话考试版总结

互补碱基是 DNA 中按照 A–T、C–G 规则配对的碱基，保证遗传信息准确复制。

如果你愿意，我可以把 complementary bases → DNA replication → transcription 做成 Science 10 中英对照流程图 / 互动闪卡，直接用于课堂或复习。

English — rung (thorough explanation)

1) What “rung” means (core idea)

A rung is a horizontal step or bar that connects the two sides of a ladder.

Rung = one step of a ladder

You climb a ladder by stepping on its rungs.

2) “Rung” as a metaphor in biology (Science 10 focus)

In biology, rung is often used as a comparison (metaphor) when explaining DNA structure.

• DNA is often described as a twisted ladder
• The sides of the ladder → sugar–phosphate backbones
• The rungs of the ladder → paired nitrogenous bases

📌 Each DNA rung is made of a base pair:

• A–T (adenine–thymine)
• C–G (cytosine–guanine)

These base pairs are held together by hydrogen bonds.

3) What makes up a DNA “rung”

Each rung consists of:

• Two nitrogenous bases
• Joined by hydrogen bonds
• One base from each DNA strand

Example:

One rung = A on one strand + T on the other strand

4) Why the “rung” idea helps understanding

The ladder model helps students visualize that:

• DNA has two strands
• The strands are connected at regular intervals
• The order of rungs carries genetic information

📌 The sequence of rungs = genetic code.

5) Everyday uses of “rung”

• Ladder rung
• A rung on a career ladder (metaphor)
• A rung in a rope ladder

One-sentence exam summary

A rung is a horizontal step of a ladder; in DNA, rungs represent paired nitrogenous bases connecting the two strands.

中文 — rung（梯级 / 横档） 详细解释

1) “rung”的基本含义

Rung 指的是梯子上的横档或踏板，用来踩踏和攀爬。

Rung = 梯子的一格横档

2) 生物学中的 rung（DNA 比喻，重点）

在生物学中，DNA 常被比作一把梯子：

• 梯子的两侧 → 糖—磷酸骨架
• 梯子的横档（rungs）→ 碱基对

📌 每一个 DNA 的“rung”由一对碱基组成：

• A–T
• C–G

3) DNA 横档的作用

• 把两条 DNA 链连接在一起
• 保持双螺旋结构稳定
• 横档的排列顺序储存遗传信息

一句话考试版总结

Rung 指梯子的横档，在 DNA 中用来比喻连接两条链的碱基对。

如果你需要，我可以把 ladder model → rung → base pair → hydrogen bond 做成 Science 10 中英对照图解或互动闪卡，非常适合课堂讲解与复习。

English — strands (thorough explanation)

1) What “strands” means (core idea)

Strands are long, thin lines or threads of material. In science, the word is often used to describe structures that are stretched out rather than clumped or round.

Strand = a long, thin piece of something

2) “Strands” in biology (Science 10 focus)

A) DNA strands

DNA is made of two strands that twist together to form a double helix.

• Each strand is a long chain of nucleotides
• The two strands are held together by base pairing
• The strands run in opposite directions (antiparallel)

📌 One strand is not enough for stable DNA → two strands are needed.

B) RNA strand

RNA usually has only one strand.

• Single-stranded structure
• Made of nucleotides like DNA
• Used to carry and translate genetic information

📌 This is why RNA is more flexible but less stable than DNA.

C) Protein strands (fibers)

Some proteins form strand-like fibers, such as:

• Muscle proteins
• Collagen fibers
• Keratin in hair and nails

3) “Strands” outside biology (quick examples)

• Hair strands → individual hairs
• Fiber strands → threads in fabric or rope
• Data strands → sequences of information (metaphorical use)

4) Strand vs chain vs helix (common confusion)

| Term | Meaning | | ------------ | ---------------------------- | | Strand | One long, thin line | | Chain | Many units linked together | | Double helix | Two strands twisted together |

📌 In DNA:

• Each strand is a chain
• Two strands form a double helix

5) Why strands matter in genetics

• The order of bases along a strand carries information
• Complementary strands allow accurate copying
• Strand separation is essential for replication and transcription

One-sentence exam summary

Strands are long, thin chains; DNA has two strands, while RNA usually has one.

中文 — strands（链 / 丝状结构） 详细解释

1) “strands”的基本含义

Strands 指的是 细长、线状的结构。

Strand = 一条细长的链或丝

2) 生物学中的 strands（重点）

A) DNA 链

DNA 由 两条链（两条 strand）组成：

• 每条链由核苷酸连接而成
• 两条链通过碱基配对结合
• 共同形成 双螺旋结构

B) RNA 链

RNA 通常是 单链结构：

• 只有一条 strand
• 用于传递和执行遗传信息

C) 蛋白质纤维

某些蛋白质呈丝状结构：

• 肌肉纤维
• 胶原蛋白
• 角蛋白（头发）

3) strand 与相关词的区别

| 英文 | 中文 | 说明 | | ------------ | --- | ------- | | strand | 链 | 一条细长结构 | | chain | 链条 | 多个单位连接 | | double helix | 双螺旋 | 两条链扭在一起 |

一句话考试版总结

DNA 是双链结构，RNA 通常是单链结构。

如果你愿意，我可以把 strand → nucleotide → base pairing → double helix 做成 Science 10 中英对照概念图或互动闪卡，直接用于复习或教学。

English — ribonucleic (thorough explanation)

1) What ribonucleic means (core idea)

Ribonucleic means related to RNA (ribonucleic acid). The word is most commonly seen in ribonucleic acid, abbreviated as RNA.

