📚 Year 7 CCEA Biology: Formula & Theorem Quick Reference Handbook | Year 7 CCEA 生物：公式定理速查手册
This handbook brings together the key formulas, word equations and important relationships you will meet in Year 7 CCEA Biology. Use it as a quick‑reference guide when you are revising or completing homework. Every 'formula' is explained in plain English, followed by its Chinese equivalent so that you can master the material in both languages.
本手册汇集了你在 Year 7 CCEA 生物课程中会遇到的各类关键公式、文字方程式和重要关系。复习或做作业时可将它作为速查工具。每个‘公式’都先用简易英文解释，再附上对应的中文，帮助你在双语环境下牢固掌握知识。
1. The Magnification Formula | 放大倍数公式
agnification = Size of image ÷ Actual size of object. Always make sure both sizes are in the same unit before you divide.
当你通过显微镜观察时，物体会被放大许多倍。放大倍数可以用一个简单公式计算：放大倍数 = 图像大小 ÷ 实际物体大小。计算前务必确保两个大小的单位一致。
M = I ÷ A
res 3 mm and its real length is 0.01 mm, the magnification is 3 ÷ 0.01 = 300 ×. The symbol '×' means 'times'.
如果某细胞图像长 3 mm，而实际长度为 0.01 mm，那么放大倍数就是 3 ÷ 0.01 = 300 ×。符号‘×’表示‘倍’。
| Symbol | Meaning | 含义 |
| M | Magnification | 放大倍数 |
| I | Size of image | 图像大小 |
| A | Actual size | 实际大小 |
2. Photosynthesis Word Equation | 光合作用文字方程式
Photosynthesis is the process by which green plants make their own food. The overall reaction can be written as a word equation. Light energy is captured by chlorophyll, found in chloroplasts, and is essential for the reaction to take place.
光合作用是绿色植物制造自身养料的过程。其总反应可用一个文字方程式来表示。叶绿体中的叶绿素捕获光能，这是反应发生的必要条件。
Carbon dioxide + Water → Glucose + Oxygen
二氧化碳 + 水 → 葡萄糖 + 氧气
Notice that the arrow shows the direction of the reaction, and we write 'light energy' and 'chlorophyll' above or below the arrow. Glucose is the sugar made and oxygen is released as a by‑product.
注意箭头表示反应方向，通常我们会在箭头上方或下方写上‘光能’和‘叶绿素’。葡萄糖是生成的糖类，氧气则作为副产品释放出来。
- Reactants: carbon dioxide (CO₂) and water (H₂O) | 反应物：二氧化碳和水
- Products: glucose (C₆H₁₂O₆) and oxygen (O₂) | 生成物：葡萄糖和氧气
- Condition: light energy and chlorophyll | 条件：光能和叶绿素
3. Aerobic Respiration Word Equation | 有氧呼吸文字方程式
Aerobic respiration is the process that releases energy from glucose using oxygen. It takes place in the mitochondria of plant and animal cells and produces carbon dioxide and water as waste.
有氧呼吸是利用氧气从葡萄糖中释放能量的过程。它发生在植物和动物细胞的线粒体中，产生二氧化碳和水作为废物。
Glucose + Oxygen → Carbon dioxide + Water (+ energy)
葡萄糖 + 氧气 → 二氧化碳 + 水（+ 能量）
Energy is not a chemical substance but is released as ATP. The word equation helps you remember what goes in and what comes out.
能量不是化学物质，而是以 ATP 的形式释放。这个文字方程式帮助你记住反应物和生成物。
- This is the opposite of photosynthesis in terms of chemicals. | 从化学物质来看，这正好与光合作用相反。
- Energy is used for movement, growth and keeping warm. | 能量用于运动、生长和保持体温。
4. Food Tests — Key Reactions | 食物测试——关键反应
ou can test for different nutrients using simple reagents. Each test follows a predictable 'formula'‑like pattern: specific reagent + specific nutrient → colour change.
在实验室里，你可以用简单试剂来检测不同的营养素。每个测试都遵循一个类似‘公式’的规律：特定试剂 + 特定营养素 → 颜色变化。
| Nutrient | 营养素 | Reagent | 试剂 | Positive result | 阳性结果 |
| Starch | 淀粉 | Iodine solution | 碘液 | Blue‑black | 蓝黑色 |
| Glucose (reducing sugar) | 葡萄糖 | Benedict's solution + heat | 本尼迪克特溶液 + 加热 | Brick‑red | 砖红色 |
| Protein | 蛋白质 | Biuret solution | 双缩脲试剂 | Purple/violet | 紫色 |
| Lipid (fat) | 脂质 | Ethanol + water (shake) | 乙醇 + 水（摇匀） | Cloudy white emulsion | 白色乳浊液 |
Remember, a blue‑black colour with iodine confirms starch, and a brick‑red precipitate with hot Benedict's confirms glucose. These tests are fundamental in Year 7.
