Year 10 Eduqas Biology: Practical Skills & Exam Essentials | Year 10 Eduqas 生物：实验技能与考试要点

📚 Year 10 Eduqas Biology: Practical Skills & Exam Essentials | Year 10 Eduqas 生物：实验技能与考试要点

Practical work is at the heart of the Eduqas GCSE Biology specification. In Year 10, you will undertake a series of required practicals that not only deepen your understanding of scientific concepts but also develop essential laboratory skills. Exam questions will test your ability to describe methods, identify variables, analyse data, and evaluate procedures. Mastering these hands-on techniques and understanding the underlying principles will give you confidence in both the written paper and practical endorsement. This guide highlights the key practicals, from microscopy and food tests to osmosis and sampling, with clear points to help you revise effectively.

实验工作是 Eduqas GCSE 生物学大纲的核心。在 Year 10，你将完成一系列必修实验，这些实验不仅能加深你对科学概念的理解，还会培养关键的实验技能。考试题目会考察你描述方法、识别变量、分析数据和评价实验步骤的能力。掌握这些动手技能并理解其背后的原理，将使你在笔试和实践评估中都信心十足。本指南重点梳理了显微镜使用、食物测试、渗透作用及生态取样等关键实验，配以清晰的要点，助你高效复习。

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1. Using a Light Microscope | 使用光学显微镜

Always carry the microscope with both hands — one holding the arm and the other supporting the base — to prevent damage or accidents.

始终用双手搬运显微镜，一手握住镜臂，另一手托住底座，以防损坏或发生事故。

Start viewing with the lowest power objective lens (usually ×4) to locate the specimen, then carefully rotate the nosepiece to higher magnifications.

先用低倍物镜（通常 ×4）寻找标本，然后小心旋转转换器切换至更高倍镜。

Use the coarse focus knob first with low power to bring the image into approximate focus; switch to the fine focus knob for sharp detail. Never use coarse focus with a high-power objective as it can crack the coverslip and damage the lens.

低倍镜下先用粗准焦螺旋调至大致清晰，再用细准焦螺旋精细对焦；高倍镜下切勿使用粗准焦螺旋，以免压碎盖玻片并损坏物镜。

Total magnification = eyepiece lens magnification × objective lens magnification. For example, with ×10 eyepiece and ×40 objective, total magnification is ×400.

Total Magnification = Eyepiece Magnification × Objective Magnification

总放大倍数 = 目镜放大倍数 × 物镜放大倍数。例如，×10 目镜配合 ×40 物镜，总放大倍数为 ×400。

Adjust the diaphragm and mirror (or built-in lamp) to optimise light intensity. Too much light can wash out transparent specimens; too little makes details invisible.

调节光圈和反光镜（或内置光源）以优化光线强度。光线过强会使透明标本泛白，光线太弱又看不清细节。

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2. Making Accurate Biological Drawings | 制作准确的生物绘图

Use a sharp HB pencil only — never use a pen, coloured pencils or shading. Draw clear, continuous outlines without sketching.

只使用削尖的 HB 铅笔，绝不可用钢笔、彩色铅笔或阴影。绘制清晰、连续的轮廓，不要用草图断线。

The drawing should occupy at least half the available space on a plain sheet; do not add background scenery.

绘图应至少占空白纸页可用空间的一半，不可添加背景景象。

Every structure labelled must have a straight, horizontal label line drawn with a ruler. Label lines must not cross.

每个标注结构必须用直尺画出笔直、水平的指示线，且指示线不可交叉。

Write labels in pencil to the right of the drawing. Include a title that states the specimen and the magnification, e.g. ‘Onion epidermis cells ×100’.

用铅笔在图右侧写出标注。标题需注明标本名称与放大倍数，例如“洋葱表皮细胞 ×100”。

Do not add arrows or circles on the drawing itself; use label lines outside the drawing to point to structures.

不要在绘图上添加箭头或圆圈；应在图外使用指示线指向结构。

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3. Food Tests for Biological Molecules | 食物中的生物分子测试

Below is a summary of the main food tests required by Eduqas:

以下是 Eduqas 要求掌握的主要食物测试总结：

Test	Reagent(s)	Positive Result	Colour Change
Reducing sugars	Benedict’s solution (blue)	Brick-red precipitate	Blue → green/yellow → brick-red
Starch	Iodine solution (brown)	Blue-black colour	Brown → blue-black
Protein	Biuret reagent (blue)	Violet/purple colour	Blue → violet
Lipids (fats)	Sudan III stain (or ethanol emulsion test)	Red-stained oil layer (or milky emulsion)	Colourless fat → distinct red layer

The Benedict’s test requires heating in a water bath at ≥80 °C for approximately 5 minutes. Use a test-tube holder and point the open end away from people.