Ribonucleic = having to do with RNA

2) Why it’s called “ribonucleic”

The name comes from its components:

• Ribo- → ribose sugar
• -nucleic → found in the nucleus (or related to genetic material)

So:

Ribonucleic acid = nucleic acid containing ribose sugar

3) What ribonucleic acid (RNA) is

RNA is a molecule that:

• Carries genetic instructions
• Helps make proteins
• Works closely with DNA

Unlike DNA, RNA is usually:

• Single-stranded
• Shorter
• Less stable

4) Structure of ribonucleic acid (exam focus)

Each RNA nucleotide has:

1. Phosphate group
2. Ribose sugar
3. Nitrogenous base

RNA bases are:

• Adenine (A)
• Uracil (U) ← replaces thymine
• Cytosine (C)
• Guanine (G)

📌 The presence of ribose sugar is what makes RNA “ribo”-nucleic.

5) Main types of ribonucleic acid

mRNA (messenger RNA)

• Carries instructions from DNA to ribosomes

tRNA (transfer RNA)

• Brings amino acids to build proteins

rRNA (ribosomal RNA)

• Forms part of the ribosome

All of these are ribonucleic acids.

6) Ribonucleic vs deoxyribonucleic (RNA vs DNA)

| Feature | Ribonucleic (RNA) | Deoxyribonucleic (DNA) | | --------- | ----------------- | ---------------------- | | Sugar | Ribose | Deoxyribose | | Strands | Single | Double | | Bases | A, U, C, G | A, T, C, G | | Function | Protein synthesis | Store genetic info | | Stability | Lower | Higher |

7) Why ribonucleic acid is important

Without ribonucleic acid:

• Genetic information could not be used
• Proteins could not be made
• Cells could not function properly

DNA stores information; ribonucleic acid uses it

One-sentence exam summary

Ribonucleic refers to RNA, a nucleic acid containing ribose sugar that helps convert genetic information into proteins.

中文 — ribonucleic（核糖核酸的） 详细解释

1) “ribonucleic”的基本含义

Ribonucleic 指的是与 RNA（核糖核酸）有关的。

Ribonucleic = 核糖核酸的

2) 为什么叫“核糖核酸”

• ribo-：核糖
• nucleic：核酸 / 遗传物质

RNA 是含有核糖的核酸。

3) RNA 是什么

RNA（核糖核酸）是：

• 遗传信息的“执行者”
• 参与蛋白质合成
• 帮助细胞工作的重要分子

4) RNA 的结构（考试重点）

RNA 的每个核苷酸包括：

1. 磷酸基团
2. 核糖
3. 含氮碱基

RNA 的碱基是：

• A、U、C、G

5) RNA 的主要类型

• 信使 RNA（mRNA）：传递指令
• 转运 RNA（tRNA）：搬运氨基酸
• 核糖体 RNA（rRNA）：构成核糖体

6) RNA 与 DNA 的区别（常考）

| 项目 | RNA | DNA | | -- | ----- | ------ | | 糖 | 核糖 | 脱氧核糖 | | 结构 | 单链 | 双链 | | 功能 | 蛋白质合成 | 储存遗传信息 |

一句话考试版总结

Ribonucleic 指的是核糖核酸（RNA），一种含核糖、参与蛋白质合成的核酸。

如果你愿意，我可以把 ribonucleic / deoxyribonucleic / nucleotide / base 做成 Science 10 中英对照概念链或互动闪卡，方便你系统复习。

English — Thymine (T) (thorough explanation)

1) What thymine is (core idea)

Thymine is a nitrogenous base found only in DNA. It is one of the four bases that make up the DNA genetic code.

Thymine = a DNA base that pairs with adenine

2) Where thymine is found

• DNA ✅
• RNA ❌ (RNA uses uracil instead)

Each thymine base is part of a nucleotide, attached to:

• Deoxyribose sugar
• Phosphate group

3) Thymine’s base-pairing rule (exam essential)

In DNA:

• Thymine (T) pairs with Adenine (A)
• Held together by 2 hydrogen bonds

This specific pairing:

• Keeps DNA strands aligned
• Allows accurate DNA replication

4) Chemical group of thymine

Thymine belongs to the pyrimidines, which:

• Have a single-ring structure
• Are smaller than purines

Pyrimidines: Cytosine (C), Thymine (T), Uracil (U) Purines: Adenine (A), Guanine (G)

Purine–pyrimidine pairing keeps the DNA double helix a constant width.

5) Role of thymine in DNA

• Thymine helps store genetic information
• The order of T bases (with A, C, G) determines genes
• Correct T–A pairing ensures genetic stability

A mistake involving thymine (a mutation) can:

• Change a gene
• Alter protein structure
• Affect traits

6) Thymine vs uracil (common exam comparison)

| Feature | Thymine (T) | Uracil (U) | | ---------- | ----------- | ----------- | | Found in | DNA | RNA | | Pairs with | Adenine | Adenine | | Stability | More stable | Less stable |

📌 Thymine makes DNA more stable for long-term information storage.

One-sentence exam summary

Thymine is a pyrimidine nitrogenous base found only in DNA that pairs with adenine using two hydrogen bonds.

中文 — Thymine（胸腺嘧啶，T） 详细解释

1) 什么是胸腺嘧啶（核心概念）

胸腺嘧啶（Thymine，T）是一种只存在于 DNA 中的含氮碱基，是 DNA 遗传信息的重要组成部分。

胸腺嘧啶 = DNA 中与腺嘌呤配对的碱基

2) 胸腺嘧啶出现在哪里

• DNA 中有
• RNA 中没有（RNA 用的是尿嘧啶 U）

3) 胸腺嘧啶的配对规则（必考）

DNA 中：

• T ↔ A
• 通过 2 条氢键连接

这种精确配对保证 DNA 复制准确。

4) 胸腺嘧啶的类别

胸腺嘧啶属于 嘧啶（pyrimidine）：

• 单环结构
• 分子较小

5) 胸腺嘧啶的作用

• 参与遗传信息储存
• 确保 DNA 双螺旋结构稳定
• 维持遗传信息长期保存

6) 胸腺嘧啶 vs 尿嘧啶（常考对比）

| 项目 | 胸腺嘧啶 | 尿嘧啶 | | ---- | ---- | --- | | 所在分子 | DNA | RNA | | 配对对象 | 腺嘌呤 | 腺嘌呤 | | 稳定性 | 更高 | 较低 |

一句话考试版总结

胸腺嘧啶是 DNA 中与腺嘌呤配对、具有两条氢键的嘧啶碱基。

如果你需要，我可以把 A–T vs C–G 的稳定性比较或把 四种 DNA 碱基整理成 Science 10 中英对照闪卡 / 互动图表，方便系统复习与教学。

English — Guanine (G) (thorough explanation)

1) What guanine is (core idea)

Guanine is a nitrogenous base found in DNA and RNA. It is one of the four bases that make up the genetic code.

