📚 Core Knowledge Review for Year 10 Edexcel Biology | Year 10 Edexcel 生物：核心知识点梳理
In Year 10 Edexcel Biology, students build a solid foundation by exploring the fundamental principles that govern living organisms. From the microscopic structure of cells to the complex interactions within ecosystems, this stage equips learners with essential concepts for their IGCSE journey. Understanding these core topics not only prepares you for examinations but also nurtures a lifelong appreciation for the science of life.
在 Year 10 Edexcel 生物课程中，学生通过探索支配生命体的基本原理来打下坚实的基础。从细胞的微观结构到生态系统中复杂的相互作用，这一阶段为学习者的 IGCSE 之旅装备了必要的概念。理解这些核心主题不仅为考试做好准备，还培养了对生命科学的终身热爱。
1. Cell Structure and Function | 细胞结构与功能
All living organisms are composed of cells, which can be classified as prokaryotic or eukaryotic. Eukaryotic cells, found in plants, animals, and fungi, contain a distinct nucleus and membrane-bound organelles such as mitochondria and chloroplasts. In contrast, prokaryotic cells, such as bacteria, lack a true nucleus and have a simpler structure with genetic material floating in the cytoplasm as a single circular chromosome.
所有生物体都由细胞组成，可分为原核细胞和真核细胞。真核细胞存在于植物、动物和真菌中，含有明显的细胞核以及线粒体、叶绿体等膜结合细胞器。相反，原核细胞（如细菌）没有真正的细胞核，结构更简单，遗传物质以单个环状染色体的形式漂浮在细胞质中。
Key organelles each have specialised functions. Mitochondria are the site of aerobic respiration, releasing energy in the form of ATP. Ribosomes, either free in the cytoplasm or attached to the rough endoplasmic reticulum, synthesise proteins. In plant cells, chloroplasts absorb light energy for photosynthesis, and a large permanent vacuole maintains turgor pressure. The cell membrane, present in all cells, controls the movement of substances in and out via a partially permeable barrier.
关键的细胞器各有专门的功能。线粒体是有氧呼吸的场所，以 ATP 的形式释放能量。核糖体游离于细胞质中或附着在粗面内质网上，合成蛋白质。在植物细胞中，叶绿体吸收光能进行光合作用，而一个大的中央液泡维持膨压。所有细胞都有的细胞膜，作为选择透过性屏障控制物质的进出。
Specialised cells are adapted to perform specific roles. For example, red blood cells lack a nucleus to maximise space for haemoglobin, enabling efficient oxygen transport. Root hair cells possess elongated projections to increase surface area for water and mineral absorption. Sperm cells have a streamlined head and a tail (flagellum) for motility, while nerve cells are long and insulated to rapidly transmit electrical impulses.
特化的细胞适应于执行特定的角色。例如，红细胞没有细胞核，以最大化容纳血红蛋白的空间，实现高效的氧气运输。根毛细胞具有伸长的突起，以增大吸收水分和矿物质的表面积。精子细胞具有流线型的头部和尾部（鞭毛）以利于运动，而神经细胞则长且绝缘，以快速传递电冲动。
2. Biological Molecules | 生物分子
Carbohydrates, proteins, and lipids are the three main macronutrients essential for life. Carbohydrates, made of carbon, hydrogen, and oxygen, include simple sugars like glucose and complex polysaccharides like starch and glycogen. Proteins are composed of amino acid chains folded into specific shapes, while lipids (fats and oils) consist of glycerol and three fatty acids. Each group provides energy and structural components for cells.
碳水化合物、蛋白质和脂质是对生命至关重要的三大宏量营养素。碳水化合物由碳、氢、氧组成，包括简单的糖类（如葡萄糖）和复杂的多糖（如淀粉和糖原）。蛋白质由氨基酸链折叠成特定形状构成，而脂质（脂肪和油）由甘油和三个脂肪酸组成。每一类都为细胞提供能量和结构成分。
Food tests are practical skills for identifying these molecules. Benedict’s solution turns brick-red when heated with reducing sugars like glucose. Iodine solution changes from yellow-brown to blue-black in the presence of starch. The biuret test for proteins involves adding sodium hydroxide and copper(II) sulfate, producing a purple colour if peptide bonds are present. For lipids, the emulsion test with ethanol and water yields a cloudy white layer.