本尼迪克特测试需在 ≥80 °C 水浴中加热约 5 分钟。使用试管夹并让管口朝向无人处。

For solid samples, first crush the food and mix with distilled water; for protein testing, sodium hydroxide is added dropwise before copper sulfate. Safety goggles must be worn.

对于固体样本，先碾碎并用蒸馏水混合；蛋白质检测需先滴加氢氧化钠再滴加硫酸铜。必须佩戴防护镜。

Iodine test can be performed directly on a solid piece of food; a few drops of iodine solution are enough to show a blue-black colour for starch.

碘液测试可直接滴在固体食物上；数滴碘液即可使淀粉呈现蓝黑色。

Benedict’s test is semi-quantitative — the colour sequence (blue → green → yellow → orange → brick-red) gives an approximate indication of the concentration of reducing sugar.

本尼迪克特测试属于半定量测试——颜色变化序列（蓝 → 绿 → 黄 → 橙 → 砖红）可粗略反映还原糖的浓度。

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4. Investigating Enzyme Activity | 探究酶活性

The classic practical uses amylase enzyme and starch solution. Mix amylase with buffered starch at a given pH, and every 30 seconds remove a drop to test with iodine on a spotting tile.

经典实验使用淀粉酶和淀粉溶液。在某一 pH 的缓冲淀粉液中加入淀粉酶，每隔 30 秒取一滴加到点样板上用碘液测试。

The time taken for the iodine to stop turning blue-black (indicating all starch has been broken down) is recorded. The shorter the time, the faster the rate of reaction.

记录碘液不再变为蓝黑色（表明淀粉全部被分解）所需时间。时间越短，反应速率越快。

Rate of Reaction ∝ 1 / Time

反应速率 ∝ 1/时间

Repeat the experiment at different pH values (e.g. pH 3,5,7,9,11) to determine the optimum pH for amylase. Keep temperature constant using a water bath at around 30 °C.

在不同 pH 值（如 pH 3、5、7、9、11）下重复实验，以确定淀粉酶的最适 pH。使用 30 °C 左右的水浴保持温度恒定。

The independent variable is the pH, the dependent variable is the time (or rate). Control variables include enzyme concentration, starch concentration and volume of solutions.

自变量是 pH，因变量是时间（或速率）。控制变量包括酶浓度、淀粉浓度和溶液体积。

Always measure the pH with indicator paper or a pH meter; prepare buffer solutions carefully. At extremes of pH the enzyme can denature, so the reaction may not go to completion.

务必使用 pH 试纸或 pH 计测量 pH 值；小心配制缓冲液。在极端 pH 下酶可能变性，反应可能难以完成。

Safety: avoid skin contact with buffer solutions; some buffers are irritant. Wash hands after handling starch or iodine, which can stain.

安全事项：避免缓冲液接触皮肤，某些缓冲液具刺激性。处理淀粉或碘液后洗手，碘液会染色。

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5. Osmosis in Potato Tissue | 马铃薯组织的渗透作用

Cut uniform cylinders of potato using a cork borer and trim them to equal length (e.g. 4 cm). Blot dry to remove surface water, then measure the initial mass of each piece.

用打孔器切取均匀的马铃薯圆柱，修整至等长（如 4 cm）。用滤纸吸干表面水分，然后称量每段的初始质量。

Place potato cylinders into test tubes with different concentrations of sucrose solution (e.g. 0.0, 0.2, 0.4, 0.6, 0.8, 1.0 mol dm⁻³). Make sure the tissue is fully submerged.

将马铃薯圆柱放入装有不同浓度蔗糖溶液（如 0.0、0.2、0.4、0.6、0.8、1.0 mol dm⁻³）的试管中，确保组织完全浸没。

Leave for a standard time (e.g. 30 minutes), then remove, blot gently and reweigh. Calculate the change in mass and the percentage change.

放置一定时间（如 30 分钟）后取出，轻轻吸干水分并再次称量。计算质量变化及质量变化百分比。

Percentage Change = (Final Mass − Initial Mass) / Initial Mass × 100%

质量变化百分比 = (最终质量 − 初始质量) / 初始质量 × 100%

Plot a graph of % change in mass against sucrose concentration. The point where the line crosses 0% change gives the water potential of the potato tissue (isotonic point).

绘制质量变化百分比与蔗糖浓度的关系图。曲线与 0% 变化线的交点即为马铃薯组织的水势（等渗点）。

A negative % change indicates net water loss (hypertonic solution); a positive % change indicates net water gain (hypotonic solution).

负百分比变化表示净失水（高渗溶液），正百分比变化表示净吸水（低渗溶液）。

Control variables: length and diameter of cylinders, volume of solution, temperature, and type of potato. All should be kept the same except the sucrose concentration.

控制变量：圆柱长度与直径、溶液体积、温度、马铃薯品种。除蔗糖浓度外，其他条件均应保持一致。

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6. Light Intensity and Photosynthesis | 光照强度与光合作用

Use fresh pondweed such as Elodea in a beaker of water, with a sodium hydrogencarbonate solution as a source of carbon dioxide (0.1% – 0.2% added).

