4.2 Inheritance: How do organisms grow and reproduce?
Relate DNA and protein coding to cell division, stem cells and patterns of inheritance.
How to study WJEC GCSE The Sciences
Move from a scientific model to a prediction or method, collect or interpret evidence, show quantitative working and finish with a conclusion whose limits match the data.
Core concepts
Concept 1
Describe DNA, chromosomes, genes and complementary base pairing.
Exam cue: Identify the unit, entered tier, supplied reference material, command word and relevant scientific enquiry skill.
Concept 2
Compare cell division and evaluate stem-cell uses and issues.
Exam cue: Define allele symbols, show gametes and offspring genotypes, then distinguish probability from certainty.
Concept 3
Use genetic diagrams to predict inheritance probabilities.
Exam cue: Use scientific terminology, show quantitative working with units, and connect conclusions to data and the stated model.
Concept 4
Official subtopics: 4.2.1 DNA structure and function; 4.2.2 Stem cells; 4.2.3 Inheritance.
Concept 5
Scientific enquiry and mathematical skills apply in this topic; bold amplification is Higher Tier only.
Risk pitfalls and guardrails
Confusing a gene, allele, chromosome and DNA molecule or treating predicted ratios as guaranteed outcomes.
Guardrail: Do not import outgoing 3430QD content, another science route, a fixed required-practical list or unsupported tier and connection assumptions.
Recalling a fact without applying it to the observation, data, practical method or unfamiliar context.
Guardrail: Use the live secure pack: Task A may use groups of up to three; Task B is individual and highly controlled. Two enquiries are selected by the centre from three.
Importing content, required practicals, tier rules or paper structure from the outgoing WJEC or another awarding-body route.
Guardrail: Bold amplification is Higher-only. Units 1-6 may mix tiers, but Unit 7 is untiered.
Memory anchors
Gene
A section of DNA that codes for a product and influences a characteristic.
Allele
An alternative version of a gene.
Genotype
The allele combination an organism carries.
Phenotype
Observable characteristics produced by genotype and environment.
Stem cell
An unspecialised cell able to divide and differentiate.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
Which sequence correctly describes the main events of the cell cycle before two daughter cells form? Track DNA, cell division and allele combinations without confusing genes and chromosomes. Use only the measurements stated in the stem.
Why must DNA be replicated before mitosis? Track DNA, cell division and allele combinations without confusing genes and chromosomes. Use the overall trend rather than an isolated value.
Answer all questions to submit.
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Move forward only after this module is stable.
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