Core Knowledge Review for Year 11 Edexcel Biology | Year 11 Edexcel 生物核心知识点梳理

📚 Core Knowledge Review for Year 11 Edexcel Biology | Year 11 Edexcel 生物核心知识点梳理

This article provides a structured review of the key topics in Year 11 Edexcel Biology, covering essential concepts from cell biology to ecology. It is designed to help students consolidate their understanding and prepare effectively for assessments.

本文系统梳理了 Year 11 Edexcel 生物的核心知识点，涵盖从细胞生物学到生态学的基本概念，旨在帮助学生巩固理解并高效备考。

1. Cell Structure and Function | 细胞结构与功能

Eukaryotic cells, such as animal and plant cells, contain a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. The nucleus stores genetic material, the cytoplasm is the site of chemical reactions, the cell membrane controls substance movement, mitochondria release energy via respiration, and ribosomes carry out protein synthesis.

真核细胞（如动物和植物细胞）包含细胞核、细胞质、细胞膜、线粒体和核糖体。细胞核储存遗传物质，细胞质是化学反应的场所，细胞膜控制物质进出，线粒体通过呼吸作用释放能量，核糖体负责蛋白质合成。

Plant cells have additional structures: a rigid cell wall made of cellulose, a large permanent vacuole containing cell sap, and chloroplasts that absorb light energy for photosynthesis. In contrast, prokaryotic cells (e.g. bacteria) lack a nucleus and membrane-bound organelles; their genetic material floats as a single DNA loop in the cytoplasm.

植物细胞有额外的结构：由纤维素构成的坚韧细胞壁、充满细胞液的大液泡以及吸收光能进行光合作用的叶绿体。相反，原核细胞（如细菌）没有细胞核和膜结合细胞器，其遗传物质以单个DNA环的形式漂浮在细胞质中。

Many cells are specialised to perform specific functions. For example, sperm cells have a tail for swimming and many mitochondria for energy; nerve cells are long to carry electrical impulses; root hair cells increase surface area for water and mineral absorption; and xylem vessels are hollow to transport water in plants.

许多细胞特化以执行特定功能。例如，精子细胞有用于游动的尾部和许多提供能量的线粒体；神经细胞很长以传递电脉冲；根毛细胞增大表面积以吸收水分和矿物质；木质部导管中空，用于在植物体内运输水分。

2. Cell Division and Growth | 细胞分裂与生长

The cell cycle includes growth, DNA replication and mitosis. Mitosis produces two genetically identical daughter cells and is used for growth, repair and asexual reproduction. The stages of mitosis are prophase, metaphase, anaphase and telophase, followed by cytokinesis.

细胞周期包括生长、DNA复制和有丝分裂。有丝分裂产生两个遗传上相同的子细胞，用于生长、修复和无性繁殖。有丝分裂的阶段为前期、中期、后期和末期，随后进行胞质分裂。

Stem cells are undifferentiated cells that can divide and develop into specialised cell types. Embryonic stem cells can differentiate into any cell type, while adult stem cells have a more limited potential. In plants, meristem cells act as stem cells, allowing continuous growth at root and shoot tips.

干细胞是未分化的细胞，能分裂并发育成特化的细胞类型。胚胎干细胞可以分化为任何细胞类型，而成体干细胞的潜能较有限。在植物中，分生组织细胞充当干细胞，使根尖和茎尖能够持续生长。

3. Organisation of Living Organisms | 生物体的组织层次

Cells are organised into tissues, organs and organ systems. A tissue is a group of similar cells working together; examples include muscle tissue and xylem tissue. Organs are made of different tissues performing a specific function, such as the leaf or the stomach.

细胞组织形成组织、器官和器官系统。组织是一群相似细胞协同工作的集合，例如肌肉组织和木质部组织。器官由不同组织构成，执行特定功能，如叶或胃。

Organ systems are groups of organs that work together to carry out major functions. The digestive system breaks down and absorbs nutrients; the circulatory system transports substances; the respiratory system exchanges gases; and the reproductive system produces offspring.

器官系统是共同完成主要功能的器官集合。消化系统分解并吸收营养物质；循环系统运输物质；呼吸系统进行气体交换；生殖系统产生后代。

4. The Digestive System and Enzymes | 消化系统与酶

Enzymes are biological catalysts that speed up chemical reactions without being used up. The lock-and-key model describes how the substrate fits into the enzyme’s active site. Enzymes are specific and their activity is affected by temperature and pH; extreme conditions can cause denaturation.

酶是生物催化剂，能加速化学反应而自身不被消耗。锁钥模型描述了底物如何嵌入酶的活性位点。酶具有特异性，其活性受温度和pH影响；极端条件会导致变性。

Digestive enzymes break down large food molecules into smaller absorbable ones. Amylase (produced in salivary glands and pancreas) breaks starch into maltose; proteases (stomach, pancreas) break proteins into amino acids; and lipases (pancreas) break lipids into fatty acids and glycerol. Bile, produced by the liver, emulsifies fats to increase their surface area.