Guanine = a nitrogen-containing base that stores genetic information

2) Where guanine is found

Guanine appears in:

• DNA
• RNA

It is always part of a nucleotide, attached to:

• A sugar (deoxyribose in DNA, ribose in RNA)
• A phosphate group

3) Guanine’s base-pairing rule (exam essential)

In DNA:

• Guanine (G) pairs with Cytosine (C)
• They are held together by 3 hydrogen bonds

In RNA:

• Guanine (G) pairs with Cytosine (C)

📌 Because there are three hydrogen bonds, G–C pairs are stronger and more stable than A–T pairs.

4) Guanine’s chemical group

Guanine belongs to the purines, which:

• Have a double-ring structure
• Are larger than pyrimidines

Purines: Adenine (A), Guanine (G) Pyrimidines: Cytosine (C), Thymine (T), Uracil (U)

This size matching (purine–pyrimidine) keeps the DNA double helix uniform in width.

5) Role of guanine in DNA

In DNA:

• Guanine attaches to the sugar to form a nucleotide
• The sequence of G (with A, T, C) determines genetic instructions
• Accurate G–C pairing ensures correct DNA replication

Changes involving guanine can cause mutations, potentially affecting proteins and traits.

6) Guanine and DNA stability

• Regions with many G–C pairs are more thermally stable
• Such regions often occur in important regulatory areas of DNA

One-sentence exam summary

Guanine is a purine nitrogenous base that pairs with cytosine using three hydrogen bonds in DNA and RNA.

中文 — Guanine（鸟嘌呤，G） 详细解释

1) 什么是鸟嘌呤（核心概念）

鸟嘌呤（Guanine，G）是一种存在于 DNA 和 RNA 中的含氮碱基，是遗传信息的重要组成部分。

鸟嘌呤 = DNA / RNA 中的遗传“字母”之一

2) 鸟嘌呤出现在哪里

鸟嘌呤存在于：

• DNA
• RNA

它与：

• 糖
• 磷酸基团 一起组成 核苷酸。

3) 鸟嘌呤的配对规则（必考）

DNA 中：

• G ↔ C
• 通过 3 条氢键连接

RNA 中：

• G ↔ C

📌 三条氢键使 G–C 配对更加牢固。

4) 鸟嘌呤的类别

鸟嘌呤属于 嘌呤（purine）：

• 双环结构
• 分子较大

对比：

• 嘌呤：A、G
• 嘧啶：C、T、U

5) 鸟嘌呤在 DNA 中的作用

• 与脱氧核糖结合形成核苷酸
• 与胞嘧啶精确配对
• 确保 DNA 复制的准确性

碱基变化可能导致突变。

一句话考试版总结

鸟嘌呤是 DNA 和 RNA 中与胞嘧啶配对、具有三条氢键的嘌呤碱基。

如果你需要，我可以把 A–T vs C–G 的稳定性对比、或把四种碱基做成 Science 10 中英对照闪卡 / 互动图解，直接用于复习或教学。

English — Cytosine (C) (thorough explanation)

1) What cytosine is (core idea)

Cytosine is a nitrogenous base found in DNA and RNA. It is one of the four main bases that make up the genetic code.

Cytosine = a nitrogen-containing base that helps store genetic information

2) Where cytosine is found

Cytosine occurs in:

• DNA
• RNA

It is always part of a nucleotide, attached to:

• A sugar (deoxyribose in DNA, ribose in RNA)
• A phosphate group

3) Cytosine’s base-pairing rule (exam essential)

In DNA:

• Cytosine (C) pairs with Guanine (G)
• They are held together by 3 hydrogen bonds

In RNA:

• Cytosine (C) pairs with Guanine (G)

📌 The three hydrogen bonds make the C–G pair stronger than the A–T pair.

4) Cytosine’s chemical group

Cytosine belongs to the pyrimidines, which:

• Have a single-ring structure
• Are smaller than purines

Purines (double ring):

• Adenine (A)
• Guanine (G)

Pyrimidines (single ring):

• Cytosine (C)
• Thymine (T)
• Uracil (U)

This size matching keeps the DNA double helix uniform in width.

5) Role of cytosine in DNA

In DNA:

• Cytosine attaches to the sugar to form a nucleotide
• The order of cytosine (with A, T, G) determines genetic instructions
• Accurate C–G pairing ensures correct DNA replication

A change in cytosine (mutation) can:

• Alter genes
• Affect proteins
• Change traits

6) Cytosine and genetic stability

Because C–G pairs have three hydrogen bonds:

• Regions rich in C and G are more stable
• They often occur in important regulatory regions of DNA

One-sentence exam summary

Cytosine is a pyrimidine nitrogenous base that pairs with guanine using three hydrogen bonds in DNA and RNA.

