A-Level Biology: Inheritance, Populations and Evolution
Genetics and evolution at A-level combine cross-diagram fluency with population-level mathematics, and the exam rewards students who can move between the two. This set — quiz, flashcards, printable written questions and a spoken exam — spans that whole range.
The inheritance questions cover the standard cross repertoire with concrete, fully stated scenarios: the 3:1 monohybrid ratio from a heterozygous self-cross, the 9:3:3:1 dihybrid ratio with independent assortment, codominance through the ABO system — tested on which genotype produces the AB phenotype — and the pre-zygotic versus post-zygotic sorting of isolation mechanisms.
The statistics layer is exam-realistic: a chi-squared interpretation question — calculated value exceeding the critical value at the 0.05 level means the difference is significant and the null hypothesis falls, the phrasing students routinely invert — and a full Hardy-Weinberg calculation from raw numbers (20 homozygous recessives in 500 individuals, q² = 0.04, q = 0.2), with the equilibrium's assumptions tested separately as a multi-select.
The evolution questions complete the set: selection types with disruptive selection tested by its both-extremes signature and speciation link, the founder effect identified from concrete scenarios, genetic drift, and the allopatric-sympatric distinction by the presence or absence of geographic separation.
Every cross states its alleles and every calculation gives its numbers in the question body. The explanations show working, not just answers — matching how this section's marks are actually awarded — and the set follows naturally from the Genes and Protein Synthesis quiz in this collection.
- Predict mono- and dihybrid ratios and handle codominance and multiple alleles
- Interpret chi-squared results against critical values correctly
- Perform Hardy-Weinberg allele-frequency calculations from raw counts
- Classify selection types and isolation mechanisms
- Distinguish allopatric from sympatric speciation and recognise drift and founder effects
Topic scope follows the genetics, populations and evolution content of the DfE A level biology subject content as delivered in current exam-board specifications: inheritance patterns, chi-squared, Hardy-Weinberg, selection and speciation.
Sample question
Which of the following statements correctly describe the characteristics of the Hardy-Weinberg principle? Select all that apply.
- The population must be large to minimise the effects of genetic drift.
- Natural selection must be actively occurring to drive allele frequency changes.
- There must be no significant mutation rate within the population.
- Mating within the population is non-random.
See the answer
The population must be large to minimise the effects of genetic drift., There must be no significant mutation rate within the population.
The Hardy-Weinberg principle assumes a large population, no mutation, no natural selection, no gene flow, and random mating to maintain constant allele frequencies.
Try this quiz →Try this exam →Practice these flashcards →Try this written work →
- A-Level Biology: Cell Structure and Division
- A-Level Biology: Genes and Protein Synthesis
- A-Level Biology: Transport in Plants
- A-Level Biology: Synoptic Essays
- A-Level Biology: Stimuli, Receptors and Heart-Rate Control
- A-Level Biology: Statistics and Data Analysis
- History
- Psychology
- Chemistry
- Physics
- Economics
- Mathematics
- English Literature
- Sociology
- Business
- Computer Science
- Geography
- Politics
A levels are awarded by AQA, Pearson Edexcel, OCR, WJEC/Eduqas and CCEA, and regulated by Ofqual, Qualifications Wales and CCEA Regulation, the regulators for England, Wales and Northern Ireland. Zestly is not affiliated with or endorsed by Ofqual, UCAS or any awarding body. These materials are our own and reproduce no past-paper content.