Year 8 WJEC Biology: Core Curriculum Overview | Year 8 WJEC 生物：核心知识点梳理

📚 Year 8 WJEC Biology: Core Curriculum Overview | Year 8 WJEC 生物：核心知识点梳理

Welcome to your comprehensive revision guide for Year 8 WJEC Biology. This article covers the essential topics you need to master, from cells and body systems to genetics and ecosystems. Each section is presented in both English and Chinese to support bilingual learning and exam success.

欢迎阅读 Year 8 WJEC 生物全面复习指南。本文涵盖你需要掌握的核心主题，从细胞和人体系统到遗传与生态系统。每个部分都以英中双语呈现，以支持双语学习和考试成功。

1. Cells and Microscopy | 细胞与显微镜

All living organisms are made of cells. Cells are the basic building blocks of life.

所有生物体都由细胞构成。细胞是生命的基本组成单位。

Animal and plant cells share common structures: a nucleus that controls the cell, cytoplasm where chemical reactions occur, a cell membrane that controls substance movement, and mitochondria where respiration happens. However, plant cells have three extra features – a rigid cell wall made of cellulose, chloroplasts for photosynthesis, and a large permanent vacuole containing cell sap.

动物细胞和植物细胞共有以下结构：控制细胞的细胞核、发生化学反应的细胞质、控制物质进出的细胞膜，以及进行呼吸作用的线粒体。然而，植物细胞还有三个额外的特征——由纤维素组成的坚硬细胞壁、用于光合作用的叶绿体，以及含有细胞液的大中央液泡。

To observe cells, we use a light microscope. The total magnification is calculated by multiplying the eyepiece lens magnification (usually ×10) by the objective lens magnification (e.g. ×4, ×10, ×40). For example, if you use a ×10 eyepiece and a ×40 objective, the total magnification is ×400.

为了观察细胞，我们使用光学显微镜。总放大倍率由目镜放大倍率（通常×10）乘以物镜放大倍率（如×4、×10、×40）计算得出。例如，如果你使用×10目镜和×40物镜，总放大倍率为×400。

The table below compares animal and plant cell structures.

下表比较了动物和植物细胞的结构。

Structure	Animal Cell	Plant Cell
Nucleus	Present	Present
Cytoplasm	Present	Present
Cell membrane	Present	Present
Mitochondria	Present	Present
Cell wall	Absent	Present (cellulose)
Chloroplasts	Absent	Present
Permanent vacuole	Absent	Present (large)

Specialised cells have adaptations that help them carry out specific functions. For example, red blood cells have a biconcave shape and no nucleus to maximise oxygen transport.

特化细胞具有适应特定功能的特征。例如，红细胞呈双凹圆盘状且无细胞核，以最大限度地运输氧气。

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2. Body Systems and Organs | 人体系统与器官

Organs are made of different tissues working together, and organs are organised into organ systems. The main systems studied in Year 8 are the digestive, respiratory, circulatory and skeletal systems.

器官由不同组织协同工作构成，器官又组成器官系统。Year 8 学习的主要系统包括消化系统、呼吸系统、循环系统和骨骼系统。

In the digestive system, food travels through the mouth, oesophagus, stomach, small intestine, large intestine and rectum. Digestion breaks down large insoluble molecules into small soluble ones that can be absorbed into the blood.

在消化系统中，食物经过口腔、食道、胃、小肠、大肠和直肠。消化将大的不溶性分子分解为可溶于水的小分子，以便被血液吸收。

Key digestive processes include mechanical breakdown by teeth, chemical breakdown by enzymes, and absorption of nutrients in the small intestine lined with villi.

关键的消化过程包括牙齿进行的物理分解、酶进行的化学分解，以及在小肠绒毛中进行的营养吸收。

The respiratory system brings oxygen into the body and removes carbon dioxide. Air enters through the trachea, passes into the bronchi, then bronchioles, and finally reaches the alveoli where gas exchange occurs.

呼吸系统将氧气带入体内并排出二氧化碳。空气通过气管进入支气管，再进入细支气管，最后到达发生气体交换的肺泡。

The circulatory system consists of the heart, blood vessels (arteries, veins, capillaries) and blood. It transports oxygen, nutrients, hormones and waste products around the body.

