📚 Year 7 CIE Biology: Key Points for Practical Assessments | Year 7 CIE 生物：实验/实践考核要点
Practical work is the heart of biology. In Year 7, you will learn how to use laboratory equipment safely, make careful observations, record data and begin to design simple experiments. This article covers the key skills you need to succeed in your practical assessments, from using a microscope to presenting results in a graph. Mastering these foundations will not only boost your confidence in the lab but also prepare you for more advanced scientific investigations in the years ahead.
实验操作是生物学的核心。在七年级，你将学习如何安全地使用实验器材、进行细致观察、记录数据，并开始设计简单的实验。本文涵盖了在实践考核中取得成功所需的关键技能，从使用显微镜到用图表展示结果。掌握这些基础不仅能增强你在实验室的信心，也能为你今后更深入的科学探究做好准备。
1. Safety in the Lab | 实验室安全
Always wear safety goggles when handling chemicals, heating substances or working with biological materials such as pond water. Tie back long hair and tuck in loose clothing to prevent accidents.
在处理化学品、加热物质或处理池塘水等生物材料时，请务必佩戴护目镜。将长发扎起，并将宽松的衣物塞好，以防发生意外。
Learn to recognise common hazard symbols: flammable, corrosive, irritant and biohazard. Never taste or smell substances directly; instead, waft the odour towards your nose if instructed.
学会识别常见的危险标志：易燃、腐蚀性、刺激性和生物危害。切勿直接品尝或闻任何物质；如有要求，应用手扇动气味至鼻前。
Always wash your hands after practical work, even if you wore gloves. Report any spillages or breakages to your teacher straight away.
实验结束后务必洗手，即使戴了手套。任何溢出或破损都应立即报告老师。
2. Using a Microscope | 使用显微镜
ive lenses (e.g. ×4, ×10, ×40), stage, stage clips, coarse focus knob and fine focus knob.
光学显微镜可以让你看到细胞和微生物。主要部件有目镜（通常放大10倍）、物镜（如4倍、10倍、40倍）、载物台、压片夹、粗准焦螺旋和细准焦螺旋。
on = eyepiece × objective. Always start with the lowest power objective lens to locate the specimen.
计算总放大倍数时，将目镜放大倍数乘以物镜放大倍数：总放大倍数 = 目镜 × 物镜。始终从最低倍物镜开始，以便找到标本。
When making a wet mount slide, place the specimen in a drop of water on a glass slide, lower a coverslip at a 45° angle to avoid air bubbles, and use a stain like iodine if needed to make structures visible.
制作临时装片时，将标本放在载玻片的水滴中，以45度角缓慢放下盖玻片以避免气泡，必要时使用碘液等染色剂使结构清晰可见。
3. Measuring and Observing | 测量与观察
Accurate measurement is a core skill. Use a ruler to measure the length or width of a leaf in millimetres. Read the scale at eye level and record the unit.
准确测量是一项核心技能。用直尺测量叶片的长度或宽度，单位为毫米。视线与刻度水平，并记录单位。
A measuring cylinder is used to measure liquid volumes. Always read the bottom of the meniscus at eye level. Thermometers should be held in the liquid without touching the container, and readings taken when the liquid stops moving.
量筒用于测量液体体积。始终在视线水平处读取凹液面最低点。温度计应悬在液体中，不接触容器，待液柱停止移动后读数。
Use a stopwatch to time reactions such as how long it takes for starch to disappear when mixed with amylase. Observe colour changes carefully and note the exact time.
使用秒表计时反应，比如淀粉与淀粉酶混合后消失所需的时间。仔细观察颜色变化并记录确切时间。
4. Recording Data | 记录数据
Design a results table before you start the experiment. The table must have clear headings and units, for example 'Temperature (°C)' and 'Number of bubbles per minute'.
实验开始前先设计结果表格。表格必须有清晰的标题和单位，例如“温度（°C）”和“每分钟气泡数量”。
Record readings immediately and clearly. In investigations where you take several measurements of the same condition, capture all repeats and calculate a mean (average). Always check for anomalous results that do not fit the pattern.
立即并清晰地记录读数。在对相同条件进行多次测量的实验中，记录所有重复实验的结果，并计算平均值。时刻检查是否存在不符合规律的异常结果。
If you are measuring plant growth over time, record the height in a table with columns for day and height. Use a consistent number of decimal places to show the precision of your measurements.
如果测量植物生长随时间的变化，在表格中记录天数与高度。使用一致的小数位数，以体现测量精度。
5. Drawing Scientific Diagrams | 绘制科学图表
Biological drawings should be simple, clear and drawn in pencil. Use a sharp HB pencil and unbroken lines. Do not shade or colour in; use stippling (small dots) for darker areas if necessary.
生物绘图应当简洁、清晰，并用铅笔绘制。使用削尖的HB铅笔和不间断的线条。不要涂色或阴影；必要时用点画法（小点）表现深色区域。
encil, and include a title that says what the specimen is and the magnification used, e.g. 'Onion epidermal cells, ×100'.
用直线引出标注，直线需接触被标注的部分。用铅笔水平书写标签，并包括标题，说明标本是什么以及放大倍数，例如“洋葱表皮细胞，×100”。
The drawing should be large enough to show detail but must fit on the page, with labels outside the drawing. Always draw what you actually see, not what you think you should see from a textbook.
绘图需足够大以展示细节，但必须在页面内，标签写在图外部。始终画出你实际观察到的样子，而不是课本上你认为应该看到的样子。
6. Identifying Variables | 识别变量
Every fair test experiment has three types of variables. The independent variable is the one you change deliberately. The dependent variable is what you measure or observe. Control variables are all the factors you keep the same to make the test fair.