食物测试是鉴定这些分子的实践技能。本尼迪克特试剂与还原糖（如葡萄糖）加热后变成砖红色。碘液在淀粉存在时从黄棕色变为蓝黑色。检测蛋白质的双缩脲试验涉及加入氢氧化钠和硫酸铜，如果存在肽键则产生紫色。对于脂质，用乙醇和水进行的乳剂测试会产生浑浊的白色层。
DNA is the molecule of inheritance, a double helix made of nucleotides. Each nucleotide consists of a phosphate group, a deoxyribose sugar, and a nitrogenous base (adenine, thymine, cytosine, or guanine). Base pairing rules – A with T and C with G – are crucial for replication and protein synthesis. The sequence of bases codes for the order of amino acids in proteins, determining an organism’s traits.
DNA 是遗传的分子，一个由核苷酸组成的双螺旋结构。每个核苷酸由一个磷酸基团、一个脱氧核糖和一个含氮碱基（腺嘌呤、胸腺嘧啶、胞嘧啶或鸟嘌呤）组成。碱基配对规则——A与T，C与G——对复制和蛋白质合成至关重要。碱基序列编码蛋白质中氨基酸的顺序，决定了生物体的性状。
3. Enzymes | 酶
Enzymes are biological catalysts, mostly proteins, that speed up metabolic reactions without being consumed. They work by lowering the activation energy required for a reaction. Each enzyme has an active site with a specific shape that is complementary to its substrate, forming an enzyme-substrate complex. This ‘lock and key’ model ensures high specificity, meaning each enzyme catalyses only one type of reaction.
酶是生物催化剂，大多是蛋白质，能加速代谢反应而自身不被消耗。它们通过降低反应所需的活化能来发挥作用。每种酶都有一个特定形状的活性位点，与其底物互补，形成酶-底物复合物。这种“锁与钥匙”模型确保了高度专一性，意味着每种酶只催化一种类型的反应。
Environmental conditions significantly affect enzyme activity. Temperature first increases kinetic energy and collisions, leading to a higher reaction rate up to an optimum point. Beyond this, the enzyme denatures as the active site’s shape is permanently altered. Similarly, each enzyme has an optimum pH; deviation from this pH disrupts ionic bonds, reducing activity. Denaturation is often irreversible, causing a loss of function.
环境条件显著影响酶活性。温度首先增加动能和碰撞频率，使反应速率升高直至最佳点。超过此点，酶变性，活性位点的形状永久改变。同样，每种酶都有最适 pH；偏离此 pH 会破坏离子键，降低活性。变性通常是不可逆的，导致功能丧失。
Enzymes play vital roles in digestion. Amylase breaks down starch into maltose in the mouth and small intestine. Proteases, such as pepsin in the stomach, hydrolyse proteins into amino acids. Lipases convert lipids into fatty acids and glycerol, a process aided by bile salts which emulsify fats to increase surface area. These enzymes work under specific pH conditions optimised for their locations.
酶在消化中起着重要作用。淀粉酶在口腔和小肠中将淀粉分解为麦芽糖。蛋白酶（如胃中的胃蛋白酶）将蛋白质水解为氨基酸。脂肪酶将脂质转化为脂肪酸和甘油，这一过程由胆汁盐辅助，胆汁盐乳化脂肪以增加表面积。这些酶在适合其位置的最佳 pH 条件下工作。
4. Movement of Substances | 物质的运动
Diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration, down a concentration gradient. It is a passive process, requiring no energy. In living organisms, oxygen and carbon dioxide diffuse across alveolar and capillary walls during gas exchange. The rate of diffusion is increased by a larger surface area, a steeper concentration gradient, higher temperature, and shorter diffusion distance.
扩散是粒子从高浓度区域向低浓度区域的净运动，沿浓度梯度进行。这是一个被动过程，不需要能量。在生物体中，氧气和二氧化碳在气体交换过程中通过肺泡和毛细血管壁扩散。扩散速率因更大的表面积、更陡的浓度梯度、更高的温度和更短的扩散距离而增加。
Osmosis is a special case of diffusion involving water molecules moving through a partially permeable membrane from a dilute (high water potential) to a more concentrated (low water potential) solution. In plant cells, water entering by osmosis causes the cell to become turgid, supporting the plant. In animal cells, a lack of a cell wall can cause lysis if too much water enters or crenation if too much water leaves.