循环系统由心脏、血管（动脉、静脉、毛细血管）和血液组成。它把氧气、营养、激素和废物输送到全身。

• Arteries carry blood away from the heart under high pressure.
• Veins carry blood back to the heart and have valves to prevent backflow.
• Capillaries are tiny vessels where substances are exchanged with cells.

• 动脉在高压下将血液带离心脏。
• 静脉将血液送回心脏，并有瓣膜防止回流。
• 毛细血管是微小的血管，物质在此与细胞进行交换。

The skeletal system provides support, protection and movement. Bones are connected by joints; synovial joints contain lubricating fluid and cartilage to reduce friction.

骨骼系统提供支持、保护和运动功能。骨骼由关节连接；滑膜关节含有润滑液和软骨以减少摩擦。

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3. Reproduction and Puberty | 生殖与青春期

Reproduction is the process by which organisms produce offspring. In humans, sexual reproduction involves the fusion of a male sperm cell and a female egg cell to form a zygote.

生殖是生物产生后代的过程。在人类中，有性生殖涉及男性精细胞与女性卵细胞融合形成受精卵。

The male reproductive system includes the testes (produce sperm), sperm duct, and penis. The female reproductive system includes ovaries (produce eggs), oviducts, uterus and vagina.

男性生殖系统包括睾丸（产生精子）、输精管和阴茎。女性生殖系统包括卵巢（产生卵子）、输卵管、子宫和阴道。

Fertilisation normally takes place in the oviduct. The fertilised egg then implants in the uterus lining, where it develops into an embryo during pregnancy.

受精通常发生在输卵管中。受精卵随后植入子宫内膜，在怀孕期间发育成胚胎。

Puberty is the stage when a child’s body matures into an adult body. Hormones trigger physical changes: in boys, the voice deepens and facial hair grows; in girls, breasts develop and menstruation begins.

青春期是儿童身体发育为成人身体的阶段。激素引发身体变化：男孩声音变低沉、面部毛发长出；女孩乳房发育、月经开始。

Emotional and social changes also occur during adolescence, including mood swings and a desire for independence.

青春期还会发生情绪和社会变化，包括情绪波动和对独立的渴望。

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4. Genetics and Variation | 遗传与变异

Genes are sections of DNA that determine inherited characteristics. They are found on chromosomes inside the nucleus. Humans have 46 chromosomes arranged in 23 pairs.

基因是DNA的片段，它决定遗传特征。它们位于细胞核内的染色体上。人类有46条染色体，排列成23对。

An organism’s genotype is the set of genes it carries; the phenotype is the observable characteristics resulting from the interaction of the genotype with the environment.

生物的基因型是其携带的整套基因；表型是基因型与环境相互作用所表现出的可观察特征。

Some characteristics are determined by a single gene with dominant and recessive alleles. A dominant allele is expressed even if only one copy is present; a recessive allele needs two copies to be expressed.

有些特征由具有显性和隐性等位基因的单个基因决定。显性等位基因即使只有一个拷贝也能表达；隐性等位基因需要两个拷贝才能表达。

Variation within a species can be continuous (e.g. height) or discontinuous (e.g. tongue rolling). It arises from genetic differences, environmental influences, or both.

物种内的变异可以是连续的（如身高）或不连续的（如卷舌能力）。它由遗传差异、环境影响或两者共同引起。

Simple family trees can be used to trace the inheritance of traits. A Punnett square helps predict the probability of offspring inheriting certain alleles.

简单的家系图可用于追踪性状的遗传。庞纳特方格有助于预测后代遗传某些等位基因的概率。

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5. Health and Immunity | 健康与免疫

Health is a state of physical, mental and social well-being. Diseases can be caused by pathogens (communicable) or by genetic, lifestyle or environmental factors (non-communicable).

健康是身体、心理和社会幸福的状态。疾病可由病原体引起（传染性）或由遗传、生活方式或环境因素引起（非传染性）。

The immune system defends the body against pathogens. White blood cells can engulf microbes, produce antibodies, or release antitoxins to neutralise poisons.

免疫系统保护身体免受病原体侵害。白细胞可以吞噬微生物、产生抗体或释放抗毒素来中和毒素。

Vaccination introduces a harmless form of a pathogen to stimulate the production of memory cells. This provides immunity so that if the real pathogen invades, the response is faster and stronger.