中文 — Cytosine（胞嘧啶，C） 详细解释

1) 什么是胞嘧啶（核心概念）

胞嘧啶（Cytosine，C）是一种存在于 DNA 和 RNA 中的含氮碱基，是遗传信息的基本组成单位之一。

胞嘧啶 = DNA / RNA 中的重要碱基

2) 胞嘧啶出现在哪里

胞嘧啶存在于：

• DNA
• RNA

它与：

• 糖（DNA 中是脱氧核糖）
• 磷酸基团 一起构成核苷酸。

3) 胞嘧啶的配对规则（必考）

DNA 中：

• C ↔ G
• 通过 3 条氢键连接

RNA 中：

• C ↔ G

📌 三条氢键使 C–G 配对更牢固。

4) 胞嘧啶的类别

胞嘧啶属于 嘧啶（pyrimidine）：

• 单环结构
• 分子较小

嘌呤（双环）：A、G 嘧啶（单环）：C、T、U

5) 胞嘧啶在 DNA 中的作用

• 与脱氧核糖结合形成核苷酸
• 与鸟嘌呤精确配对
• 保证 DNA 复制的准确性

碱基变化可能导致突变。

6) 一句话考试版总结

胞嘧啶是 DNA 和 RNA 中与鸟嘌呤配对的嘧啶碱基，具有三条氢键。

如果你愿意，我可以把 Adenine / Thymine / Cytosine / Guanine 做成 Science 10 中英对照碱基配对表或互动闪卡，非常适合系统复习与教学。

English — Adenine (A) (thorough explanation)

1) What adenine is (core idea)

Adenine is a nitrogenous base found in DNA and RNA. It is one of the letters of the genetic code.

Adenine = a nitrogen-containing base that carries genetic information

2) Where adenine is found

Adenine appears in several key biological molecules:

• DNA → pairs with thymine (T)
• RNA → pairs with uracil (U)
• ATP → part of the energy molecule used by cells

3) Adenine’s base-pairing rules (exam essential)

In DNA:

• A pairs with T
• Held together by 2 hydrogen bonds

In RNA:

• A pairs with U

These pairing rules ensure accurate DNA replication and correct protein synthesis.

4) Adenine’s chemical group

Adenine belongs to the purines, which:

• Have a double-ring structure
• Are larger than pyrimidines

Purines: Adenine (A), Guanine (G) Pyrimidines: Cytosine (C), Thymine (T), Uracil (U)

This size difference explains why:

• Purine always pairs with pyrimidine
• DNA maintains a uniform width

5) Role of adenine in DNA

In DNA:

• Adenine attaches to deoxyribose sugar
• Becomes part of a nucleotide
• The sequence of adenine (with other bases) determines genetic instructions

Changing adenine’s position can:

• Alter genes
• Cause mutations
• Affect traits

6) Adenine in energy (ATP connection)

Adenine is part of ATP (adenosine triphosphate):

• Adenine + ribose = adenosine
• Adenosine + 3 phosphates = ATP

ATP provides energy for:

• Muscle contraction
• Active transport
• Chemical reactions

One-sentence exam summary

Adenine is a purine nitrogenous base that pairs with thymine in DNA and with uracil in RNA.

中文 — Adenine（腺嘌呤，A） 详细解释

1) 什么是腺嘌呤（核心概念）

腺嘌呤（Adenine，A）是一种含氮碱基，存在于 DNA 和 RNA 中，是遗传信息的“字母”之一。

腺嘌呤 = DNA / RNA 中的重要遗传碱基

2) 腺嘌呤出现在哪里

• DNA：与 胸腺嘧啶（T）配对
• RNA：与 尿嘧啶（U）配对
• ATP：能量分子的重要组成部分

3) 腺嘌呤的配对规则（必考）

DNA 中：

• A ↔ T（2 条氢键）

RNA 中：

• A ↔ U

这些规则保证了遗传信息的准确复制和表达。

4) 腺嘌呤的类别

腺嘌呤属于 嘌呤（purine）：

• 结构为双环
• 体积较大

嘌呤：A、G 嘧啶：C、T、U

5) 腺嘌呤在 DNA 中的作用

• 与脱氧核糖结合
• 构成核苷酸
• 其排列顺序决定遗传信息

碱基变化可能导致突变。

6) 腺嘌呤与能量（ATP）

腺嘌呤是 ATP（三磷酸腺苷）的一部分：

• 为细胞活动提供能量

一句话考试版总结

腺嘌呤是 DNA 中与 T 配对、RNA 中与 U 配对的嘌呤碱基。

如果你需要，我可以把 Adenine / Thymine / Cytosine / Guanine 做成 Science 10 中英对照碱基配对表或互动闪卡，方便系统复习。

English — nitrogenous base (thorough explanation)

1) What a nitrogenous base is (core idea)

A nitrogenous base is a nitrogen-containing molecule that is part of a nucleotide, the building block of DNA and RNA.

Nitrogenous base = the “letter” of the genetic code

Each nucleotide has:

1. A phosphate group
2. A sugar
3. A nitrogenous base

The sequence of bases stores genetic information.

2) The five nitrogenous bases (must know)

In DNA:

• Adenine (A)
• Thymine (T)
• Cytosine (C)
• Guanine (G)

In RNA:

• Adenine (A)
• Uracil (U) (replaces thymine)
• Cytosine (C)
• Guanine (G)

📌 Only the bases change; the sugar–phosphate backbone stays the same.

3) Two base groups: purines vs pyrimidines

Purines (two rings):

• Adenine (A)
• Guanine (G)

Pyrimidines (one ring):

• Cytosine (C)
• Thymine (T)
• Uracil (U)

This size difference explains base pairing rules.

4) Base pairing rules (DNA vs RNA)

DNA base pairing:

• A pairs with T (2 hydrogen bonds)
• C pairs with G (3 hydrogen bonds)

RNA base pairing:

• A pairs with U
• C pairs with G

Hydrogen bonds hold paired bases together, forming the double helix in DNA.

5) Why nitrogenous bases matter

Nitrogenous bases:

• Store genetic information
• Determine proteins made by a cell
• Allow DNA to replicate accurately
• Enable RNA to carry instructions for protein synthesis

Changing a base (a mutation) can change traits.

6) Base vs nucleotide (common confusion)

• Nitrogenous base → one component (A, T/U, C, G)
• Nucleotide → base + sugar + phosphate

Bases encode information; nucleotides build the molecule.

