Year 7 CAIE Biology: Unit Test Mock Paper Review | 七年级 CAIE 生物：单元测试模拟卷解析

📚 Year 7 CAIE Biology: Unit Test Mock Paper Review | 七年级 CAIE 生物：单元测试模拟卷解析

Welcome to our Year 7 CAIE Biology Unit Test Mock Paper Review. This article presents typical exam-style questions and provides clear, step-by-step explanations. Working through these mock items will help you consolidate essential knowledge, sharpen your exam technique, and boost your confidence for the real assessment. Each question targets a key topic from the CAIE Year 7 curriculum, and the paired English-Chinese analysis ensures you fully understand the concepts.

欢迎阅读我们的七年级 CAIE 生物单元测试模拟卷解析。本文呈现典型的考试风格题目，并提供清晰的逐步解释。通过这些模拟题目，你可以巩固必要的知识，提高考试技巧，并为实际评估建立信心。每道题都针对 CAIE 七年级课程中的一个关键主题，配对的中英文解析确保你完全理解这些概念。

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1. Cells and Microscopes | 细胞与显微镜

Question: A student observed a plant cell under a light microscope and labelled structures A (cell wall), B (nucleus) and C (chloroplast). Explain the function of two of these parts. The microscope eyepiece magnification is ×10 and the objective magnification is ×40. Calculate the total magnification and state the formula.

题目：一名学生在光学显微镜下观察了一个植物细胞，并标注了结构A（细胞壁）、B（细胞核）和C（叶绿体）。解释其中任意两个部分的功能。显微镜目镜放大倍数为 ×10，物镜放大倍数为 ×40。计算总放大倍数并写出公式。

Let us analyse the cell components first. The cell wall is a rigid outer layer made of cellulose; it provides structural support and protection, helping the plant cell maintain a fixed shape.

我们先分析细胞成分。细胞壁是由纤维素构成的坚硬外层；它提供结构支持和保护，帮助植物细胞保持固定形状。

The nucleus is often called the control centre of the cell. It contains the genetic material (DNA) and regulates all cellular activities, including growth, metabolism, and reproduction.

细胞核常被称为细胞的控制中心。它包含遗传物质（DNA），并调节所有细胞活动，包括生长、代谢和繁殖。

Chloroplasts contain the green pigment chlorophyll and are the sites of photosynthesis, where light energy is converted into chemical energy in the form of glucose.

叶绿体含有绿色色素叶绿素，是光合作用的场所，在这里光能被转化为以葡萄糖形式存在的化学能。

For the microscope calculation, the total magnification is obtained by multiplying the eyepiece lens magnification by the objective lens magnification. Using the formula Total Magnification = Eyepiece × Objective, we substitute the values: 10 × 40 = 400. Hence, the total magnification is ×400.

关于显微镜的计算，总放大倍数由目镜放大倍数乘以物镜放大倍数得出。使用公式 总放大倍数 = 目镜 × 物镜，代入数值：10 × 40 = 400。因此，总放大倍数为 ×400。

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2. Classification of Living Things | 生物的分类

Question: All living organisms are grouped into five kingdoms. List the five kingdoms and give one example for each. Vertebrates are further divided into five classes. Name these classes and identify one distinctive feature for each.

题目：所有生物被分为五个界。列出这五个界，并为每个界举出一个例子。脊椎动物又被分为五个纲。请说出这些纲的名称，并为每个纲指出一个显著特征。

Kingdom Animalia: organisms that are multicellular, heterotrophic (they consume other organisms for food) and lack rigid cell walls. Example: lion.

动物界：多细胞、异养生物（以其他生物为食），并且没有坚硬的细胞壁。例子：狮子。

Kingdom Plantae: multicellular, autotrophic (they produce their own food by photosynthesis) and have cellulose cell walls. Example: sunflower.

植物界：多细胞、自养生物（通过光合作用制造食物），并具有由纤维素组成的细胞壁。例子：向日葵。

Kingdom Fungi: mostly multicellular (except yeast), heterotrophic by absorption, and have cell walls made of chitin. Example: mushroom.

真菌界：大多为多细胞（酵母除外），通过吸收方式异养，细胞壁由几丁质构成。例子：蘑菇。

Kingdom Protista: mainly unicellular eukaryotes that may be autotrophic or heterotrophic. Example: Amoeba.

原生生物界：主要为单细胞真核生物，可以是自养或异养。例子：变形虫。

Kingdom Prokaryotae (Monera): unicellular organisms without a true nucleus; their genetic material floats freely in the cytoplasm. Example: Escherichia coli (bacterium).

原核生物界：没有真正细胞核的单细胞生物；其遗传物质在细胞质中自由存在。例子：大肠杆菌（细菌）。

For vertebrate classes, Fish have gills for breathing and scales covering their body.

关于脊椎动物各纲，鱼类有鳃用于呼吸，身体被鳞片覆盖。

Amphibians, such as frogs, have moist, permeable skin and usually begin life in water before moving onto land.