疫苗接种引入无害的病原体形式，刺激记忆细胞的产生。这提供了免疫力，因此如果真正的病原体入侵，反应会更快更强。

Antibiotics can kill bacteria but have no effect on viruses. It is important to complete the full course of antibiotics to prevent antibiotic resistance.

抗生素可以杀死细菌，但对病毒无效。完成整个抗生素疗程很重要，以防止抗生素耐药性的产生。

Hygiene practices such as hand washing, safe food preparation, and vaccination programmes are crucial in preventing the spread of infectious diseases.

洗手、安全食品制备和疫苗接种等卫生措施对于预防传染病传播至关重要。

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6. Ecosystems and Food Chains | 生态系统与食物链

An ecosystem is a community of living organisms interacting with each other and their non-living environment. Habitats provide organisms with food, shelter and a place to breed.

生态系统是生物群落与其非生物环境相互作用的统一体。栖息地为生物提供食物、住所和繁殖场所。

Food chains show the transfer of energy from one organism to another. They always start with a producer (usually a green plant) that uses sunlight to make food via photosynthesis.

食物链显示能量从一个生物体转移到另一个生物体。它们总是从生产者（通常是绿色植物）开始，这些生产者利用阳光通过光合作用制造食物。

A typical food chain includes: producer → primary consumer → secondary consumer → tertiary consumer. Arrows represent the direction of energy flow.

一个典型的食物链包括：生产者 → 初级消费者 → 次级消费者 → 三级消费者。箭头代表能量流动的方向。

Food webs are more realistic models showing interconnected food chains in an ecosystem. The removal or addition of one species can affect many others.

食物网是显示生态系统中相互连接的食物链的更真实模型。一个物种的消失或增加会影响许多其他物种。

Predators are animals that kill and eat other animals (prey). In predator-prey cycles, the population sizes rise and fall in a repeating pattern.

捕食者是杀死并吃掉其他动物（猎物）的动物。在捕食者-猎物循环中，种群数量以重复模式上升和下降。

Environmental changes, such as temperature and rainfall, can alter habitats and may lead to the migration or extinction of species.

环境变化，如温度和降雨量，会改变栖息地，并可能导致物种迁徙或灭绝。

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7. Photosynthesis and Plant Transport | 光合作用与植物运输

Photosynthesis is the process by which green plants make their own food using light energy. It takes place in chloroplasts, which contain the green pigment chlorophyll.

光合作用是绿色植物利用光能制造自身食物的过程。它发生在含有绿色色素叶绿素的叶绿体中。

The word equation for photosynthesis is: carbon dioxide + water → glucose + oxygen, in the presence of light and chlorophyll.

光合作用的文字方程式是：二氧化碳 + 水 → 葡萄糖 + 氧气，在光和叶绿素存在下进行。

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Plants use the glucose produced for respiration, to make cellulose for cell walls, to make starch for storage, and to make proteins (with the help of nitrate ions from the soil).

植物利用产生的葡萄糖进行呼吸、制造细胞壁的纤维素、形成储存的淀粉以及（借助土壤中的硝酸根离子）制造蛋白质。

Plants have two transport systems: xylem vessels carry water and dissolved minerals from the roots up to the leaves; phloem tubes carry dissolved sugars (translocation) from the leaves to the rest of the plant.

植物有两个运输系统：木质部导管将水和溶解的矿物质从根部向上运输到叶片；韧皮部管将溶解的糖（运输作用）从叶片输送到植物其他部分。

The transpiration stream is the movement of water from roots to leaves, driven by evaporation from leaf stomata. Stomata are surrounded by guard cells that control their opening and closing.

蒸腾流是水从根部到叶片的运动，由叶片气孔的蒸发驱动。气孔由保卫细胞包围，控制其开闭。

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8. Respiration and Energy | 呼吸与能量

Respiration is the process by which cells release energy from glucose. It happens continuously in all living cells and is not the same as breathing (ventilation).

呼吸是细胞从葡萄糖中释放能量的过程。它在所有活细胞中持续进行，与呼吸（通气）不同。

Aerobic respiration requires oxygen and produces a large amount of energy. The word equation: glucose + oxygen → carbon dioxide + water (+ energy).

有氧呼吸需要氧气并产生大量能量。文字方程式：葡萄糖 + 氧气 → 二氧化碳 + 水（+ 能量）。

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O (+ energy)

Anaerobic respiration occurs when oxygen is insufficient. In human muscles, it converts glucose into lactic acid, releasing much less energy.