One-sentence exam summary

Nitrogenous bases are nitrogen-containing molecules in DNA and RNA whose sequence stores genetic information.

中文 — nitrogenous base（含氮碱基） 详细解释

1) 什么是含氮碱基（核心概念）

含氮碱基是含有氮原子的分子，是 DNA 和 RNA 的核苷酸组成部分之一。

含氮碱基 = 遗传信息的“字母”

每个核苷酸由：

1. 磷酸
2. 糖
3. 含氮碱基 组成。

2) 五种含氮碱基（必背）

DNA 中：

• 腺嘌呤（A）
• 胸腺嘧啶（T）
• 胞嘧啶（C）
• 鸟嘌呤（G）

RNA 中：

• 腺嘌呤（A）
• 尿嘧啶（U）
• 胞嘧啶（C）
• 鸟嘌呤（G）

3) 含氮碱基的两大类

嘌呤（双环）：

• A、G

嘧啶（单环）：

• C、T、U

4) 碱基配对规则（考试重点）

DNA：

• A ↔ T
• C ↔ G

RNA：

• A ↔ U
• C ↔ G

这些配对通过氢键连接，使 DNA 形成双螺旋结构。

5) 含氮碱基的重要性

• 决定遗传信息
• 指导蛋白质合成
• 保证 DNA 复制准确
• 碱基改变会导致突变

一句话考试版总结

含氮碱基是 DNA 和 RNA 中储存遗传信息的关键成分。

如果你需要，我可以把 nitrogenous base → nucleotide → DNA → gene 做成 Science 10 中英对照速记卡或互动图解，非常适合系统复习。

English — Sugar in DNA (thorough explanation)

1) What the sugar in DNA is

The sugar found in DNA is called deoxyribose. It is a five-carbon sugar (a pentose) and is one of the three essential parts of a DNA nucleotide.

DNA sugar = deoxyribose

Each DNA nucleotide contains:

1. A phosphate group
2. Deoxyribose sugar
3. A nitrogenous base (A, T, C, or G)

2) Why it’s called deoxyribose

• “Deoxy-” means missing an oxygen
• Deoxyribose has one less oxygen atom than ribose (the sugar in RNA)

📌 This small difference makes DNA:

• More stable
• Better for long-term information storage

3) What the sugar does in DNA (key functions)

A) Forms the backbone

• Deoxyribose links to phosphate groups
• Together they form the sugar–phosphate backbone
• This backbone gives DNA its shape and strength

B) Connects to bases

• Each sugar attaches to one nitrogenous base
• The sequence of bases carries genetic information
• The sugar itself does not code information, but holds it in place

4) How sugars link DNA together

• The sugar of one nucleotide bonds to the phosphate of the next
• This creates a long chain called a polynucleotide
• The bonds are called phosphodiester bonds

Two sugar–phosphate backbones twist together to form the double helix.

5) DNA sugar vs RNA sugar (common exam comparison)

| Feature | DNA | RNA | | ------------------- | ------------------ | ------------------ | | Sugar | Deoxyribose | Ribose | | Oxygen at 2′ carbon | ❌ Missing | ✅ Present | | Stability | More stable | Less stable | | Function | Store genetic info | Help make proteins |

6) Why sugar matters (big picture)

Without the sugar:

• DNA nucleotides could not link
• DNA would fall apart
• Genetic information could not be stored or copied

Sugar = the structural “frame” that holds DNA together

One-sentence exam summary

The sugar in DNA is deoxyribose, which forms the sugar–phosphate backbone and supports the structure of the DNA molecule.

中文 — DNA 中的糖（详细解释）

1) DNA 中的糖是什么

DNA 中的糖叫 脱氧核糖（deoxyribose），是一种五碳糖。

DNA 的糖 = 脱氧核糖

每个 DNA 核苷酸由三部分组成：

1. 磷酸基团
2. 脱氧核糖
3. 含氮碱基（A、T、C、G）

2) 为什么叫“脱氧”核糖

• “脱氧”表示 少一个氧原子
• 脱氧核糖比 RNA 中的核糖 少一个氧

📌 这使 DNA：

• 更稳定
• 适合长期储存遗传信息

3) 糖在 DNA 中的作用（重点）

① 构成骨架

• 脱氧核糖与磷酸交替连接
• 形成 糖—磷酸骨架
• 为 DNA 提供支撑和形状

② 连接碱基

• 每个糖连接一个碱基
• 碱基顺序决定遗传信息
• 糖本身不存信息，但固定信息

4) DNA 是如何连成链的

• 一个核苷酸的糖
• 与下一个核苷酸的磷酸相连
• 形成 磷酸二酯键

两条这样的链相互缠绕，形成 DNA 双螺旋结构。

5) DNA 糖 vs RNA 糖（常考对比）

| 项目 | DNA | RNA | | --- | ------ | ----- | | 糖 | 脱氧核糖 | 核糖 | | 氧原子 | 少一个 | 多一个 | | 稳定性 | 高 | 低 | | 功能 | 储存遗传信息 | 蛋白质合成 |

一句话考试版总结

DNA 中的糖是脱氧核糖，它与磷酸一起形成 DNA 的骨架结构。

如果你需要，我可以把 nucleotide → sugar → phosphate → DNA backbone 做成 中英对照闪卡或可交互 HTML 图解，直接用于 Science 10 复习或教学。

English — phosphate group (thorough explanation)

1) What a phosphate group is (core idea)

A phosphate group is a chemical group made of one phosphorus atom bonded to four oxygen atoms (PO₄³⁻).

In biology, phosphate groups are extremely important because they:

• Form part of DNA and RNA
• Store and transfer energy
• Help link molecules together

Phosphate group = a key chemical unit for structure and energy

2) Phosphate group in nucleotides (Science 10 focus)

In DNA and RNA, every nucleotide contains:

1. A phosphate group
2. A sugar
3. A nitrogenous base

The phosphate group:

• Connects to the sugar of one nucleotide
• Links to the sugar of the next nucleotide

This creates the sugar–phosphate backbone of DNA and RNA.

