📚 Year 7 SQA Science: Core Knowledge Review | Year 7 SQA 科学：核心知识点梳理
Welcome to this comprehensive guide covering the key knowledge points in Year 7 SQA Science. This article is designed to help you review and consolidate what you have learned about cells, body systems, substances, forces, energy, electricity, and more. Follow along to strengthen your understanding and prepare for assessments.
欢迎阅读这篇 Year 7 SQA 科学核心知识点梳理指南。本文旨在帮助你复习和巩固有关细胞、身体系统、物质、力、能量、电等方面的知识。跟随本文，加深理解，为评估做好准备。
1. Cells and Living Things | 细胞与生物
All living organisms are made up of cells, which are the basic building blocks of life. Plant and animal cells share some common features but also have important differences.
所有生物体都由细胞构成，细胞是生命的基本积木。植物细胞和动物细胞有一些共同特征，但也存在重要区别。
Both plant and animal cells have a cell membrane that controls what enters and leaves, a nucleus containing genetic material, and cytoplasm where chemical reactions occur. Plant cells also have a rigid cell wall made of cellulose, a large central vacuole for storage, and chloroplasts for photosynthesis.
植物和动物细胞都有细胞膜，控制物质进出；都有细胞核，含有遗传物质；都有细胞质，进行化学反应。植物细胞还有由纤维素构成的坚硬细胞壁、用于储存的大液泡和进行光合作用的叶绿体。
Microorganisms such as bacteria, fungi, and viruses are also important living things. Some are useful, like those used to make yoghurt, while others can cause diseases.
微生物如细菌、真菌和病毒也是重要的生物。有些是有益的，例如用于制作酸奶的微生物，而另一些则会引发疾病。
Cells are organised into tissues, tissues into organs, and organs into organ systems. For example, muscle cells form muscle tissue, which makes up the heart, an organ that pumps blood.
细胞构成组织，组织构成器官，器官再构成器官系统。例如，肌肉细胞构成肌肉组织，肌肉组织构成心脏，心脏是泵血的器官。
2. Body Systems in Action | 工作中的身体系统
The human body has several organ systems that work together to keep us alive. The digestive system breaks down food into small molecules that can be absorbed into the bloodstream.
人体有多个器官系统，它们协同工作以维持生命。消化系统将食物分解成能被吸收到血液中的小分子。
Food travels through the mouth, oesophagus, stomach, small intestine, large intestine, and rectum. Enzymes help break down carbohydrates, proteins, and fats. Villi in the small intestine increase the surface area for absorption.
食物经过口腔、食道、胃、小肠、大肠和直肠。酶帮助分解碳水化合物、蛋白质和脂肪。小肠内的绒毛增大了吸收的表面积。
The respiratory system brings oxygen into the body and removes carbon dioxide. Air enters through the nose or mouth, passes down the trachea, into the bronchi, and finally into the alveoli where gas exchange happens.
呼吸系统将氧气带入体内并排出二氧化碳。空气通过鼻腔或口腔进入，向下经过气管，进入支气管，最终进入肺泡进行气体交换。
The circulatory system, made up of the heart, blood vessels, and blood, transports oxygen, nutrients, and waste products. The heart pumps blood through arteries, veins, and capillaries.
循环系统由心脏、血管和血液组成，运输氧气、营养物质和废物。心脏通过动脉、静脉和毛细血管泵血。
3. Reproduction and Growth | 生殖与生长
Reproduction is the process by which organisms produce new individuals. In Year 7, you learn about both plant and human reproduction.
生殖是生物产生新个体的过程。在 Year 7，你会学习植物和人类的生殖。
Flowering plants reproduce sexually through pollination and fertilisation. Pollen from the stamen (male part) is transferred to the stigma (female part). After fertilisation, the ovary develops into a fruit containing seeds.
开花植物通过授粉和受精进行有性繁殖。花粉从雄蕊（雄性部分）转移到柱头（雌性部分）。受精后，子房发育成含有种子的果实。
In humans, the male reproductive system produces sperm in the testes, while the female reproductive system releases eggs from the ovaries. Fertilisation usually occurs in the oviduct, and the fertilised egg implants in the uterus to develop into a foetus.