消化酶将大食物分子分解为可吸收的小分子。淀粉酶（由唾液腺和胰腺产生）将淀粉分解为麦芽糖；蛋白酶（胃、胰腺）将蛋白质分解为氨基酸；脂肪酶（胰腺）将脂质分解为脂肪酸和甘油。肝脏产生的胆汁乳化脂肪以增加其表面积。

5. The Circulatory System | 循环系统

The heart is a double pump. Deoxygenated blood enters the right atrium, moves to the right ventricle and is pumped to the lungs. Oxygenated blood returns to the left atrium, enters the left ventricle and is pumped to the body. Valves prevent backflow of blood.

心脏是一个双泵。缺氧血进入右心房，流至右心室并被泵送到肺部。富氧血返回左心房，进入左心室并被泵送到全身。瓣膜防止血液倒流。

Blood vessels include arteries (thick muscular walls, carry blood away from the heart at high pressure), veins (thinner walls, valves, carry blood to the heart at low pressure) and capillaries (one-cell thick, allow exchange of substances). Blood contains red cells (transport oxygen), white cells (defend against pathogens), platelets (clotting) and plasma (transports dissolved substances).

血管包括动脉（厚肌壁，高压将血液带离心脏）、静脉（壁较薄、有瓣膜，低压将血液送回心脏）和毛细血管（单细胞厚，允许物质交换）。血液含有红细胞（运输氧气）、白细胞（抵御病原体）、血小板（凝血）和血浆（运输溶解物质）。

6. Communicable and Non-communicable Diseases | 传染病与非传染病

Communicable diseases are caused by pathogens: viruses (e.g. measles, HIV), bacteria (e.g. Salmonella, Gonorrhoea), fungi (e.g. athlete’s foot) and protists (e.g. malaria). They can be spread by air, water, direct contact or vectors. The body defends itself through physical barriers, phagocytosis and antibody production.

传染病由病原体引起：病毒（如麻疹、HIV）、细菌（如沙门氏菌、淋病）、真菌（如脚癣）和原生生物（如疟疾）。它们可通过空气、水、直接接触或载体传播。人体通过物理屏障、吞噬作用和抗体生成进行防御。

Non-communicable diseases are not infectious. Risk factors include lifestyle (diet, smoking, exercise) and genetics. Coronary heart disease involves narrowing of coronary arteries due to fatty deposits; cancer results from uncontrolled cell division. Correlation does not always indicate causation.

非传染病不具有传染性。风险因素包括生活方式（饮食、吸烟、运动）和遗传。冠心病涉及脂肪沉积导致的冠状动脉狭窄；癌症由细胞分裂失控引起。相关性并不总是表示因果关系。

7. Photosynthesis and Respiration | 光合作用与呼吸作用

Photosynthesis is an endothermic reaction in which plants use light energy to convert carbon dioxide and water into glucose and oxygen. Chlorophyll in chloroplasts captures light. The word and symbol equations are:

光合作用是吸热反应，植物利用光能将二氧化碳和水转化为葡萄糖和氧气。叶绿体中的叶绿素捕获光能。文字和符号方程如下：

Carbon dioxide + water → glucose + oxygen

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Photosynthesis rate is limited by light intensity, carbon dioxide concentration and temperature. At the compensation point, the rates of photosynthesis and respiration are equal.

光合作用速率受光照强度、二氧化碳浓度和温度的限制。在补偿点，光合作用和呼吸作用的速率相等。

Aerobic respiration releases large amounts of energy from glucose using oxygen:

有氧呼吸利用氧气从葡萄糖中释放大量能量：

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

Anaerobic respiration in animals produces lactic acid and releases much less energy; in plants and yeast, it produces ethanol and carbon dioxide. Fermentation is used in bread and alcohol production.

动物体内的无氧呼吸产生乳酸并释放少得多的能量；在植物和酵母中，产生乙醇和二氧化碳。发酵用于面包和酒精生产。

8. The Nervous System and Homeostasis | 神经系统与稳态

Homeostasis maintains a stable internal environment. Key regulated conditions include body temperature, blood glucose level and water balance. The nervous system allows rapid responses to stimuli through reflex arcs.

稳态维持内环境的稳定。主要调节条件包括体温、血糖水平和水分平衡。神经系统通过反射弧对刺激做出快速反应。

A reflex arc involves a stimulus → receptor → sensory neurone → relay neurone (in CNS) → motor neurone → effector → response. Synapses use neurotransmitters to pass impulses between neurones.

反射弧涉及刺激 → 感受器 → 感觉神经元 → 中间神经元（在中枢神经系统） → 运动神经元 → 效应器 → 反应。突触利用神经递质在神经元之间传递冲动。

Thermoregulation involves the hypothalamus and skin. When core temperature rises, vasodilation and sweating increase heat loss; when it falls, vasoconstriction and shivering conserve and generate heat.