记住，碘液变为蓝黑色确证淀粉存在，本尼迪克特加热后出现砖红色沉淀确证葡萄糖。这些测试是 Year 7 的基础内容。
5. Digestive Enzymes — Lock and Key Model | 消化酶——锁钥模型
Enzymes are biological catalysts that speed up digestion. The lock‑and‑key model explains that each enzyme's active site fits a specific substrate, like a key fits a lock. You can think of this as a 'matching formula'.
酶是加速消化的生物催化剂。锁钥模型解释了每种酶的活性部位只与特定底物匹配，就像钥匙配锁。你可以把这看作一种‘配对公式’。
Amylase + Starch → Maltose (sugar)
淀粉酶 + 淀粉 → 麦芽糖
Protease + Protein → Amino acids
蛋白酶 + 蛋白质 → 氨基酸
Lipase + Lipid → Fatty acids + Glycerol
脂肪酶 + 脂质 → 脂肪酸 + 甘油
The enzyme is not used up in the reaction, so it can work again and again. Temperature and pH affect how well the lock‑and‑key shape fits.
酶在反应中不被消耗，因此可以反复使用。温度和 pH 值会影响锁钥形状的匹配程度。
6. Cell Structures — Key Organelles | 细胞结构——关键细胞器
Every living cell contains tiny structures called organelles. Learning their names and jobs is like memorising a set of rules. A typical plant cell and animal cell share some organelles, while others are unique.
每个活细胞都含有微小的结构，称为细胞器。记住它们的名称和功能就像记住一组规则。典型的植物细胞和动物细胞有一些共同的细胞器，也有一些各自特有的。
| Organelle | 细胞器 | Function ('job') | 功能 | Present in | 存在于 |
| Nucleus | 细胞核 | Controls cell activities, contains DNA | 控制细胞活动，含 DNA | Both | 两者都有 |
| Cytoplasm | 细胞质 | Where chemical reactions occur | 化学反应发生的地方 | Both | 两者都有 |
| Cell membrane | 细胞膜 | Controls what enters and leaves the cell | 控制物质进出 | Both | 两者都有 |
| Mitochondria | 线粒体 | Site of aerobic respiration | 有氧呼吸场所 | Both | 两者都有 |
| Cell wall | 细胞壁 | Provides support and shape | 提供支撑和形状 | Plant only | 仅植物 |
| Chloroplast | 叶绿体 | Contains chlorophyll for photosynthesis | 含叶绿素，进行光合作用 | Plant only | 仅植物 |
| Permanent vacuole | 中央大液泡 | Stores cell sap, helps keep cell turgid | 储存细胞液，维持细胞紧张 | Plant only | 仅植物 |
Remember: animal cells do NOT have a cell wall, chloroplasts or a large permanent vacuole. This is a key difference.
记住：动物细胞没有细胞壁、叶绿体和中央大液泡。这是一个关键区别。
7. Levels of Organisation | 组织层级
things are organised from the smallest unit to the whole organism. You can write this as a 'building‑up' formula: Cells → Tissues → Organs → Organ systems → Organism.
在生物学中，生命体从最小单位到整个有机体层层组织。你可以把这写成一条‘构建公式’：细胞 → 组织 → 器官 → 器官系统 → 生物体。
Cell → Tissue → Organ → Organ System → Organism
(organ system) → human (organism). Each level works together to carry out life processes.
例如：肌细胞 → 肌肉组织 → 胃（器官） → 消化系统（器官系统） → 人（生物体）。每个层级协同工作，完成生命活动。
8. Genes and Alleles — Punnett Square | 基因和等位基因——旁氏方格
Inheritance follows mathematical patterns. A Punnett square is a tool that predicts the possible genetic outcomes of a cross. You can think of it as a probability 'formula'.
遗传遵循数学模式。旁氏方格是一种预测杂交可能遗传结果的工具，你可以把它看成一个概率‘公式’。
For a simple example: a pure breeding tall plant (TT) crossed with a short plant (tt). Each parent gives one allele.
举一个简单例子：纯种高茎植物（TT）与矮茎植物（tt）杂交。每个亲本提供一个等位基因。
| T | T | |
| t | Tt | Tt |
| t | Tt | Tt |
All offspring are Tt — tall because T (tall) is dominant. The ratio is 100% tall in the first generation. If you cross two Tt plants, the ratio becomes 3:1 (tall : short).
所有后代基因型都是 Tt —— 因为 T（高）是显性，所以全部表现为高茎，第一代表型比为 100% 高茎。如果让两个 Tt 个体杂交，表型比将变为 3:1（高：矮）。
- Dominant allele: capital letter (e.g. T) | 显性等位基因：大写字母（如 T）
- Recessive allele: lower case (e.g. t) | 隐性等位基因：小写字母（如 t）
- Genotype: genetic makeup (TT, Tt, tt) | 基因型：遗传组成
- Phenotype: physical appearance (tall or short) | 表现型：外在特征
9. Characteristics of Living Things — MRS GREN | 生物体的特征——MRS GREN
All living organisms share certain life processes. The acronym MRS GREN helps you remember seven characteristics. It acts as a checklist 'formula' to decide whether something is alive.