每一个公平测试实验都有三种变量。自变量是你有意改变的因素。因变量是你测量或观察的结果。控制变量是为了保证测试公平而保持不变的所有因素。
For example, when testing how light intensity affects photosynthesis in pondweed, the independent variable is the distance of the lamp, the dependent variable is the number of oxygen bubbles produced per minute, and control variables include water temperature, the length of pondweed and the same lamp used.
例如，在测试光强对水草光合作用的影响时，自变量是灯的距离，因变量是每分钟产生的氧气气泡数，控制变量包括水温、水草长度和使用同一盏灯。
You should list the control variables in your experimental plan and suggest ways to keep them constant, such as using a water bath for temperature or the same piece of pondweed for all trials.
你应该在实验计划中列出控制变量，并建议如何使其保持不变，例如使用水浴保持温度，或所有测试使用同一段水草。
7. Planning a Simple Investigation | 设计简单实验
Every investigation begins with a clear aim, written as a sentence starting with 'To investigate...'. You also need a hypothesis, which is a prediction based on scientific knowledge, often written as 'If... then... because...'.
每个探究都始于一个明确的目的，写成以“探究……”开头的句子。你还需要一个假设，即基于科学知识的预测，常写成“如果……那么……因为……”的形式。
Write a step-by-step method that another student could follow. Use numbered steps and include how you will measure results and keep the test fair. Mention any safety precautions needed, such as wearing goggles or avoiding contact with hot water.
写出一步步的方法，让其他同学也能照着做。使用编号步骤，说明如何测量结果并保持测试公平。提及所有必要的安全预防措施，比如戴护目镜或避免接触热水。
Include a list of apparatus and materials. For an experiment on enzyme action, you might need test tubes, a water bath, starch solution, amylase, iodine solution, a spotting tile and a stopwatch.
列出所需的仪器和材料。对于酶作用的实验，你可能需要试管、水浴、淀粉溶液、淀粉酶、碘液、点滴板和秒表。
8. Presenting Results in Tables and Graphs | 用表格和图表展示结果
After collecting data, present it in a well-organised table. The left column usually shows the independent variable and the right column shows the dependent variable. Include units in the headers.
收集数据后，将其呈现在一个组织良好的表格中。左列通常为自变量，右列为因变量。在表头注明单位。
For continuous data, draw a line graph. Mark the independent variable on the x-axis and the dependent variable on the y-axis. Label each axis with the variable and unit, choose a suitable scale that uses more than half the graph paper, and plot points with small crosses.
对于连续数据，绘制折线图。将自变量标在x轴，因变量标在y轴。为每个轴标记变量和单位，选择合适的标度，使图形占据图纸一半以上，并用小叉号标出数据点。
If the data is in categories (e.g. favourite fruit), draw a bar chart. Bars should be of equal width and with spaces between them. Always give your graph a clear title, such as 'Graph showing the effect of temperature on the activity of catalase'.
如果数据属于分类（如最喜欢的水果），则绘制柱状图。柱宽应相等，柱间有间隔。始终给图表一个清晰的标题，例如“显示温度对过氧化氢酶活性影响的图表”。
hange in mass or product ÷ time taken. Show your working and round the answer to an appropriate number of significant figures.
在计算速率时，如反应速率，使用公式：速率 = 质量或产物的变化量 ÷ 所用时间。展示计算过程，并将答案四舍五入到适当的小数位。
9. Making Conclusions from Data | 从数据得出结论
A conclusion states what you found out and relates it back to the original aim and hypothesis. Avoid simply repeating the data; look for patterns, trends or relationships. For instance, 'As temperature increased up to 40°C, the rate of starch break down increased, above 40°C the rate decreased.'
结论说明你发现了什么，并将其与最初的目的和假设联系起来。避免简单重复数据；要寻找规律、趋势或关系。例如，“随着温度升高至40°C，淀粉分解速率增加，超过40°C后速率下降。”
Explain your results using scientific ideas. If the enzyme activity dropped above 40°C, you could state that the high temperature denatures the enzyme, changing the shape of its active site so it no longer fits the substrate.
用科学概念解释结果。如果超过40°C酶活性下降，你可以指出高温使酶变性，改变了活性部位的形状，使其不再与底物匹配。
If the data does not support your hypothesis, say so honestly and suggest possible reasons. A conclusion that does not match the prediction can still lead to valuable learning.
如果数据不支持你的假设，要如实说明，并提出可能的原因。一个与预测不符的结论仍然能带来宝贵的学习机会。
10. Evaluating Experiments | 实验评估
An evaluation is a critical look at your method. Identify any anomalies in the data and consider whether repeat readings were close or scattered. Comment on the reliability and precision of your results.
评估是对实验方法的批判性审视。识别数据中的任何异常值，并考虑重复读数是否接近或分散。评论结果的可靠性和精确度。
Suggest improvements to make the method more accurate or to control variables better. For example, use a digital thermometer instead of a liquid-in-glass one to get exact temperature readings, or measure the pondweed piece to a fixed length each time.
提出改进方法，使实验更精确，或更好地控制变量。例如，使用数字温度计取代液体温度计以获得准确温度读数，或每次将水草切成固定长度。
Reflect on how you could extend the investigation. Ask a new question such as 'What would happen if we used different colours of light?' or 'How does pH affect the reaction?'. This shows curiosity and deeper thinking.
思考如何扩展探究。提出新问题，如“如果使用不同颜色的光会怎样？”或“pH值如何影响该反应？”。这体现了好奇心和更深层的思考。
Published by TutorHao | Biology Revision Series | aleveler.com
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