3.1Unit 3: Practical Skills in Biology I
Practical Skills in Biology I — IAL Edexcel Linear Revision Notes & Topical Questions
5 min read 7 parts Lesson 1 of 27 2 quizzes
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
Lesson summary
3.1 Unit 3 IAL Linear Biology notes: million students studying our academic and vocational qualifications worldwide, we offer internationally recognised qualifications to schools, colleges and employers globally.
- 3.1 Unit 3 IAL Linear Biology: what to do next
- 3.1 Unit 3 IAL Linear Biology: revision checklist
- Hypothesis
- Independent variable
- Control variable
- Repeatability
Part 1 of 6Key ideas
Key ideas
Use appropriate significant figures.
Anomalies should be identified and explained.
Risk assessment is required for every practical.
Part 2 of 6Syllabus points
- million students studying our academic and vocational qualifications worldwide, we offer internationally recognised qualifications to schools, colleges and employers globally. - modular assessment, offered at different times of the year to suit your delivery model - practical skills assessed through a dedicated examination unit, both at AS (Unit 3) and at A Level (Unit 6) - comparable content with the UK GCE AS and A Level - giving confidence to students, teachers and universities on comparability of the specifications - a range of question types in exams - testing breadth of knowledge, as well as allowing depth of understanding to be examined. - develop and use a range of mathematical skills that support their knowledge and understanding of biology - gain experience in a variety of practical techniques and procedures, which will be assessed separately in units 3 and 6 - widen their learning through a number of key transferable skills, which may be cognitive, intrapersonal or interpersonal (see Appendix 3
- Transferable skills). - Our Getting Started Guide gives you an overview of the Pearson Edexcel International Advanced Subsidiary and Advanced Levels in Biology to help you understand the changes to content and assessmentand what these changes mean for you and your students.
- - We will provide you with an editable course planner and the scheme of work to save you time in planning and help you to put together teaching strategies for delivering the specification content.
- - Our mapping documents highlight key differences between the new and legacy qualifications to help you understand the changes made to the new specifications. - Course planners and schemes of work - to help you to put together teaching strategies for delivering the specification content.
- Support and Assessment Materials
- Practical Skills Guides and Mathematical Skills Guides to support developing key experimental skills.
- Getting Ready to Teach and other training events available locally and online.
- Printed textbooks and digital teaching resources promoting flexible learning.
- Specimen papers to support formative assessments and mock exams, alongside examiner commentaries.
- Core modules
- Molecules, Transport and Health;
- Membranes, Proteins, DNA and Gene Expression;
- Cell Structure, Reproduction and Development;
- Plant Structure and Function, Biodiversity and Conservation.
- Molecules, Transport and Health;
Part 3 of 6Process & sequence
1
State a hypothesis.
2
Identify variables and controls.
3
Plan method with repeats.
4
Record in a table with units.
5
Plot graph and use a statistical test.
6
Evaluate errors and reliability.
- QuestionHypothesisMethodResultsAnalysisConclusion
Part 4 of 6Summary
Summary
The variable you change is the independent variable.
Aseptic technique prevents contamination.
Part 5 of 6Keep going
3.1 Unit 3 IAL Linear Biology: what to do next
These 3.1 Unit 3 IAL Linear Biology notes covered the key ideas, worked examples and exam technique for this topic. Check your 3.1 Unit 3 IAL Linear Biology understanding with the practice questions below, then reread any 3.1 Unit 3 IAL Linear Biology point you were unsure about before moving on.
3.1 Unit 3 IAL Linear Biology: revision checklist
- Revise the main 3.1 Unit 3 IAL Linear Biology definitions until you can write them from memory.
- Practice: 3.1 Unit 3 IAL Linear Biology practice questionsPrevious lesson: 2.6 SNAB Resources from Plants — Notes — IAL Biology NotesNext lesson: 3.2 Using a light microscope and cell ultrastructure — NotesCourse: IAL Edexcel Linear — all unitsOfficial syllabus: Pearson Edexcel International A Levels
Part 6 of 6Compare: Compare
| Skill | Purpose | Example practical | Equipment | Error to avoid | Data |
|---|---|---|---|---|---|
| Microscopy | Observe cells | Onion epidermis, mitosis | Light microscope, graticule | Not calibrating | Magnification, drawings |
| Enzyme rates | Effect of factors | Temperature on amylase | Water bath, colorimeter | Temperature drift | Rate vs temperature |
| Osmosis | Find water potential | Potato cylinders | Balance, sucrose solutions | Not blotting dry | % mass change |
| Chromatography | Separate pigments | Leaf pigments | TLC plate, solvent | Spot too large | Rf values |
| Sampling | Estimate populations | Quadrats | Quadrat, random numbers | Biased placement | Mean density |
| Aseptic technique | Grow microbes safely | Antibiotic discs | Agar plates, flame | Contamination | Zone of inhibition |
Key terms
Command terms
Command terms
Give / State / Name
Recall a fact; one idea per mark.
Define
Give the exact meaning using the specification keywords.
Describe
Give an account of what happens / the pattern in data, quoting values; no reasons needed.
Explain
Give reasons with linked statements (cause → effect). Each linked step is usually a separate marking point.
Suggest
Use knowledge in a new context; more than one answer may be accepted.
Compare
Similarities and differences; each point must refer to both items.
Calculate
Show working; include units; check significant figures. Method marks are given even if the final answer is wrong.
Discuss
Explore the issue from different angles and link the points.
Evaluate / Assess
Weigh strengths and weaknesses and reach a supported judgement.
Deduce
Draw a conclusion from the information given.
Justify
Support a statement/choice with evidence.
Exam technique
Keywords the mark scheme looks for in this lesson
Keywords the mark scheme looks for in this lesson
Hypothesis · Independent variable · Dependent variable · Control variable · Repeatability · Reproducibility · Serial dilution · Statistical test
Learn each definition in the Key words tab exactly; a missing keyword in a definition usually loses the mark.
How to get full marks (examiner guidance)
How to get full marks (examiner guidance)
Use specification keywords exactly (e.g. eukaryotic/prokaryotic, enzyme–substrate complex, active site, complementary).
Link ideas
Link ideas for “explain” each marking point is usually a cause → consequence step; unlinked facts often score nothing.
Use the information in the question
“discuss/evaluate” answers must use the data provided and match the number of marks.
Convert units carefully (mg → g, cm³ → dm³) and show working for calculations.
Avoid vague words
“it”, “stuff”, “things”, “goes up”, “energy is made”. Name the substance and the process.
Do not extrapolate a graph line beyond the data or to zero unless asked.
Six-mark extended responses are marked on content AND a logical, linked line of reasoning.
Marked practiceQuizzes for this lesson
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