渗透作用是扩散的一种特殊情况，涉及水分子通过选择透过性膜从稀溶液（高水势）向较浓溶液（低水势）移动。在植物细胞中，水通过渗透进入使细胞变得硬挺，支撑植物。在动物细胞中，由于没有细胞壁，如果过多的水进入会导致裂解，过多的水离开则会导致皱缩。
Active transport is the movement of substances against a concentration gradient, from low to high concentration. This process requires energy in the form of ATP and is mediated by carrier proteins in the cell membrane. An important example is the uptake of mineral ions by root hair cells from the soil, where concentrations are lower than inside the cell. Active transport allows cells to absorb necessary nutrients even when the gradient is unfavourable.
主动运输是物质逆浓度梯度（从低浓度到高浓度）的运动。此过程需要 ATP 形式的能量，并由细胞膜中的载体蛋白介导。一个重要的例子是根毛细胞从土壤中吸收矿物质离子，土壤中的浓度低于细胞内。主动运输使细胞即使在梯度不利的情况下也能吸收必需的营养物质。
5. Photosynthesis and Plant Nutrition | 光合作用与植物营养
Photosynthesis is the process by which green plants convert light energy into chemical energy in the form of glucose. The overall word equation is: carbon dioxide + water → glucose + oxygen, in the presence of light and chlorophyll. The balanced chemical equation is:
光合作用是绿色植物在光和叶绿体存在下，将光能转化为葡萄糖形式化学能的过程。总文字方程为：二氧化碳 + 水 → 葡萄糖 + 氧气。配平的化学方程式为：
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
This endothermic reaction occurs in the chloroplasts, using light energy absorbed by chlorophyll. The rate of photosynthesis is affected by limiting factors: light intensity, carbon dioxide concentration, and temperature. As one factor increases, the rate rises until another factor becomes limiting. At very high temperatures, enzymes such as rubisco denature, causing a sharp decline in the rate.
这个吸热反应发生在叶绿体中，利用叶绿素吸收的光能。光合作用的速率受限制因素影响：光照强度、二氧化碳浓度和温度。随着一个因素的增加，速率上升，直到另一个因素成为限制因素。在极高温度下，如 Rubisco 等酶会变性，导致速率急剧下降。
Plants require mineral ions absorbed from the soil. Nitrate ions are needed for the synthesis of amino acids and proteins; a deficiency causes stunted growth and yellowing of leaves. Magnesium ions are a central component of chlorophyll; lack of magnesium leads to chlorosis, where leaves turn yellow and photosynthesis is reduced. Phosphate ions are essential for making DNA, cell membranes, and ATP.
植物需要从土壤中吸收矿物质离子。硝酸根离子用于合成氨基酸和蛋白质；缺乏会导致生长受阻和叶片发黄。镁离子是叶绿素的核心成分；缺镁会导致萎黄病，叶片变黄，光合作用减弱。磷酸根离子对于制造 DNA、细胞膜和 ATP 必不可少。
6. Human Nutrition and Digestion | 人体营养与消化
A balanced diet includes carbohydrates, proteins, lipids, vitamins, minerals, water, and dietary fibre. Each component has specific functions: carbohydrates supply immediate energy, proteins are for growth and repair, and lipids provide long-term energy storage and insulation. Vitamins like vitamin C prevent scurvy, while minerals like calcium strengthen bones. Dietary fibre aids peristalsis and prevents constipation.
均衡的饮食包括碳水化合物、蛋白质、脂质、维生素、矿物质、水和膳食纤维。每种成分都有特定功能：碳水化合物提供即时能量，蛋白质用于生长和修复，脂质提供长期能量储存和绝缘作用。维生素如维生素 C 预防坏血病，而矿物质如钙强化骨骼。膳食纤维帮助肠道蠕动并预防便秘。
The human digestive system consists of the alimentary canal and accessory organs. Food is mechanically broken down by chewing in the mouth, where salivary amylase begins starch digestion. The oesophagus uses peristalsis to push food to the stomach, where gastric juice containing hydrochloric acid and pepsin digests proteins. The small intestine is the main site for chemical digestion and absorption, with villi increasing surface area.
人体消化系统由消化道和附属器官组成。食物在口腔中通过咀嚼进行机械性分解，唾液淀粉酶开始消化淀粉。食道通过蠕动将食物推入胃，胃液含有盐酸和胃蛋白酶，消化蛋白质。小肠是化学消化和吸收的主要场所，绒毛增加了表面积。
The role of villi is crucial: each villus has a thin epithelium, a dense capillary network, and a lacteal (lymph vessel). This structure allows efficient absorption of digested products. Glucose and amino acids pass into blood capillaries, while fatty acids and glycerol are absorbed into the lacteal as chylomicrons. The large intestine absorbs water and forms faeces.