在人类中，男性生殖系统在睾丸中产生精子，女性生殖系统从卵巢释放卵子。受精通常发生在输卵管内，受精卵植入子宫发育成胎儿。
The menstrual cycle prepares the female body for pregnancy, and hormones control the changes during puberty. Growth in multicellular organisms occurs through cell division and specialisation.
月经周期为女性身体怀孕做准备，激素控制青春期期间的变化。多细胞生物的生长通过细胞分裂和分化实现。
4. The Particle Model of Matter | 物质的粒子模型
The particle model helps explain the properties of solids, liquids, and gases. All matter is made up of tiny particles that are constantly moving.
粒子模型有助于解释固体、液体和气体的性质。所有物质都由不断运动的微小粒子构成。
In solids, particles are held tightly together in a regular pattern and only vibrate in place. This gives solids a fixed shape and volume. In liquids, particles are close but can move past each other, so liquids have a fixed volume but take the shape of their container.
在固体中，粒子紧密排列成规则结构，只能在原地振动。这使得固体有固定的形状和体积。在液体中，粒子靠得很近但可以互相滑过，因此液体有固定体积却呈现容器的形状.
In gases, particles are far apart and move randomly at high speeds. Gases have no fixed shape or volume and can be compressed easily. Changes of state, such as melting, freezing, boiling, and condensation, can be explained by changes in particle arrangement and energy.
在气体中，粒子相距很远并高速随机运动。气体没有固定形状或体积，容易被压缩。状态变化，如熔化、凝固、沸腾和凝结，可以用粒子排列和能量的变化来解释。
Diffusion is the movement of particles from a high concentration to a lower concentration. This happens faster in gases than in liquids, and even slower in solids.
扩散是粒子从高浓度区域向低浓度区域移动的过程。气体中扩散最快，液体中较慢，固体中最慢。
5. Elements, Compounds, and Mixtures | 元素、化合物和混合物
Everything is made from about 100 different elements. An element is a pure substance made of only one type of atom. Compounds contain two or more elements chemically bonded together. Mixtures contain two or more substances not chemically combined.
万物都由大约 100 种不同的元素构成。元素是由同一种原子组成的纯物质。化合物包含两种或多种以化学键结合的元素。混合物则包含两种或多种未发生化学结合的物质。
Elements are listed in the Periodic Table. Each element has a symbol, such as O for oxygen, Fe for iron, and Na for sodium. Compounds have formulas showing the ratio of atoms, like H₂O for water and CO₂ for carbon dioxide.
元素列在元素周期表中。每种元素都有一个符号，如 O 代表氧，Fe 代表铁，Na 代表钠。化合物有表示原子比例的化学式，例如水 H₂O，二氧化碳 CO₂。
Mixtures can be separated using physical techniques such as filtration, evaporation, distillation, and chromatography. For example, sand and water can be separated by filtration; salt from salt water by evaporation.
混合物可以用物理方法分离，如过滤、蒸发、蒸馏和色谱。例如，沙子和水可以通过过滤分离；盐水中的盐可以通过蒸发分离。
Air is a mixture of gases, mainly nitrogen (about 78%) and oxygen (about 21%), with small amounts of argon, carbon dioxide, and water vapour.
空气是气体混合物，主要是氮气（约 78%）和氧气（约 21%），还有少量氩气、二氧化碳和水蒸气。
6. Chemical Reactions | 化学反应
A chemical reaction is a process in which new substances are made. Signs of a chemical reaction include colour change, temperature change, gas production, and formation of a precipitate.
化学反应是生成新物质的过程。化学反应的标志包括颜色变化、温度变化、产生气体和生成沉淀。
shows the reactants and products: for example, methane + oxygen → carbon dioxide + water.
反应物是起始物，产物是生成的新物质。文字方程式表示反应物和产物，例如：甲烷 + 氧气 → 二氧化碳 + 水。
A balanced chemical equation uses symbols and formulae. The law of conservation of mass states that the total mass of reactants equals the total mass of products.