所有生物体都有某些共同的生命活动。首字母缩写 MRS GREN 帮助你记住七个特征。它就像一个核查‘公式’，用来判断某物是否为生物。
| Letter | 字母 | Stands for | 代表 | Meaning | 含义 |
| M | Movement | 运动 | Change position or place | 改变位置或地点 |
| R | Respiration | 呼吸 | Release energy from food | 从食物中释放能量 |
| S | Sensitivity | 感应 | Detect and respond to stimuli | 探测并响应刺激 |
| G | Growth | 生长 | Increase in size and complexity | 体积和复杂度增加 |
| R | Reproduction | 繁殖 | Produce offspring | 产生后代 |
| E | Excretion | 排泄 | Remove waste products | 排出废物 |
| N | Nutrition | 营养 | Take in and use food materials | 摄取和利用养料 |
If an object shows all seven processes, it is considered a living organism. A car may move but it does not grow or reproduce, so it is non‑living.
如果一个物体表现出全部七个生命过程，它就被视为生物体。汽车能运动，但不会生长或繁殖，因此它不是生物。
10. Balanced Diet Components — Nutrient 'Pie' | 均衡饮食的组成——营养素‘分配图’
A balanced diet contains the correct proportions of different food groups. The 'formula' for health can be expressed as a list of essential nutrients and their main functions.
均衡饮食包含比例合适的各类食物。健康的‘公式’可以用必需营养素的清单及其主要功能来表达。
| Nutrient | 营养素 | Main function | 主要功能 | Good sources | 良好来源 |
| Carbohydrates | 碳水化合物 | Provide energy | 提供能量 | Bread, rice, potatoes | 面包、米饭、土豆 |
| Proteins | 蛋白质 | Growth and repair | 生长与修复 | Meat, beans, eggs | 肉类、豆类、蛋 |
| Lipids (fats) | 脂质 | Energy store, insulation | 储存能量，隔热 | Butter, oils, nuts | 黄油、油、坚果 |
| Vitamins e.g. C, D | 维生素 | Prevent deficiency diseases | 预防缺乏病 | Fruits, vegetables, sunlight | 水果、蔬菜、阳光 |
| Minerals e.g. calcium, iron | 矿物质 | Strong bones, healthy blood | 强壮骨骼、健康血液 | Milk, green vegetables, red meat | 牛奶、绿叶蔬菜、红肉 |
| Fibre (roughage) | 纤维素 | Helps move food through gut | 帮助食物通过肠道 | Wholegrains, fruit skin | 全谷物、果皮 |
| Water | 水 | Solvent, transport, temperature control | 溶剂、运输、调温 | Drinks, many foods | 饮料、多种食物 |
Too much of any one group can lead to health problems. The 'Eatwell Plate' model helps you visualise the ideal proportions.
任何一类过多都会引发健康问题。‘饮食指南餐盘’模型帮助你直观了解理想比例。
11. The Energy Pyramid — Energy Transfer Rule | 能量金字塔——能量传递规则
In a food chain, energy is transferred from one trophic level to the next, but most of the energy is lost as heat and through life processes. The pyramid of energy always has a broad base and narrows at the top.
在食物链中，能量从一个营养级传递到下一个，但大部分能量以热能和生命活动消耗掉了。能量金字塔总是底部宽、顶部尖。
Producers → Primary consumers → Secondary consumers → Tertiary consumers
生产者 → 初级消费者 → 次级消费者 → 三级消费者
Only about 10% of the energy at one level is passed on to the next. This '10% rule' explains why food chains rarely have more than four or five links.
大约只有上一营养级能量的 10% 传递到下一级。这条‘10% 规则’解释了为什么食物链很少超过四到五个环节。
- Producers (plants) capture light energy during photosynthesis. | 生产者（植物）通过光合作用捕获光能。
- Energy is lost as heat, in movement and in undigested waste. | 能量因散热、运动和未消化的废物而流失。
12. Human Reproductive System — Key Terms | 人类生殖系统——关键术语
The human reproductive system can be summarised by a set of 'equations' hat describe fertilisation and development: Sperm + Egg → Zygote → Embryo → Foetus → Baby.
人类生殖系统可以用一组‘方程式’来描述受精和发育过程：精子 + 卵子 → 受精卵 → 胚胎 → 胎儿 → 婴儿。
Sperm (23 chromosomes) + Egg (23 chromosomes) → Zygote (46 chromosomes)
精子（23条染色体） + 卵子（23条染色体） → 受精卵（46条染色体）
This restores the full set of chromosomes. The zygote then divides by mitosis to form an embryo, which implants in the uterus lining and develops over 9 months.
这恢复了完整的染色体数目。受精卵然后通过有丝分裂形成胚胎，着床于子宫内膜，并在 9 个月内发育。
- Male gamete: sperm, produced in testes. | 雄性配子：精子，在睾丸中产生。
- Female gamete: egg (ovum), produced in ovaries. | 雌性配子：卵细胞，在卵巢中产生。
- Fertilisation occurs in the oviduct (fallopian tube). | 受精发生在输卵管。
- The placenta provides oxygen and nutrients to the foetus and removes waste. | 胎盘为胎儿提供氧气和营养，并排除废物。
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