📌 Without phosphate groups, nucleotides could not form long chains.

3) Phosphodiester bonds (important term)

Phosphate groups form phosphodiester bonds, which:

• Join one sugar to the next sugar
• Hold DNA and RNA strands together
• Are very strong and stable

This is why DNA can safely store genetic information.

4) Phosphate groups and energy (ATP connection)

Phosphate groups are also central to energy transfer.

In ATP (adenosine triphosphate):

• Energy is stored in the bonds between phosphate groups
• When a phosphate group is removed, energy is released

📌 This energy powers cell activities like:

• Movement
• Active transport
• Protein synthesis

5) Other roles of phosphate groups

Phosphate groups also:

• Help regulate enzymes (phosphorylation)
• Are part of cell membranes (phospholipids)
• Carry negative charge, helping DNA dissolve in water

One-sentence exam summary

A phosphate group links nucleotides together to form the sugar–phosphate backbone of DNA and stores energy in molecules like ATP.

中文 — phosphate group（磷酸基团） 详细解释

1) 什么是磷酸基团（核心概念）

磷酸基团是一种由 1 个磷原子和 4 个氧原子组成的化学基团（PO₄³⁻）。

在生物体内，磷酸基团非常重要，因为它：

• 构成 DNA 和 RNA
• 参与 能量储存和释放
• 帮助分子彼此连接

磷酸基团 = 结构与能量的关键单位

2) 磷酸基团在核苷酸中的作用（必考）

DNA 和 RNA 中的每个核苷酸都包含：

1. 磷酸基团
2. 糖
3. 含氮碱基

磷酸基团的作用：

• 把一个核苷酸的糖
• 与下一个核苷酸的糖连接起来

从而形成 糖—磷酸骨架。

3) 磷酸二酯键（重要名词）

磷酸基团形成的磷酸二酯键：

• 把相邻核苷酸连接起来
• 使 DNA / RNA 链稳定
• 是遗传信息的“支架”

4) 磷酸基团与能量（ATP）

在 ATP（三磷酸腺苷）中：

• 能量储存在磷酸基团之间的键中
• 当磷酸基团被移除时，释放能量

这些能量用于：

• 肌肉收缩
• 主动运输
• 生物合成

5) 磷酸基团的其他作用

• 调控蛋白质活性（磷酸化）
• 构成细胞膜（磷脂）
• 使 DNA 带负电、易溶于水

一句话考试版总结

磷酸基团把核苷酸连接成 DNA 的骨架，并在 ATP 中储存和释放能量。

如果你愿意，我可以把 phosphate group → nucleotide → DNA backbone → ATP 做成 Science 10 中英对照概念图或互动闪卡，非常适合你现在的生物复习进度。

English — algal blooms (thorough explanation)

1) What algal blooms are (core idea)

Algal blooms occur when algae grow very quickly and in large numbers in a body of water, often turning the water green, blue-green, or brown.

Algal bloom = rapid overgrowth of algae in water

Blooms commonly happen in ponds, lakes, rivers, and coastal waters.

2) Why algal blooms happen

Algal blooms are caused by a combination of favorable conditions:

• Excess nutrients (especially nitrogen and phosphorus)

• From fertilizers, sewage, farm runoff

• Warm temperatures
• Strong sunlight
• Still or slow-moving water

This nutrient enrichment is called eutrophication.

3) Types of algal blooms

A) Non-toxic blooms

• Algae grow rapidly
• Water looks green or cloudy
• Still harmful if oxygen drops

B) Harmful algal blooms (HABs)

• Often caused by cyanobacteria (blue-green algae)
• Can release toxins
• Dangerous to fish, pets, wildlife, and humans

4) Why algal blooms are harmful (Science 10 focus)

Even though algae are producers, blooms can damage ecosystems:

• Block sunlight → underwater plants die
• Reduce oxygen when algae die and decompose
• Cause fish kills
• Disrupt food webs
• Some toxins cause illness if water is swallowed or touched

📌 This oxygen loss is called hypoxia.

5) Effects on humans

Algal blooms can:

• Contaminate drinking water
• Close beaches and lakes
• Kill fish and livestock
• Cause skin irritation, stomach illness, or neurological symptoms

6) Algal blooms in ponds (exam-friendly example)

In a pond:

1. Fertilizer runoff enters the water
2. Algae multiply rapidly
3. Oxygen levels drop
4. Fish and insects may die
5. Pond biodiversity decreases

7) How algal blooms can be reduced

• Reduce fertilizer use
• Improve wastewater treatment
• Protect shoreline vegetation
• Control nutrient runoff

One-sentence exam summary

Algal blooms are rapid increases in algae caused by excess nutrients, often leading to low oxygen and ecosystem damage.

中文 — algal blooms（藻华 / 藻类暴发） 详细解释

1) 什么是藻华（核心概念）

藻华（algal blooms）是指藻类在水体中迅速、大量繁殖的现象，常使水体呈现绿色、蓝绿色或褐色。

藻华 = 藻类数量突然暴增

2) 藻华产生的原因

藻华通常由以下因素共同引起：

• 养分过多（氮、磷）
• 水温升高
• 阳光充足
• 水流缓慢或静止

这种水体富营养化过程叫 水体富营养化。

3) 藻华的类型

① 无毒藻华

• 藻类大量繁殖
• 会导致水体缺氧

② 有害藻华

• 常由蓝藻（蓝绿藻）引起
• 释放毒素
• 对鱼类、人类和动物有危险

4) 藻华为什么有害（考试重点）

• 遮挡阳光，水草死亡
• 藻类分解消耗氧气
• 造成鱼类死亡
• 破坏生态系统平衡

5) 对人类的影响

• 饮用水污染
• 湖泊和海滩关闭
• 人和动物中毒

6) 池塘中的藻华示例（常考）

1. 肥料进入池塘
2. 藻类迅速繁殖
3. 水中氧气下降
4. 鱼类死亡
5. 生物多样性下降

一句话考试版总结

藻华是由养分过多引起的藻类快速繁殖，会导致水体缺氧和生态破坏。

如果你需要，我可以把 algae / algal / algal bloom / eutrophication 做成 Science 10 中英对照概念图或互动闪卡，直接用于考试复习。

English — algal (thorough explanation)

1) What algal means (core idea)

Algal is an adjective that means related to or caused by algae.