配平的化学方程式使用符号和化学式。质量守恒定律表明反应物的总质量等于产物的总质量。
Common reactions include combustion, where a fuel reacts with oxygen to release energy, and oxidation, where a substance gains oxygen. Metals react with acids to produce a salt and hydrogen gas.
常见反应包括燃烧（燃料与氧气反应释放能量）和氧化（物质得到氧气）。金属与酸反应生成盐和氢气。
lt + hydrogen. For example, magnesium + hydrochloric acid → magnesium chloride + hydrogen.
一般方程式：金属 + 酸 → 盐 + 氢气。例如，镁 + 盐酸 → 氯化镁 + 氢气。
7. Forces and Motion | 力与运动
A force is a push or a pull that can change the speed, direction, or shape of an object. Forces are measured in newtons (N) using a force meter.
力是能改变物体速度、方向或形状的推或拉。力用测力计测量，单位是牛顿 (N)。
agnetic force, and electrostatic force. Weight is the force of gravity acting on an object' ulated as weight = mass × gravitational field strength (W = m × g). On Earth, g ≈ 10 N/kg.
接触力包括摩擦力、空气阻力和张力。非接触力包括重力、磁力和静电力。重量是作用在物体质量上的重力，计算为 重量 = 质量 × 重力场强度 (W = m × g)。在地球上，g ≈ 10 N/kg。
Balanced forces result in no change in motion; unbalanced forces cause acceleration, deceleration, or change in direction. Speed is calculated as distance ÷ time. A distance–time graph can show an object's motion.
平衡力不会改变运动状态；非平衡力会导致加速、减速或方向改变。速度 = 距离 ÷ 时间。距离 - 时间图可以展示物体的运动。
Friction can be useful, such as when walking, but it can also cause wear and energy loss. Streamlining reduces air resistance or drag.
摩擦有时有用，比如走路时，但它也会造成磨损和能量损失。流线型设计可以减少空气阻力或拖拽力。
8. Energy Forms and Transfers | 能量形式与转移
Energy is the ability to do work. It exists in many forms, including kinetic, thermal, light, sound, electrical, chemical, and gravitational potential energy. Energy is measured in joules (J).
能量是做功的能力。它存在多种形式，包括动能、热能、光能、声能、电能、化学能和重力势能。能量以焦耳 (J) 为单位测量。
Energy can be transferred from one store to another, but the total amount of energy is always conserved. For example, when you switch on a lamp, electrical energy is transferred into light and thermal energy.
能量可以从一种储存转移到另一种储存，但总能量总是守恒的。例如，当你开灯时，电能转化为光能和热能。
Energy transfers can be represented by Sankey diagrams, which show the proportions of useful and wasted energy. Heat can be transferred by conduction, convection, and radiation. Conduction occurs mainly in solids, convection in liquids and gases, and radiation does not require particles.
能量转移可以用桑基图表示，显示有用能量和浪费能量的比例。热量可以通过传导、对流和辐射传递。传导主要在固体中发生，对流在液体和气体中，辐射不需要粒子。
Renewable energy sources include solar, wind, hydroelectric, and geothermal. Non-renewable sources include fossil fuels and nuclear fuels. Burning fossil fuels releases carbon dioxide, contributing to climate change.
可再生能源包括太阳能、风能、水力和地热。不可再生能源包括化石燃料和核燃料。燃烧化石燃料会释放二氧化碳，导致气候变化。
9. Electricity and Circuits | 电与电路
Electric current is the flow of electric charge around a circuit. Current is measured in amperes (amps, A) using an ammeter connected in series. Voltage is the 'push' that drives the current and is measured in volts (V) with a voltmeter connected in parallel.
电流是电荷在电路中的流动。电流以安培 (A) 为单位，用串联的安培计测量。电压是驱动电流的“推力”，以伏特 (V) 为单位，用并联的电压表测量。
A simple circuit needs a power supply (such as a cell or battery), conducting wires, and a component like a bulb or motor. A switch can open or close the circuit. In a series circuit, there is only one path for the current; if one component fails, the whole circuit stops.
