Numbers
AQA GCSE Biology 8461
Bioenergetics
Cell Biology
Topic overviewEukaryotes and prokaryotesAnimal and plant cellsCell specialisation and differentiationMicroscopyGrowing bacteria and aseptic techniqueCalculating bacterial growth, and testing antiseptics and antibioticsChromosomes, mitosis and the cell cycleStem cells in embryos, adults and meristemsTherapeutic cloning, its risks, and cloning plantsDiffusion and the factors affecting its rateSurface area to volume ratio and exchange surfacesOsmosisActive transport
Ecology
Topic overviewLevels of organisation in an ecosystem, and what organisms needCompetition, interdependence and stable communitiesAbiotic factorsBiotic factorsAdaptationsProducers, food chains and sampling with quadrats and transectsPredators, prey and measuring population sizeHow materials are cycledDecompositionWaste management and biodiversityLand use, deforestation and global warmingMaintaining biodiversityTrophic levels and pyramids of biomassTransfer of biomassFactors affecting food securityFarming techniques and sustainable fisheriesRole of biotechnology
Homeostasis and Response
Topic overviewHomeostasisThe nervous system and the reflex arcThe structure of the eye and accommodationMyopia, hyperopia and how they are correctedThe brain and the control of body temperatureHuman endocrine systemInsulin, glucagon and diabetesWater and ion loss, and the production of ureaThe kidneys, ADH and treating kidney failureHormones in human reproductionContraceptionPlant hormones and their uses
Infection and Response
Inheritance, Variation and Evolution
Topic overviewSexual and asexual reproductionMeiosisAdvantages and disadvantages of sexual and asexual reproductionDNA and the genomeDNA as a polymer of four nucleotidesGenetic terms, dominant and recessive allelesPunnett squares, probability and genetic crossesInherited disorders and sex determinationVariationEvolutionSelective breedingWhat genetic engineering is, and what it is used forGM crops, their risks, and the steps of the processCloningDarwin, Lamarck and the acceptance of evolutionSpeciationThe understanding of geneticsEvidence for evolution, and extinctionFossilsResistant bacteriaClassification of living organisms
Organisation
Topic overviewLevels of organisation, and how enzymes workAmylase, proteases and lipasesBile, food tests and the effect of pH on amylaseThe heart, the lungs and double circulationThe pacemaker, the blood vessels and the bloodCoronary heart disease: a non-communicable diseaseHealth issuesRisk factors and causal mechanisms in diseaseSampling, correlation and interpreting risk dataCancerPlant tissues, and transpiration and its rateRoot hair cells, xylem, phloem and stomata
Inheritance, Variation and Evolution
- 21 subtopics
- 45 things to know
- Paper 2
What Inheritance, Variation and Evolution covers
Inheritance, Variation and Evolution is examined in Biology Paper 2. It covers sexual and asexual reproduction, meiosis and the advantages of each type of reproduction; DNA, the genome and its four nucleotides; genetic terms, Punnett squares and genetic crosses; inherited disorders and sex determination; variation and evolution; selective breeding, genetic engineering, GM crops and cloning; Darwin, Lamarck, Wallace, speciation and the understanding of genetics; evidence for evolution, extinction, fossils and resistant bacteria; and the classification of living organisms.
Where it is assessed
Paper 2
Biology Paper 2: 1 hour 45 minutes, 100 marks, 50% of the GCSE.
Check the AQA specification ↗The 21 subtopics
Each one has its own page.
- Sexual and asexual reproductionMitosis and meiosis, gametes in animals and flowering plants and their fusion at fertilisation, why sexual reproduction produces variation, and asexual reproduction from one parent by mitosis producing clones.Open →
- MeiosisHow meiosis halves the chromosome number and fertilisation restores it, where it happens, copying then two divisions giving four different gametes, and mitosis in the growing embryo.Open →
- Advantages and disadvantages of sexual and asexual reproductionVariation and natural selection as advantages of sexual reproduction, selective breeding, the speed and efficiency of asexual reproduction in stable conditions, organisms that use both such as malarial parasites, fungi and strawberries, and choosing a type of reproduction for roses, greenfly and fish farms.Open →
- DNA and the genomeNucleus, chromosome and gene by size, the double helix and DNA as a polymer, what a gene codes for, and what studying the human genome offers medicine and migration history.Open →
- DNA as a polymer of four nucleotidesThe sugar, phosphate and base of a nucleotide, the four bases A, C, G and T, three bases coding for each amino acid and how many amino acids a sequence codes for, and the alternating sugar and phosphate structure of each strand.Open →
- Genetic terms, dominant and recessive allelesGametes, chromosomes, alleles, genotype and phenotype, characteristics controlled by a single gene, dominant and recessive alleles and when each is expressed, and homozygous and heterozygous organisms.Open →
- Punnett squares, probability and genetic crossesCharacteristics controlled by several genes, why a cross predicts only probabilities, ratios and percentages from 3:1 and 1:1 crosses, worked crosses in mice and cats, and identifying a recessive allele from a family tree.Open →
- Inherited disorders and sex determinationPolydactyly and cystic fibrosis, their dominant and recessive alleles, the case for and against embryo screening, the 23 chromosome pairs, XX and XY, and the chance of a boy.Open →
- VariationVariation caused by genes, the environment or both, why siblings and cloned plants differ, extensive genetic variation arising from mutations, how few variants affect the phenotype, and how a new phenotype suited to a changed environment can spread quickly.Open →
- EvolutionThe definition of evolution, natural selection and new species, why it acts on populations, simple life forms over three billion years ago, mutations as the source of variation, and the interbreeding test.Open →
- Selective breedingSelective breeding or artificial selection and its history, choosing and breeding parents over many generations, characteristics chosen in crops, farm animals, dogs and flowers, inbreeding and its problems, and the effects on variation and food production.Open →
- What genetic engineering is, and what it is used forThe definition of genetic engineering, where the new gene comes from, engineered crops and insulin from bacteria, cutting out and transferring a gene, and the benefits, objections and risks.Open →