Algal = having to do with algae

It is used to describe things like algal cells, algal growth, or algal blooms.

2) What algae are (quick reminder)

Algae are mostly aquatic, photosynthetic organisms. They can be:

• Microscopic (single-celled)
• Macroscopic (large seaweeds)

Algae are not true plants, but many behave like plants because they:

• Contain chlorophyll
• Perform photosynthesis

3) Common uses of “algal” in science (Science 10 focus)

Algal growth

• Increase in algae due to sunlight and nutrients

Algal bloom

• A rapid increase in algae population
• Often turns water green
• Can reduce oxygen in water and harm animals

Algal cells

• Individual algae cells seen under a microscope

Algal mats

• Thick layers of algae covering water surfaces or rocks

4) Algal blooms — important ecological example

Algal blooms often occur when:

• Nutrients (nitrogen, phosphorus) are high
• Water is warm
• Sunlight is abundant

Effects:

• Block sunlight for other plants
• Reduce dissolved oxygen
• May produce toxins (in some species)

📌 This process is linked to eutrophication.

5) Why algal organisms are important

Algal organisms:

• Are primary producers
• Form the base of many aquatic food chains
• Produce a large amount of Earth’s oxygen
• Support ecosystems like ponds, lakes, and oceans

6) Grammar note

• Algae → noun (plural)
• Alga → noun (singular)
• Algal → adjective

📌 Example:

Algal growth increases in warm, nutrient-rich water.

中文 — algal（藻类的 / 与藻类有关的） 详细解释

1) “algal”的基本含义

Algal 是一个形容词，意思是 “与藻类有关的”。

Algal = 藻类的

2) 藻类是什么（简单回顾）

藻类是大多生活在水中的能进行光合作用的生物，可以是：

• 单细胞（显微藻类）
• 多细胞（大型海藻）

3) “algal”的常见科学用法（考试常见）

• 藻类生长（algal growth）
• 藻华 / 藻类暴发（algal bloom）
• 藻类细胞（algal cells）
• 藻毯（algal mats）

4) 藻华（重点）

藻华通常发生在：

• 养分多
• 温度高
• 光照强

影响：

• 水体缺氧
• 鱼类死亡
• 水质恶化

5) 藻类的重要性

• 是水生生态系统的生产者
• 是食物链的基础
• 产生大量氧气

6) 词性总结（考试加分点）

• alga：单数，藻
• algae：复数，藻类
• algal：形容词，藻类的

一句话考试版总结

Algal means related to algae, especially in aquatic ecosystems. Algal 指与藻类有关的事物。

如果你需要，我可以把 alga / algae / algal 做成 Science 10 中英对照速记卡或易错点练习题，非常适合考试复习。

English — amoebas (thorough explanation)

1) What amoebas are (core idea)

Amoebas are microscopic, single-celled protists that usually live in water or moist environments. They are famous for their constantly changing shape.

Amoeba = one cell that changes shape to move and eat

2) Where amoebas live

Amoebas are commonly found in:

• Ponds and lakes
• Wet soil
• Slow-moving freshwater
• Inside other organisms (some species)

Most amoebas are free-living and harmless, but a few can cause disease.

3) How amoebas move — pseudopodia

Amoebas move using pseudopodia (“false feet”).

• The cell membrane pushes outward
• Cytoplasm flows into the extension
• The cell slowly pulls itself forward

This movement is called amoeboid movement.

4) How amoebas eat (ingestion by phagocytosis)

Amoebas are heterotrophic (they must eat food).

Steps:

1. Amoeba surrounds food with pseudopodia
2. Food is engulfed
3. A food vacuole forms
4. Enzymes digest the food
5. Nutrients enter the cytoplasm
6. Waste is released

This feeding method is called phagocytosis.

5) Important cell structures (Science 10 focus)

| Structure | Function | | ------------------- | -------------------------- | | Pseudopodia | Movement and feeding | | Cell membrane | Controls entry and exit | | Cytoplasm | Site of chemical reactions | | Nucleus | Controls cell activities | | Food vacuole | Digestion | | Contractile vacuole | Pumps out excess water |

6) Water balance (very important)

Because amoebas live in freshwater:

• Water constantly enters the cell by osmosis
• The contractile vacuole removes extra water
• This prevents the cell from bursting

7) How amoebas reproduce

• Reproduce by binary fission
• One cell divides into two identical cells
• This is asexual reproduction

8) Why amoebas are important

• Feed on bacteria → help control populations
• Part of aquatic food webs
• Used in biology to study cell movement and feeding
• Show how one cell can perform all life functions

One-sentence exam summary

Amoebas are single-celled protists that move and eat using pseudopodia.