两栖类，如青蛙，具有湿润可渗透的皮肤，通常先在水中生活后再登陆。

Reptiles have dry, scaly skin and lay leathery eggs on land; they are ectothermic. Example: snake.

爬行类拥有干燥的鳞片皮肤，在陆地上产革质卵；它们是变温动物。例子：蛇。

Birds possess feathers and a beak, and they lay hard-shelled eggs; they are endothermic. Example: eagle.

鸟类具有羽毛和喙，产硬壳卵；它们是恒温动物。例子：鹰。

Mammals have hair or fur, and females produce milk to feed their young. Example: human.

哺乳动物有毛发或毛皮，雌性分泌乳汁哺育幼儿。例子：人类。

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3. Digestive System | 消化系统

Question: Describe the path a cheese sandwich takes through the digestive system. Include the main organs and name the types of enzymes that break down the carbohydrate, protein and fat components in the sandwich.

题目：描述一个奶酪三明治经过消化系统的路径。要包括主要器官，并说出分解三明治中碳水化合物、蛋白质和脂肪成分的酶的类型。

Digestion begins in the mouth where teeth mechanically break the food into smaller pieces and salivary amylase (a carbohydrase) starts breaking down starch into maltose.

消化从口腔开始，牙齿机械地将食物分解成小块，唾液淀粉酶（一种糖酶）开始将淀粉分解为麦芽糖。

The food then moves down the oesophagus by peristalsis, a wave of muscle contractions that pushes the bolus to the stomach.

然后食物通过蠕动沿着食道向下移动，蠕动是一波波肌肉收缩，将食团推向胃部。

In the stomach, the food mixes with gastric juice, which contains hydrochloric acid and protease enzymes (e.g. pepsin) that begin protein digestion. The acid also kills bacteria.

在胃中，食物与胃液混合，胃液含有盐酸和蛋白酶（如胃蛋白酶），开始消化蛋白质。胃酸还能杀死细菌。

After leaving the stomach, the partly digested food enters the small intestine. Here, the pancreas releases carbohydrase, protease and lipase enzymes to further digest the nutrients. The liver produces bile, which is stored in the gall bladder and released into the small intestine to emulsify fats into smaller droplets, aiding lipase action.

离开胃后，部分消化的食物进入小肠。在这里，胰腺释放糖酶、蛋白酶和脂肪酶进一步消化营养物质。肝脏产生胆汁，储存在胆囊中并排入小肠，将脂肪乳化成更小的微滴，有助于脂肪酶的作用。

The small intestine is where most digestion is completed and where the soluble products (glucose, amino acids, fatty acids and glycerol) are absorbed into the bloodstream through the villi.

大部分消化是在小肠中完成的，可溶性产物（葡萄糖、氨基酸、脂肪酸和甘油）通过绒毛吸收进入血液。

Any undigested material moves into the large intestine, where water and minerals are reabsorbed, and the remaining waste is formed into faeces and egested through the anus.

未消化的物质进入大肠，在这里水和矿物质被重新吸收，残留的废物形成粪便并通过肛门排出。

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4. Respiratory System | 呼吸系统

Question: Explain the mechanism of breathing in (inhalation) in humans. Include the roles of the diaphragm and intercostal muscles. Where does gas exchange occur in the lungs, and what gases move in which direction?

题目：解释人体的吸气机制。需包括膈肌和肋间肌的作用。气体交换在肺的何处进行，什么气体向什么方向移动？

During inhalation, the diaphragm contracts and flattens from its dome shape. At the same time, the external intercostal muscles contract, pulling the ribcage upwards and outwards.

在吸气过程中，膈肌收缩并从穹窿状变平。同时，外肋间肌收缩，将胸腔向上向外拉起。

These actions increase the volume of the thoracic (chest) cavity, which decreases the air pressure inside the lungs relative to the atmospheric pressure outside. As a result, air rushes in through the nose or mouth, down the trachea, through the bronchi and bronchioles, and finally into the alveoli.

这些动作增大了胸腔的容积，从而降低了肺内气压，使之低于外界大气压。因此，空气经鼻或口进入，沿气管下行，通过支气管和细支气管，最终进入肺泡。

Gas exchange takes place in the alveoli – tiny air sacs surrounded by a dense network of capillaries. Oxygen diffuses from the alveoli into the blood, where it binds to haemoglobin in red blood cells. Carbon dioxide, a waste product of respiration, diffuses from the blood plasma into the alveoli to be exhaled.

气体交换发生在肺泡——这些是微小的气囊，周围环绕着密集的毛细血管网。氧气从肺泡扩散进入血液，与红细胞中的血红蛋白结合。二氧化碳作为呼吸作用的废弃物，则从血浆扩散到肺泡中被呼出。

Published by TutorHao | Year 7 Biology Revision Series | aleveler.com

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