Case Studies in Biology: Real-World Practice | 生物学案例分析实战演练

📚 Case Studies in Biology: Real-World Practice | 生物学案例分析实战演练

Welcome to a set of real-world biology case studies, carefully designed for Year 8 WJEC students. Each scenario presents data, an observation or an experiment that challenges you to apply your understanding of key concepts. By working through these cases, you will sharpen your analytical skills and see how classroom biology connects to everyday life.

欢迎来到这套为 WJEC 八年级学生精心准备的生物学案例研究。每个案例都给出一个真实场景、一组数据或一个实验，考验你对核心概念的理解和运用。通过这些练习，你将锻炼分析能力，体会课堂生物学与日常生活的联系。

1. Case 1: Scurvy on a Ship – Vitamin C Deficiency | 案例1：船上坏血病——维生素C缺乏

In the 18th century, a ship’s crew began suffering from bleeding gums, slow-healing wounds and widespread bruising. The ship’s doctor recorded that the sailors had eaten only salted meat and biscuits for many months, with no fresh fruit or vegetables. He suspected a link between diet and their illness.

18世纪，一艘船的船员开始出现牙龈出血、伤口愈合缓慢和大面积瘀伤。船医记录道，水手们数月只吃咸肉和饼干，没有新鲜水果或蔬菜。他怀疑饮食与疾病之间有关联。

These symptoms are classic signs of scurvy, a deficiency disease caused by a lack of vitamin C. Vitamin C is essential for making collagen – a protein that strengthens blood vessel walls, skin and gums. Without enough collagen, tissues become weak and fragile, leading to the problems the sailors experienced.

这些症状是坏血病的典型表现，这是一种由缺乏维生素C引起的营养缺乏病。维生素C对于合成胶原蛋白至关重要——胶原蛋白能增强血管壁、皮肤和牙龈。没有足够的胶原蛋白，组织就变得脆弱，导致水手们遭遇的问题。

To prevent scurvy, sailors were eventually supplied with citrus fruits such as lemons and limes, which are naturally rich in vitamin C. Today, a balanced diet containing fresh fruit and vegetables provides this vital nutrient and keeps deficiency diseases at bay.

为了预防坏血病，水手们最终获得了柠檬和酸橙等柑橘类水果，它们天然富含维生素C。如今，包含新鲜水果和蔬菜的均衡饮食提供了这种必需营养素，使营养缺乏病不再发生。

2. Case 2: Investigating Enzyme Action – Temperature and Protease | 案例2：探究酶的作用——温度与蛋白酶

A student added the enzyme protease to a cloudy suspension of milk powder at four different temperatures. She timed how long it took for each mixture to turn clear. The protease breaks down the milk protein into smaller, soluble molecules, so clearing time is an inverse measure of enzyme activity.

一位学生在四个不同温度下向浑浊的奶粉悬浊液中加入蛋白酶，并记录各混合物变澄清所需的时间。蛋白酶将牛奶蛋白质分解为较小的可溶分子，因此澄清时间可以反向反映酶的活性。

The fastest clearing occurred at 50 °C, which suggests this is near the enzyme’s optimum temperature. At this point, enzyme and substrate molecules collide most successfully. At 70 °C the time increased sharply because the enzyme’s shape was permanently changed – it had denatured – and could no longer bind to its substrate efficiently.

在50 °C时澄清最快，表明这接近该酶的最适温度。此时酶与底物分子的有效碰撞最频繁。在70 °C时时间急剧增加，因为酶的形状发生了永久性改变——它已变性——无法再高效地与底物结合。

When the milk protein is intact, the large particles scatter light, giving a cloudy appearance. As protease digests the protein into amino acids, the particles become too small to scatter much light, and the solution clears. This simple visual change makes the experiment easy to follow.

当牛奶蛋白质完整时，大颗粒散射光线，呈现浑浊外观。当蛋白酶将蛋白质消化成氨基酸后，颗粒变得太小，不能散射较多光线，溶液便澄清。这一简单的视觉变化使实验易于观察。

3. Case 3: Photosynthesis in Pondweed – Light Intensity Test | 案例3：水草光合作用——光照强度测试

A sprig of pondweed was placed in a beaker of water to which sodium hydrogencarbonate had been added to provide carbon dioxide. The number of oxygen bubbles released per minute was recorded when the lamp was placed at different distances from the beaker.

一枝水草放在装有水的烧杯中，并加入碳酸氢钠以提供二氧化碳。当灯放置在距烧杯不同距离时，记录每分钟释放的氧气气泡数。

As the lamp was moved closer (increasing light intensity), the bubble count rose steadily. This shows that light energy limits the rate of photosynthesis under these conditions. The word equation summarising photosynthesis is:

随着灯靠近（光照强度增加），气泡数稳步上升。这表明在这些条件下，光能限制了光合作用速率。光合作用的文字方程式为：

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

To make it a fair test, the temperature and carbon dioxide supply were kept constant, so only the independent variable (light intensity) was changed. The bubbles contain mainly oxygen, a product of photolysis during the light-dependent reactions.

为了确保公平实验，温度和二氧化碳供应保持恒定，因此只改变了自变量（光照强度）。气泡主要含氧气，是光反应中光解的产物。

4. Case 4: Respiration in Germinating Peas – Measuring Heat Release | 案例4：发芽豌豆的呼吸作用——释放热量的测量

Soaked, germinating pea seeds were placed in a vacuum flask fitted with a thermometer. Another flask held boiled (dead) pea seeds as a control. Both flasks were sealed and left for 24 hours. The temperature in the flask with germinating seeds rose by 3 &

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

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