一个简单的电路需要电源（如电池）、导线和一个元件如灯泡或马达。开关可以接通或断开电路。在串联电路中，电流只有一条通路；如果一个元件故障，整个电路停止工作。
In a parallel circuit, there are multiple paths. Each component gets the full voltage, and if one branch breaks, the others still work. Resistance is a measure of how much a component opposes the flow of current, measured in ohms (Ω).
在并联电路中，有多条通路。每个元件获得全电压，若一个支路断开，其他支路仍可工作。电阻是衡量元件阻碍电流流动的程度的量，单位是欧姆 (Ω)。
Conductors, like metals, allow electricity to flow easily; insulators, like plastic and rubber, do not. Static electricity is a build-up of electric charge on a surface, often caused by friction.
导体，如金属，容易让电流通过；绝缘体，如塑料和橡胶，则阻碍电流。静电是表面上电荷的积累，通常由摩擦引起。
10. Earth and Space Science | 地球与空间科学
Earth is a rocky planet with three main layers: the crust, the mantle, and the core. The crust is thin and made of solid rock; the mantle is semi-solid and very hot; the core is made of iron and nickel, with a liquid outer core and solid inner core.
地球是一颗岩石行星，有三个主要圈层：地壳、地幔和地核。地壳很薄，由坚硬的岩石组成；地幔是半固态且非常炽热；地核由铁和镍构成，外核是液态的，内核是固态的。
The rock cycle describes how rocks change between igneous, sedimentary, and metamorphic forms. Igneous rocks form from cooled magma or lava; sedimentary rocks form from compressed layers of sediment; metamorphic rocks form when existing rocks are changed by heat and pressure.
岩石循环描述了火成岩、沉积岩和变质岩之间的转化。火成岩由冷却的岩浆或熔岩形成；沉积岩由沉积层压缩而成；变质岩是原有岩石在热和压力下变质形成的。
The solar system consists of the Sun, eight planets, their moons, and other bodies like asteroids and comets. The order of planets from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Earth's tilt on its axis causes the seasons, and the Moon's orbit causes phases.
太阳系由太阳、八大行星、它们的卫星以及小行星和彗星等天体组成。行星距太阳由近及远：水星、金星、地球、火星、木星、土星、天王星、海王星。地球自转轴的倾斜导致四季变化，月球轨道产生了月相。
Day and night are caused by Earth's rotation on its axis once every 24 hours. The apparent movement of the Sun and stars is due to this rotation.
昼夜由地球每 24 小时自转一圈引起。太阳和恒星的视运动正是这种自转的结果。
11. Scientific Inquiry and Skills | 科学探究与技能
In Year 7 Science, you develop practical skills through investigations. A hypothesis is a testable prediction about a relationship between variables. An independent variable is the one you change; a dependent variable is the one you measure; controlled variables are kept the same.
在 Year 7 科学中，你通过探究活动培养实践技能。假设是对变量之间关系的可检验预测。自变量是你改变的变量；因变量是你测量的变量；控制变量是保持不变的变量。
When presenting results, use tables with clear headings and units. Graphs, such as bar charts or line graphs, help visualise patterns. A line of best fit can show a trend. Evaluate your investigation by discussing limitations and suggesting improvements.
展示结果时，使用有清晰标题和单位的表格。图表，如条形图或折线图，有助于可视化模式。最佳拟合线可以显示趋势。通过讨论局限性并提出改进建议来评估探究活动。
Health and safety are crucial: always wear safety goggles, tie back long hair, and follow your teacher's instructions. Understand common hazard symbols for flammable, corrosive, and toxic substances.
健康与安全至关重要：始终佩戴护目镜，把长发扎起来，并听从老师的指导。了解易燃、腐蚀性和有毒物质的常见危险标志。
Accurate measurements use appropriate instruments such as thermometers, stopwatches, rulers, and measuring cylinders. Taking repeat readings and calculating a mean increases reliability.
准确测量需要使用合适的仪器，如温度计、秒表、尺子和量筒。多次读数并计算平均值可提高可靠性。
Published by TutorHao | Science Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图