绒毛的作用至关重要：每根绒毛有薄的上皮层、密集的毛细血管网和一根乳糜管（淋巴管）。这种结构能够高效吸收消化产物。葡萄糖和氨基酸进入毛细血管，而脂肪酸和甘油以乳糜微粒的形式被吸收到乳糜管中。大肠吸收水分并形成粪便。
7. Respiration | 呼吸作用
Respiration is the process of releasing energy from glucose, occurring in every living cell. It is not synonymous with breathing. Aerobic respiration requires oxygen and releases a large amount of energy:
呼吸作用是从葡萄糖释放能量的过程，发生在每个活细胞中。它不等同于呼吸（换气）。有氧呼吸需要氧气，释放大量能量：
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O (+ ATP)
The energy released is used for various life processes, including muscle contraction, active transport, cell division, and maintaining a constant body temperature in mammals.
释放的能量用于各种生命活动，包括肌肉收缩、主动运输、细胞分裂以及哺乳动物维持恒定体温。
Anaerobic respiration occurs when oxygen is limited. In animal cells, such as during strenuous exercise, glucose is partially broken down into lactic acid, releasing a small amount of energy. In yeast and plants, anaerobic respiration produces ethanol and carbon dioxide – a process known as fermentation. Both types of anaerobic respiration yield only 2 ATP molecules per glucose molecule, far less than the 36-38 ATP from aerobic respiration.
当氧气有限时，进行无氧呼吸。在动物细胞中，例如剧烈运动时，葡萄糖部分分解为乳酸，释放少量能量。在酵母和植物中，无氧呼吸产生乙醇和二氧化碳——这一过程称为发酵。两种无氧呼吸每分子葡萄糖只产生 2 个 ATP 分子，远少于有氧呼吸产生的 36-38 个 ATP。
The accumulation of lactic acid in muscles causes fatigue and oxygen debt. During recovery, oxygen debt is repaid by continued deep breathing, which supplies extra oxygen to convert lactic acid back into glucose in the liver, or oxidise it to carbon dioxide and water. This is why breathing rate and heart rate remain elevated after intense exercise.
肌肉中乳酸的积累会导致疲劳和氧债。在恢复过程中，通过持续深呼吸偿还氧债，提供额外的氧气，将乳酸在肝脏中转回葡萄糖，或将其氧化成二氧化碳和水。这就是剧烈运动后呼吸频率和心率仍然升高的原因。
8. Gas Exchange and Breathing | 气体交换与呼吸
The human respiratory system is designed to maximise gas exchange. Air enters through the trachea, which branches into bronchi, bronchioles, and finally alveoli – tiny air sacs surrounded by capillaries. The intercostal muscles and diaphragm work together to ventilate the lungs. During inhalation, the diaphragm contracts and flattens, the ribcage rises, increasing thoracic volume and decreasing pressure, drawing air in.
人体呼吸系统旨在最大化气体交换。空气通过气管进入，气管分支成支气管、细支气管，最后到达肺泡——被毛细血管包围的微小气囊。肋间肌和膈肌协同工作以进行肺换气。吸气时，膈肌收缩并变平，肋骨上升，增加胸腔容积，降低压力，将空气吸入。
Gas exchange at the alveoli relies on diffusion. Oxygen diffuses from the alveolar air space into the blood, where it binds to haemoglobin in red blood cells. Carbon dioxide diffuses in the opposite direction. The alveoli are adapted for this function: they provide a large surface area, a thin single-cell epithelium, a rich blood supply, and a steep concentration gradient maintained by ventilation and blood flow.
肺泡处的气体交换依赖于扩散。氧气从肺泡腔扩散到血液中，与红细胞中的血红蛋白结合。二氧化碳朝相反方向扩散。肺泡适应了这一功能：它们提供了大的表面积、单层薄上皮细胞、丰富的血液供应，以及通过通气和血流维持的陡峭浓度梯度。
The effects of smoking on the respiratory system are profound. Tar damages cilia, reducing the clearance of mucus and pathogens, leading to chronic bronchitis. Hot smoke and chemicals destroy alveolar walls, causing emphysema and reducing surface area for gas exchange. Carcinogens in tobacco smoke can cause uncontrolled cell division, leading to lung cancer. Carbon monoxide binds irreversibly to haemoglobin, reducing the blood’s oxygen-carrying capacity.