无氧呼吸发生在氧气不足时。在人体肌肉中，它将葡萄糖转化为乳酸，释放的能量少得多。

Glucose → Lactic acid (+ some energy)

In yeast and some plants, anaerobic respiration produces ethanol and carbon dioxide – this is called fermentation and is used in baking and brewing.

在酵母和一些植物中，无氧呼吸产生乙醇和二氧化碳——这称为发酵，用于烘焙和酿造。

Energy released during respiration is used for vital life processes such as muscle contraction, maintaining body temperature, active transport, and cell division.

呼吸释放的能量用于维持生命过程，如肌肉收缩、维持体温、主动运输和细胞分裂。

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9. Microorganisms and Disease | 微生物与疾病

Microorganisms, or microbes, are tiny living things that can only be seen with a microscope. The main groups are bacteria, viruses, fungi and protoctists.

微生物是只有在显微镜下才能看到的微小生物。主要的类群有细菌、病毒、真菌和原生生物。

Bacteria are single-celled organisms without a nucleus. Some are harmful pathogens, but many are useful in processes such as decomposition and yoghurt production.

细菌是没有细胞核的单细胞生物。有些是致病的有害菌，但许多在分解和酸奶生产等过程中是有益的。

Viruses are much smaller than bacteria and can only reproduce inside living host cells. They cause diseases such as the common cold, influenza and measles.

病毒比细菌小得多，只能生活在活宿主细胞内。它们引起普通感冒、流感和麻疹等疾病。

Pathogens spread through direct contact, airborne droplets, contaminated food or water, and vectors such as insects. Preventing transmission relies on hygiene, clean water, pest control and vaccination.

病原体通过直接接触、空气飞沫、受污染的食物或水以及昆虫等媒介传播。防止传播依赖卫生、清洁水源、害虫控制和疫苗接种。

An experiment to investigate the growth of microorganisms can be done by inoculating agar plates and incubating at a safe temperature (25 °C in schools). Aseptic technique is essential to avoid contamination.

可以通过接种琼脂平板并在安全温度（学校中使用 25 °C）下培养来研究微生物的生长。无菌技术对于避免污染至关重要。

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10. Classification of Living Things | 生物分类

Living organisms are grouped into five kingdoms: Animals, Plants, Fungi, Prokaryotes (bacteria) and Protoctists. Classification is based on shared characteristics and evolutionary relationships.

生物分为五个界：动物界、植物界、真菌界、原核生物界（细菌）和原生生物界。分类基于共同特征和进化关系。

Within each kingdom, organisms are further divided into phylum, class, order, family, genus and species. The smallest group is the species – organisms that can interbreed to produce fertile offspring.

在每个界内，生物进一步分为门、纲、目、科、属、种。最小的分类群是物种——能相互交配并产生可育后代的一群生物。

Binomial naming gives each species a two-part Latin name, e.g. Homo sapiens for humans. The first name is the genus and the second is the species.

双名法指定每个物种一个由两部分组成的拉丁名，例如人类的 Homo sapiens。第一部分是属名，第二部分是种名。

Vertebrates (animals with backbones) are classified into five groups: mammals, birds, reptiles, amphibians and fish. Each group has distinct features such as body covering and method of reproduction.

脊椎动物（有脊骨的动物）分为五类：哺乳动物、鸟类、爬行动物、两栖动物和鱼类。每组都有独特特征，如体表覆盖物和生殖方式。

• Mammals: hair/fur, give birth to live young, produce milk.
• Birds: feathers, lay eggs with hard shells, beaks.
• Reptiles: dry scales, lay leathery eggs.
• Amphibians: moist skin, lay jelly-coated eggs in water.
• Fish: scales, gills, lay eggs in water (usually).

• 哺乳动物：毛发/毛皮，胎生，产奶。
• 鸟类：羽毛，产硬壳卵，有喙。
• 爬行动物：干燥的鳞片，产革质卵。
• 两栖动物：湿润皮肤，水中产胶质卵。
• 鱼类：鳞片，鳃，通常水中产卵。

Classification helps scientists understand biodiversity and evolutionary links. Dichotomous keys use a series of yes/no questions to help identify unknown organisms.

分类帮助科学家理解生物多样性和进化联系。二分叉检索表使用一系列是/否问题来帮助识别

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