OCR · A-Level · Biology
Course version: H420 · Version from Sept 2025
(a) how to use a wide range of practical apparatus and techniques correctly
Full specification wording
Implementing: (a) how to use a wide range of practical apparatus and techniques correctly
Correct use of apparatus means selecting suitable equipment and operating it so measurements are accurate, safe and repeatable.
Checked against the OCR H420 specification (opens in a new tab) on .
- Point 1 of 3
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Correct use of apparatus means selecting suitable equipment and operating it so measurements are accurate, safe and repeatable. Know the purpose of common items: a volumetric pipette delivers a fixed accurate volume, a measuring cylinder gives a quicker but less precise volume, a burette allows controlled variable delivery, and a colorimeter measures absorbance to follow a colour change. Match technique to task: read a meniscus at eye level, zero a balance before weighing, calibrate a colorimeter with a blank, and use a water bath to hold temperature constant. Recognise when a technique is unsuitable, such as using a measuring cylinder where a volumetric pipette is needed for accuracy. Selecting and using the right apparatus correctly underpins valid, reliable practical work.
What earns the marks
- Selects apparatus whose precision and function match the measurement required by the task.
- Describes correct operation, such as reading a meniscus at eye level or zeroing a balance before use.
- Recognises the need to calibrate or set up equipment, for example using a blank with a colorimeter.
- Identifies an unsuitable choice of apparatus and explains why a more appropriate item should be used.
- Applies correct technique to control a variable, such as maintaining temperature with a water bath.
Common mistakes and how to put them right
Choosing apparatus by convenience rather than precision.
Put it right: Match the precision of the instrument to the accuracy the measurement needs.
Ignoring calibration or zeroing.
Put it right: Set up and calibrate equipment before taking readings.
Reading scales at an angle or from the wrong part of the meniscus.
Put it right: Read at eye level at the correct reference point.
Assuming any glassware measures accurately.
Put it right: Distinguish fixed-volume accurate vessels from approximate measuring vessels.
Exam tips
- Read the question's required precision before choosing apparatus, then justify the choice.
- Link each technique to the variable it controls or the quantity it measures.
- When spotting an error, name the correct apparatus or procedure rather than only saying it is wrong.
Try the lesson
The start of the Implementing: (a) how to use a wide range of practical apparatus and techniques correctly lesson, made from checked teaching notes for this specification point.
Have a go first
A student wants to observe onion cells under a light microscope. Which technique correctly prepares a temporary slide?
Listen
Correct use of apparatus means selecting suitable equipment and operating it so measurements are accurate, safe and repeatable. Know the purpose of common items: a volumetric pipette delivers a fixed accurate volume, a measuring cylinder gives a quicker but less precise volume, a burette allows controlled variable delivery, and a colorimeter measures absorbance to follow a colour change. Match technique to task: read a meniscus at eye level, zero a balance before weighing, calibrate a colorimeter with a blank, and use a water bath to hold temperature constant. Recognise when a technique is unsuitable, such as using a measuring cylinder where a volumetric pipette is needed for accuracy. Selecting and using the right apparatus correctly underpins valid, reliable practical work. A strong answer earns marks for these points. Selects apparatus whose precision and function match the measurement required by the task. Describes correct operation, such as reading a meniscus at eye level or zeroing a balance before use. Recognises the need to calibrate or set up equipment, for example using a blank with a colorimeter. Identifies an unsuitable choice of apparatus and explains why a more appropriate item should be used. A common slip: Choosing apparatus by convenience rather than precision. Instead, match the precision of the instrument to the accuracy the measurement needs. Exam tip: Read the question's required precision before choosing apparatus, then justify the choice.
Key words
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Apparatus selection matched to purpose
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Accurate measurement technique
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Calibration and correct set-up
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Controlling variables with appropriate equipment
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See every definition
- Apparatus selection matched to purpose
- Choosing equipment whose precision and function match the measurement required by the task, rather than choosing by convenience.
- Accurate measurement technique
- Operating equipment correctly, such as reading a meniscus at eye level or zeroing a balance before weighing.
- Calibration and correct set-up
- Setting up and calibrating equipment before taking readings, for example using a blank with a colorimeter.
- Controlling variables with appropriate equipment
- Applying correct technique to control a variable, such as maintaining temperature with a water bath.
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