吸烟对呼吸系统的影响深远。焦油损害纤毛，减少黏液和病原体的清除，导致慢性支气管炎。热烟和化学物质破坏肺泡壁，导致肺气肿并减少气体交换的表面积。烟草烟雾中的致癌物可引起不受控制的细胞分裂，导致肺癌。一氧化碳不可逆地与血红蛋白结合，降低血液的携氧能力。
9. Transport in Plants and Animals | 动植物中的运输
In plants, xylem and phloem form the vascular tissue. Xylem transports water and dissolved mineral ions from the roots to the leaves in a one-way flow. This movement is driven by transpiration, where evaporation from leaves creates a tension that pulls the water column upwards – the transpiration stream. Xylem vessels are dead cells with thickened lignin walls, providing structural support.
在植物中，木质部和韧皮部构成维管组织。木质部以单向流将水和溶解的矿物质离子从根运输到叶。这种运动由蒸腾作用驱动，叶片蒸发产生张力拉动水柱向上——即蒸腾流。木质部导管是死细胞，具有加厚的木质化壁，提供结构支撑。
Phloem transports sucrose and amino acids from sources (where they are produced, like leaves) to sinks (where they are used or stored, like roots and fruits). This process, called translocation, requires energy and occurs in both directions. Companion cells load sucrose into sieve tube elements, which lack nuclei and rely on companion cells for metabolic functions.
韧皮部将蔗糖和氨基酸从源（产生它们的部位，如叶片）运输到库（使用或储存它们的部位，如根和果实）。这一过程称为转运，需要能量，并双向进行。伴胞将蔗糖装载到筛管分子中，筛管分子没有细胞核，依赖伴胞进行代谢功能。
The human circulatory system consists of the heart, blood vessels, and blood. The heart is a double pump; the right side pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the body. Arteries carry blood away from the heart under high pressure, with thick muscular walls. Veins return blood at lower pressure, containing valves to prevent backflow. Capillaries are microscopic, one-cell-thick vessels where exchange occurs.
人体循环系统由心脏、血管和血液组成。心脏是一个双泵；右侧将缺氧血泵入肺，左侧将富氧血泵入全身。动脉在高压下将血液带离心脏，具有厚厚的肌肉壁。静脉在较低压力下将血液送回，含有瓣膜以防止回流。毛细血管是微观的、单细胞厚的血管，物质交换在此进行。
10. Excretion and Homeostasis | 排泄与稳态
Excretion is the removal of metabolic waste products from the body. The main excretory organs are the lungs (carbon dioxide), the kidneys (urea and excess water/salts), and the skin (sweat). The urinary system’s key organ, the kidney, filters blood via nephrons. Each nephron consists of a glomerulus and Bowman’s capsule for ultrafiltration, followed by the tubule where selective reabsorption occurs.
排泄是将代谢废物从体内清除的过程。主要的排泄器官是肺（二氧化碳）、肾脏（尿素和多余的水/盐）和皮肤（汗液）。泌尿系统的关键器官肾脏通过肾单位过滤血液。每个肾单位包括用于超滤的肾小球和鲍曼氏囊，随后是进行选择性重吸收的肾小管。
In ultrafiltration, high pressure forces water, urea, ions, and glucose out of the glomerulus into the Bowman’s capsule, forming filtrate. Larger molecules like proteins and blood cells remain in the blood. In the proximal convoluted tubule, all glucose, some water, and many ions are selectively reabsorbed back into the blood by active transport and diffusion. The loop of Henle and collecting duct fine-tune water balance under ADH control.
在超滤过程中，高压迫使水、尿素、离子和葡萄糖从肾小球进入鲍曼氏囊，形成滤液。较大的分子如蛋白质和血细胞留在血液中。在近端曲折小管中，所有的葡萄糖、部分水和许多离子通过主动运输和扩散被选择性地重吸收回血液。亨氏袢和集合管在抗利尿激素（ADH）控制下微调水平衡。
Homeostasis is the maintenance of a constant internal environment. Key examples include thermoregulation (sweating, shivering, vasodilation/constriction) and blood glucose regulation. Insulin and glucagon, produced by the pancreas, work antagonistically: insulin lowers blood glucose by promoting glycogen storage, while glucagon raises it by stimulating glycogen breakdown. Type 1 diabetes results from the destruction of insulin-producing beta cells.