使用新鲜水草如伊乐藻，置于盛水的烧杯中，加入 0.1%–0.2% 的碳酸氢钠溶液作为二氧化碳来源。

Position a lamp at a measured distance (e.g. 10 cm) from the plant. After a few minutes’ equilibration, count the number of oxygen bubbles released per minute (or collect the gas in a measuring cylinder).

将灯放置在距植物一定距离处（如 10 cm）。平衡数分钟后，计数每分钟释出的氧气气泡数（或用带刻度的试管收集气体）。

Vary the distance of the lamp (e.g. 10, 20, 30, 40, 50 cm) to change light intensity. Light intensity decreases with the square of the distance:

改变灯的距离（如 10、20、30、40、50 cm）以改变光照强度。光照强度随距离的平方反比下降：

Light Intensity ∝ 1 / Distance²

光照强度 ∝ 1 / 距离²

Measure temperature before and after; place a heat shield (transparent screen) between lamp and beaker to reduce heating effects, keeping temperature constant.

实验前后测量温度；在灯与烧杯之间放置透明隔热屏，减少加热效应，保持温度恒定。

Count bubbles at each distance at least three times and calculate a mean. Rate of photosynthesis (bubbles per minute) is the dependent variable; distance (or light intensity) is the independent variable.

每个距离至少计数三次，计算平均值。光合作用速率（每分钟气泡数）为因变量；距离（或光照强度）为自变量。

If counting bubbles, use a cut end of pondweed facing the light; cut stem at an angle to create a fresh surface for oxygen release.

如果采用气泡计数法，让水草的切端朝向光源；将茎斜切以形成新鲜切面，有利于氧气逸出。

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7. Sampling Techniques: Quadrats and Transects | 取样技术：样方与样线

To estimate population size in a uniform habitat, use a random sampling strategy with a quadrat. Generate random coordinates to avoid bias.

在均匀生境中估算种群大小时，采用样方随机取样法。生成随机坐标以避免主观偏差。

Place the quadrat at each random point, count the number of individuals (or estimate percentage cover) of the target species. Calculate the mean per quadrat, then multiply by the total area.

将样方放在每个随机点上，计数目标物种的个体数（或估算覆盖百分比）。计算每个样方的平均值，再乘以总面积，即可估算种群总数。

For studying distribution along an environmental gradient (e.g. from seashore to inland), use a transect line. Place a quadrat at regular intervals along the line.

研究沿环境梯度（如从海岸到内陆）的分布时，使用样线。沿样线等间距放置样方。

A belt transect can be used by placing quadrats continuously along the line; this shows how abundance and community composition change with the gradient.

带状样带法可将样方沿样线连续放置，以显示丰度和群落组成如何随梯度变化。

Record data in tables and plot bar charts or kite diagrams for distribution. Always repeat measurements where possible and calculate means.

将数据记录在表格中，并绘制柱形图或风筝图展示分布。尽可能重复测量并计算平均值。

Ethical considerations: minimise trampling, avoid damaging rare species, and return any overturned stones or logs to their original positions.

道德考量：尽量减少踩踏，避免破坏稀有物种，将翻起的石头或原木恢复原位。

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8. Investigating Anaerobic Respiration in Yeast | 探究酵母的无氧呼吸

Mix a yeast suspension with glucose solution in a test tube. Carefully add a layer of liquid paraffin on top to prevent oxygen from dissolving into the mixture.

将酵母悬液与葡萄糖溶液在试管中混合。小心地在液面上加一层液体石蜡，以阻止氧气溶入混合物。

Set up a delivery tube leading from the test tube to another test tube containing limewater (or attach a small balloon over the top to collect carbon dioxide).

搭建导气管，将产生的气体通入另一支装有石灰水的试管（或在试管口套上小气球收集二氧化碳）。

Place the apparatus in a water bath at a controlled temperature (e.g. 30 °C, 40 °C). Observe the limewater turning milky or measure the height of foam produced over a fixed time.

将装置放入控温的水浴中（例如 30 °C、40 °C）。观察石灰水变浑浊，或测量固定时间内产生的泡沫高度。

The rate of respiration can be assessed by the volume of CO₂ produced (using a gas syringe or measuring foam). Plot a graph of foam height against time for different temperatures.

呼吸速率可通过 CO₂ 产生量评估（用气体注射器或测量泡沫高度）。绘制不同温度下泡沫高度随时间的变化图。

Control variables: concentration and volume of yeast, concentration and volume of glucose, pH, and temperature (except when investigating temperature).

控制变量：酵母浓度及体积、葡萄糖浓度及体积、pH 值以及温度（研究温度影响时除外）。

Safety: yeast is a potential allergen

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