中文 — amoebas（变形虫） 详细解释

1) 变形虫是什么（核心概念）

变形虫（amoebas）是生活在水或潮湿环境中的单细胞原生生物。 它们最显著的特点是形状不断变化。

变形虫 = 靠改变形状来运动和进食的单细胞生物

2) 变形虫的生活环境

• 池塘
• 湖泊
• 潮湿土壤
• 其他生物体内

大多数变形虫对人类无害。

3) 变形虫如何运动 —— 伪足

变形虫通过伪足运动：

• 细胞向前伸出伪足
• 细胞质流入
• 整个细胞向前移动

这种方式叫 变形运动。

4) 变形虫如何进食（吞噬作用）

变形虫是异养生物，进食过程如下：

1. 伪足包围食物
2. 食物被吞入
3. 形成食物泡
4. 消化酶分解食物
5. 营养进入细胞质
6. 废物排出

这种方式称为 吞噬作用（phagocytosis）。

5) 重要结构（考试重点）

| 结构 | 功能 | | --- | ------- | | 伪足 | 运动、捕食 | | 细胞膜 | 控制物质进出 | | 细胞质 | 生命活动场所 | | 细胞核 | 控制细胞 | | 食物泡 | 消化 | | 伸缩泡 | 排水、防止胀破 |

6) 一句话考试版总结

变形虫是通过伪足运动和进食的单细胞原生生物。

如果你需要，我可以把 Amoeba / Paramecium / Euglena 做成 Science 10 中英对照比较表或互动闪卡，非常适合系统复习与课堂讲解。

English — Euglena (thorough explanation)

1) What Euglena is (core idea)

Euglena is a microscopic, single-celled protist that lives mainly in freshwater. It is special because it can act like both a plant and an animal.

Euglena = a mix of plant-like and animal-like traits

2) Why Euglena is unique (exam favorite)

Euglena is often used to show that living things do not always fit neatly into one group.

• Plant-like:

• Has chloroplasts

• Can do photosynthesis

• Animal-like:

• Can move

• Can feed on organic matter when light is unavailable

This flexible nutrition is called mixotrophic.

3) How Euglena moves

Euglena moves using a flagellum (a long, whip-like structure).

• The flagellum spins or whips
• Pulls the cell through water
• Allows Euglena to move toward light

4) How Euglena gets energy (two ways)

A) Photosynthesis (like plants)

• Uses chloroplasts
• Needs light, carbon dioxide, and water
• Produces glucose and oxygen

B) Heterotrophic feeding (like animals)

• When light is limited
• Absorbs nutrients from the environment

5) Important cell structures (Science 10 focus)

| Structure | Function | | ------------------- | -------------------------------------- | | Flagellum | Movement | | Eyespot (stigma) | Detects light | | Chloroplasts | Photosynthesis | | Nucleus | Controls cell activities | | Pellicle | Flexible outer layer (not a cell wall) | | Contractile vacuole | Removes excess water |

6) Eyespot and light detection (very important)

Euglena has a red eyespot that:

• Detects the direction of light
• Helps Euglena swim toward light
• Increases photosynthesis efficiency

This behavior is called phototaxis.

7) Where Euglena lives

• Ponds
• Lakes
• Slow-moving freshwater
• Nutrient-rich water

Euglena often thrives in water with plenty of light.

8) How Euglena reproduces

• Reproduces by binary fission
• One cell divides into two identical cells

One-sentence exam summary

Euglena is a single-celled protist that can photosynthesize like a plant and move like an animal using a flagellum.

中文 — Euglena（眼虫） 详细解释

1) 眼虫是什么（核心概念）

眼虫（Euglena）是一种生活在淡水中的单细胞原生生物。 它的最大特点是：既像植物，又像动物。

眼虫 = 兼具植物和动物特征的原生生物

2) 眼虫为什么特殊（考试重点）

• 像植物：

• 有叶绿体

• 能进行光合作用

• 像动物：

• 能主动运动

• 缺光时可吸收有机物获取能量

这种双重营养方式称为 混合营养（mixotrophic）。

3) 眼虫如何运动

• 通过一根鞭毛运动
• 鞭毛摆动，推动细胞前进

4) 眼虫如何获取能量

① 光合作用（有光时）

• 利用叶绿体
• 制造葡萄糖

② 异养方式（无光时）

• 从环境中吸收营养

5) 重要结构（必考）

| 结构 | 功能 | | --- | ------- | | 鞭毛 | 运动 | | 眼点 | 感光 | | 叶绿体 | 光合作用 | | 细胞核 | 控制生命活动 | | 表膜 | 保护并保持形状 | | 伸缩泡 | 排出多余水分 |

6) 眼点的作用（高频考点）

• 感知光线方向
• 帮助眼虫向光移动
• 提高光合作用效率

这种向光移动的行为叫 趋光性。

一句话考试版总结

眼虫是一种能进行光合作用、又能主动运动的单细胞原生生物。

如果你愿意，我可以把 Euglena / Paramecium / Amoeba 做成 Science 10 中英对照对比表或互动闪卡，非常适合系统复习。

English — Paramecium (thorough explanation)

1) What Paramecium is (core idea)

Paramecium is a microscopic, single-celled protist that lives mainly in freshwater, such as ponds.

Even though it is only one cell, it can:

• Move
• Eat
• Digest food
• Remove waste
• Respond to its environment

Paramecium = a single cell that does everything a living organism needs to do

2) Where Paramecium lives

Paramecium is commonly found in:

• Ponds
• Lakes
• Slow-moving freshwater
• Water with decaying organic matter

These environments contain many bacteria, which Paramecium feeds on.

3) How Paramecium moves — cilia

Paramecium is covered with tiny hair-like structures called cilia.

Cilia:

• Beat in coordinated waves
• Pull Paramecium through water
• Help sweep food into the cell mouth

📌 This makes Paramecium very active compared to many other protists.

4) How Paramecium eats (ingestion & digestion)

Paramecium is heterotrophic (cannot make its own food).

Steps:

1. Cilia sweep food (bacteria, algae) into the oral groove
2. Food enters the cell mouth
3. A food vacuole forms
4. Enzymes digest the food
5. Nutrients move into the cytoplasm
6. Waste exits the cell

5) Important cell structures (exam focus)

| Structure | Function | | ----------------------- | -------------------------------------- | | Cilia | Movement and feeding | | Oral groove | Directs food inward | | Food vacuole | Digests food | | Contractile vacuole | Pumps out excess water | | Nucleus (macro & micro) | Controls cell functions & reproduction | | Cell membrane | Protects cell and controls entry/exit |

6) How Paramecium controls water (very important)

Because it lives in freshwater:

• Water constantly enters the cell by osmosis
• The contractile vacuole collects excess water
• It periodically squeezes the water out