稳态是维持恒定内环境的过程。关键例子包括体温调节（出汗、颤抖、血管舒张/收缩）和血糖调节。胰腺分泌的胰岛素和胰高血糖素相互作用：胰岛素通过促进糖原储存降低血糖，而胰高血糖素通过刺激糖原分解升高血糖。1 型糖尿病是由产生胰岛素的 β 细胞被破坏引起的。
11. Coordination and Response | 协调与反应
The nervous system allows rapid, short-lived responses to stimuli. A reflex arc is the simplest pathway: receptor → sensory neurone → relay neurone (in spinal cord or brain) → motor neurone → effector. Reflexes such as the withdrawal from a hot object are involuntary and protective. Synapses between neurones use chemical neurotransmitters to transmit impulses, and drugs can interfere with this transmission.
神经系统能够对刺激做出快速而短暂的反应。反射弧是最简单的通路：感受器→感觉神经元→中间神经元（在脊髓或脑中）→运动神经元→效应器。如从热物体缩手等反射是非自主的、保护性的。神经元之间的突触使用化学神经递质传递冲动，药物可以干扰这种传递。
The endocrine system, in contrast, uses hormones – chemical messengers transported in the blood – to bring about slower, longer-lasting effects. Key glands include the pituitary (master gland), thyroid (thyroxine, regulating metabolism), pancreas (insulin and glucagon), adrenal glands (adrenaline for ‘fight or flight’), and ovaries/testes (sex hormones). Adrenaline increases heart rate, dilates pupils, and boosts glucose release for instant energy.
相比之下，内分泌系统利用激素——通过血液运输的化学信使——产生较慢但更持久的效果。主要腺体包括垂体（主腺）、甲状腺（甲状腺素，调节代谢）、胰腺（胰岛素和胰高血糖素）、肾上腺（肾上腺素，用于“战斗或逃跑”）以及卵巢/睾丸（性激素）。肾上腺素增加心率、放大瞳孔、促进葡萄糖释放以提供即时能量。
Plant responses, known as tropisms, are directional growth movements. Phototropism (growth towards light) is controlled by the plant hormone auxin. Auxin accumulates on the shaded side of a shoot, causing cells to elongate more, bending the shoot towards the light. Gravitropism (response to gravity) ensures roots grow downwards. Commercial use of plant hormones includes rooting powders and weedkillers.
植物的反应，即向性，是定向的生长运动。向光性（向光生长）由植物激素生长素控制。生长素在芽的背光面聚集，导致细胞伸长更多，使芽弯向光。向地性（对重力的反应）确保根向下生长。植物激素的商业用途包括生根粉和除草剂。
12. Reproduction and Inheritance | 生殖与遗传
Asexual reproduction produces genetically identical offspring (clones) from one parent via mitosis. It is fast and efficient but lacks genetic variation. Sexual reproduction involves the fusion of male and female gametes during fertilisation, producing offspring with a mix of traits from both parents. Gametes are haploid (n=23 in humans), formed by meiosis, which introduces variation through independent assortment and crossing over.
无性生殖通过有丝分裂从一个亲本产生遗传上相同的后代（克隆）。它快速高效，但缺乏遗传变异。有性生殖涉及受精过程中雄性和雌性配子的融合，产生的后代具有双亲特征的混合。配子是单倍体（人类 n=23），通过减数分裂形成，该过程通过独立分配和交叉互换引入变异。
The basic principles of inheritance were discovered by Gregor Mendel. Genes are sections of DNA that code for proteins. Alleles are different forms of the same gene, which can be dominant or recessive. A monohybrid cross between two heterozygous parents (e.g., Tt × Tt) yields a 3:1 phenotypic ratio if dominance is complete. Genetic diagrams like Punnett squares help predict possible genotypes and phenotypes.
遗传的基本原理由格里高尔·孟德尔发现。基因是 DNA 上编码蛋白质的片段。等位基因是同一基因的不同形式，可以是显性或隐性。若为完全显性，两个杂合亲本（如 Tt × Tt）的单基因杂交会产生 3:1 的表型比。庞纳特方格等遗传图解有助于预测可能的基因型和表型。
Some inherited disorders include cystic fibrosis (caused by a recessive allele) and Huntington’s disease (caused by a dominant allele). Sex-linked traits, such as red-green colour blindness, are carried on the X chromosome, often affecting males more frequently because they have only one X. Understanding inheritance patterns is crucial for genetic counselling and predicting the risk of passing on diseases.
一些遗传性疾病包括囊性纤维化（由隐性等位基因引起）和亨廷顿舞蹈症（由显性等位基因引起）。伴性性状，如红绿色盲，由 X 染色体携带，通常更多影响男性，因为他们只有一条 X 染色体。理解遗传模式对于遗传咨询和预测疾病遗传风险至关重要。
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