Year 8 OCR Science: Core Knowledge Checklist | 八年级OCR科学：核心知识点梳理

📚 Year 8 OCR Science: Core Knowledge Checklist | 八年级OCR科学：核心知识点梳理

Welcome to your essential Year 8 OCR Science revision guide. This article covers the key knowledge you need to master across Biology, Chemistry and Physics. Use it to test your understanding and fill any gaps.

欢迎阅读八年级OCR科学核心复习指南。本文涵盖生物、化学和物理中必须掌握的关键知识点。用来自我检测，查漏补缺。

1. Cells and Microscopy | 细胞与显微镜

All living organisms are made of cells. Cells may be eukaryotic (with a nucleus) or prokaryotic (without a nucleus). Animals and plants are eukaryotic; bacteria are prokaryotic.

所有生物都由细胞构成。细胞可分为真核细胞（有细胞核）和原核细胞（无细胞核）。动物和植物是真核生物，细菌是原核生物。

Animal cells contain a cell membrane, cytoplasm, nucleus and mitochondria. Plant cells have the same parts plus a rigid cell wall, a large permanent vacuole and chloroplasts for photosynthesis.

动物细胞含有细胞膜、细胞质、细胞核和线粒体。植物细胞除了这些部分还有坚硬的细胞壁、大液泡和进行光合作用的叶绿体。

Microscopes allow us to see cells. The total magnification is calculated by multiplying the eyepiece lens magnification by the objective lens magnification.

显微镜使我们能观察到细胞。总放大倍率通过目镜放大率乘以物镜放大率计算得出。

Magnification = size of image ÷ size of real object

放大倍率 = 图像大小 ÷ 实物大小。

To use a light microscope correctly, always start with the lowest power objective, use the coarse focus knob first and then the fine focus to get a sharp image.

正确使用光学显微镜时，始终从最低倍物镜开始，先用粗调焦旋钮，再用细调焦旋钮获得清晰图像。

---

2. Human Organ Systems: Breathing and Digestion | 人体器官系统：呼吸与消化

The respiratory system moves air into and out of the body. Air travels through the trachea, bronchi and bronchioles to reach the alveoli, where gas exchange takes place.

呼吸系统将空气吸入和排出身体。空气经过气管、支气管和细支气管到达肺泡，气体交换在此进行。

In the alveoli, oxygen diffuses into the surrounding blood capillaries and carbon dioxide diffuses out into the alveoli to be exhaled. The large surface area of alveoli speeds up diffusion.

在肺泡处，氧气扩散进入周围的毛细血管，二氧化碳扩散出血液进入肺泡被呼出。肺泡巨大的表面积加快了扩散速度。

Inhaled air contains about 21% oxygen and very little carbon dioxide. Exhaled air contains less oxygen (about 16%) and more carbon dioxide, and is saturated with water vapour.

吸入的空气含有约21%的氧气和极少的二氧化碳。呼出的空气含氧较少（约16%），二氧化碳较多，且饱含水蒸气。

Digestion breaks down large, insoluble food molecules into small, soluble molecules that can be absorbed into the bloodstream. Enzymes are biological catalysts that speed up these reactions.

消化将大的、不溶的食物分子分解为小的、可溶的分子，以便被血液吸收。酶是加速这些反应的生物催化剂。

Starch is broken down by carbohydrase (amylase) into glucose. Proteins are broken down by protease into amino acids. Fats (lipids) are broken down by lipase into fatty acids and glycerol.

淀粉被碳水化合物酶（淀粉酶）分解为葡萄糖。蛋白质被蛋白酶分解为氨基酸。脂肪被脂肪酶分解为脂肪酸和甘油。

---

3. Plant Biology: Photosynthesis | 植物生物学：光合作用

Photosynthesis is the process by which plants use light energy to convert carbon dioxide and water into glucose and oxygen. It takes place in the chloroplasts, which contain the green pigment chlorophyll.

光合作用是植物利用光能将二氧化碳和水转化为葡萄糖和氧气的过程。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. Light energy is absorbed by chlorophyll to drive the reaction.

光合作用的文字方程式为：二氧化碳 + 水 → 葡萄糖 + 氧气。叶绿素吸收光能来驱动该反应。

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

平衡符号方程式：6个二氧化碳分子与6个水分子反应生成1个葡萄糖分子和6个氧气分子。

Leaves are adapted for photosynthesis: they are broad and flat, thin for short diffusion distance, have stomata for gas exchange, and contain many chloroplasts packed in the palisade layer.

叶片适应光合作用的结构：宽阔而扁平，薄以减少扩散距离，有气孔进行气体交换，且在栅栏组织中密布大量叶绿体。

Limiting factors that affect the rate of photosynthesis include light intensity, carbon dioxide concentration, and temperature. If any one is in short supply, the rate plateaus.

影响光合作用速率的限制因素包括光照强度、二氧化碳浓度和温度。如果其中任何一个不足，速率都会达到平台期。

---

4. Atoms, Elements and the Periodic Table | 原子、元素与周期表

All matter is made of atoms. An element is a pure substance that contains only one type of atom. Compounds contain two or more different elements chemically combined.

所有物质都由原子构成。元素是只含一种原子的纯物质。化合物含有两种或多种不同元素且通过化学键结合。

The periodic table lists elements in order of increasing atomic number. Vertical columns are called groups; elements in the same group have similar chemical properties. Horizontal rows are periods.

周期表按原子序数递增的顺序排列元素。纵列称为族，同族元素具有相似的化学性质。横排称为周期。

Group 1: alkali metals (e.g. lithium, sodium, potassium) are soft, very reactive and react vigorously with water. Group 7: halogens (e.g. chlorine, bromine) are reactive non-metals. Group 0: noble gases are unreactive.

第1族是碱金属（如锂、钠、钾），质地软、反应性强、与水剧烈反应。第7族是卤素（如氯、溴），为活泼非金属。第0族是稀有气体，很不活泼。

Atoms consist of a central nucleus containing protons and neutrons, surrounded by electrons in shells. The atomic number is the number of protons, which determines the element’s identity.

原子由含质子和中子的中心原子核以及核外分层排布的电子构成。原子序数是质子数，决定了元素的种类。

The mass number is the total number of protons and neutrons in the nucleus. For a neutral atom, the number of electrons equals the number of protons.

质量数是原子核中质子数与中子数之和。对于中性原子，电子数等于质子数。

---

5. Chemical Reactions: Combustion and Oxidation | 化学反应：燃烧与氧化

In a chemical reaction, reactants are transformed into products. Signs of a chemical reaction include a colour change, energy change (heat or light), gas production, or a precipitate forming.

Published by TutorHao | Year 8 Science Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）