体温调节涉及下丘脑和皮肤。当核心温度升高时，血管舒张和出汗增加散热；当温度下降时，血管收缩和颤抖保存并产生热量。

9. Hormonal Coordination | 激素调节

Hormones are chemical messengers produced by endocrine glands and transported in the blood. They have slower, longer-lasting effects compared to nerve impulses. Insulin (from pancreas) lowers blood glucose by converting glucose to glycogen; glucagon raises it by converting glycogen back to glucose.

激素是由内分泌腺产生并通过血液运输的化学信使。与神经冲动相比，它们作用较慢但更持久。胰岛素（来自胰腺）通过将葡萄糖转化为糖原降低血糖；胰高血糖素通过将糖原转化为葡萄糖提高血糖。

Type 1 diabetes is caused by insufficient insulin production; type 2 diabetes involves body cells becoming resistant to insulin. Adrenaline prepares the body for ‘fight or flight’ by increasing heart rate and blood glucose. Thyroid hormones regulate metabolism.

1型糖尿病由胰岛素分泌不足引起；2型糖尿病涉及身体细胞对胰岛素产生抵抗。肾上腺素通过增加心率和血糖使身体做好“战斗或逃跑”准备。甲状腺激素调节新陈代谢。

10. Reproduction and Inheritance | 生殖与遗传

Sexual reproduction involves the fusion of male and female gametes, producing offspring that are genetically varied. Meiosis halves the chromosome number to form gametes. Asexual reproduction produces clones via mitosis and requires only one parent.

有性繁殖涉及雄性和雌性配子的融合，产生遗传上变异的子代。减数分裂使染色体数目减半以形成配子。无性繁殖通过有丝分裂产生克隆，只需一个亲本。

DNA is a double helix polymer containing genes. A gene codes for a specific protein. Alleles are different versions of a gene. Genetic diagrams and Punnett squares predict the probability of inheriting traits. Single-gene crosses illustrate dominant and recessive alleles, with homozygous and heterozygous genotypes.

DNA是包含基因的双螺旋聚合物。一个基因编码一种特定蛋白质。等位基因是同一基因的不同版本。遗传图解和庞纳特方格预测性状遗传的概率。单基因杂交说明显性和隐性等位基因，以及纯合和杂合基因型。

Sex determination in humans: females have XX chromosomes, males have XY. Therefore, the sperm determines the sex of the offspring.

人类的性别决定：女性有XX染色体，男性有XY染色体。因此，精子决定后代的性别。

11. Variation and Evolution | 变异与进化

Variation within a species can be genetic, environmental or both. Mutations are random changes in DNA that can introduce new alleles. Continuous variation (e.g. height) shows a range, while discontinuous variation (e.g. blood group) has distinct categories.

物种内的变异可以是遗传的、环境的或两者兼有。突变是DNA的随机变化，可引入新的等位基因。连续变异（如身高）显示一个范围，而不连续变异（如血型）有明确的类别。

Evolution occurs by natural selection: individuals with advantageous alleles are more likely to survive and reproduce, passing these alleles to offspring. Over many generations, these alleles become more common. Evidence for evolution includes fossils and antibiotic resistance in bacteria.

进化通过自然选择发生：具有有利等位基因的个体更可能存活和繁殖，并将这些等位基因传递给后代。多代之后，这些等位基因变得更常见。进化的证据包括化石和细菌的抗生素耐药性。

Concept / 概念	Explanation / 解释
Selective breeding / 选择育种	Humans breed organisms with desired traits to produce offspring with those traits. / 人类培育具有所需性状的生物，使其后代也具有这些性状。
Genetic engineering / 基因工程	Transferring genes between organisms to introduce desired characteristics. / 将基因在生物体之间转移以引入所需特征。

12. Ecology and Ecosystems | 生态学与生态系统

An ecosystem is the interaction of a community of living organisms with the non-living parts of their environment. Individuals → population → community → ecosystem. Plants are producers; animals are consumers (primary, secondary, tertiary); decomposers break down dead material.

生态系统是生物群落与其环境中的非生物部分之间的相互作用。个体 → 种群 → 群落 → 生态系统。植物是生产者；动物是消费者（初级、次级、三级）；分解者分解死物质。

Food chains show energy flow. Energy is lost at each trophic level, so chains rarely exceed four or five levels. Food webs are more realistic networks of interconnected chains.

食物链显示能量流动。能量在每一营养级都有损失，因此链很少超过四到五个营养级。食物网是相互连接的食物链组成的更现实网络。

Materials cycle through ecosystems. In the carbon cycle, carbon dioxide is fixed by photosynthesis and returned via respiration, combustion and decomposition. Water cycles through evaporation, transpiration, condensation and precipitation. Biodiversity is essential for stable ecosystems; human activities such as deforestation and pollution threaten this balance.

物质在生态系统中循环。在碳循环中，二氧化碳通过光合作用固定，并通过呼吸、燃烧和分解返回。水通过蒸发、蒸腾、冷凝和降水循环。生物多样性对稳定的生态系统至关重要；人类活动如森林砍伐和污染威胁着这一平衡。

Published by TutorHao | Biology Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）

Core Knowledge Review for Year 11 Edexcel Biology | Year 11 Edexcel 生物核心知识点梳理