- GM crops, their risks, and the steps of the processWhat genetically modified crops are and the insect and herbicide resistance and higher yields they give, concerns about wild flowers, insects, birds and human health, and hopes of using genetic modification to overcome inherited disorders.Open →
- CloningTissue culture for conservation and nurseries, taking cuttings, splitting embryos for embryo transplants, and adult cell cloning, from replacing an egg cell nucleus and an electric shock to implanting the embryo, and why the clone matches the nucleus donor.Open →
- Darwin, Lamarck and the acceptance of evolutionDarwin's observations, the theory of natural selection and On the Origin of Species, why acceptance was slow, the later discovery of genes, and Lamarck's idea of inherited acquired changes.Open →
- SpeciationAlfred Russel Wallace, his joint writings with Darwin in 1858, his worldwide evidence and work on warning colouration, the impact of Darwin and Wallace's ideas, and speciation as isolated populations become genetically different until they can no longer interbreed.Open →
- The understanding of geneticsMendel's breeding experiments on plants and why their importance was missed, the observation of chromosome behaviour, the link between Mendel's units and chromosomes, units renamed genes, the structure of DNA and gene function, and gene theory as the work of many scientists.Open →
- Evidence for evolution, and extinctionThe fossil record and antibiotic resistance as evidence, the discovery of genes, what extinction means, and how environmental change, disease, new predators, competition and low variation cause it.Open →
- FossilsWhat fossils are and where they form, preservation without decay, replacement by minerals and preserved traces, why early life left few, and reading evolutionary trees and common ancestors.Open →
- Resistant bacteriaWhy bacteria evolve rapidly, how mutation and antibiotic use produce and spread resistant strains such as MRSA, slowing resistance by limiting prescriptions, completing courses and restricting farm use, and the cost and slowness of developing new antibiotics.Open →
- Classification of living organismsThe Linnaean groups from kingdom to species, binomial names and what shared groups show about relatedness, how microscopes and biochemistry changed classification, Carl Woese's three domains of archaea, bacteria and eukaryota, and placing organisms on evolutionary trees.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
List the Linnaean groups from largest to smallest, explain how the binomial system names an organism, and say whether a genus or an order is the more specific group.
Key term
Which type of cell division produces cells that are genetically identical to one another?
Process
How is the full number of chromosomes restored after gametes have been formed?
Key term
How does the variation produced by sexual reproduction help a species when its environment changes?
Key term
Put these in order of size, largest first: gene, chromosome, nucleus.
Key term
What is a gamete?
Key term
Are most characteristics controlled by one gene or by many?
Key term
Is polydactyly caused by a dominant or a recessive allele?
Key term
What is meant by variation?
Key term
What is evolution?
Key term
What is selective breeding?
Key term
Give two characteristics that crop plants have been genetically engineered to have.
Key term
What is a genetically modified crop?
Key term
Give one commercial use of tissue culture.
Key term
Which two developing areas of scientific knowledge was Darwin's theory linked to?
Key term
Who independently proposed the theory of evolution by natural selection at the same time as Darwin?
Key term
What did Mendel conclude determined the inheritance of each characteristic?
Key term
Name two kinds of evidence for evolution.
Key term
What are fossils?
Key term
A population of bacteria doubles every 20 minutes. Explain why this makes resistance a serious problem.
Key term
Why are the cells produced by meiosis described as non-identical?
Key term
What is the first thing that happens in a cell that is about to divide to form gametes?
Key term
State two ways in which asexual reproduction saves an organism time and energy.
Key term
What shape are the two strands of a DNA molecule twisted into?
Key term
What are the three parts of a single DNA nucleotide?
Key term
What is a chromosome?
Key term
Why can a genetic cross only predict the likely proportions of the offspring?
Key term
Which part of the cell is affected in cystic fibrosis?
Key term
Give the three possible causes of variation between individuals.
Key term
What can evolution eventually result in?
Key term
Once the first generation of offspring has been produced, what is done next?
Key term
What has to be put into a bacterial cell so that it will produce a human substance?
Key term
Give two characteristics that genetically modified crops have been given.
Key term
How does a gardener produce new plants from cuttings?
Key term
What did Darwin observe about a characteristic within a single species?
Key term
How did Wallace gather his evidence for evolutionary theory?
Key term
Put these three advances in the order they happened: the structure of DNA was determined; Mendel's breeding experiments; the behaviour of chromosomes was observed.
Key term
Give two factors that can contribute to the extinction of a species.
Key term
How can a fossil form when no decay has taken place?
Key term
Why does the population of a resistant strain rise?
Key term
List the groups used by Linnaeus in order, from the largest to the smallest.
Key term
Name the male gamete and the female gamete in animals.
Key term
How many sets of chromosomes does each gamete contain?
Key term
Which is faster, sexual or asexual reproduction?
Take Inheritance, Variation and Evolution further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Dominant allele vs Recessive allele
Dominant allele: a version of a gene that shows its effect with only one copy present. Recessive allele: a version of a gene that shows its effect only when two copies are present.
Genotype vs Phenotype
Genotype: the alleles an organism carries for a characteristic. Phenotype: the characteristics that an organism actually shows.
Homozygous vs Heterozygous
Homozygous: carrying two identical alleles for a characteristic. Heterozygous: carrying two different alleles for a characteristic.
Questions from this topic
Each one with the model answer underneath.
- 1
Which type of cell division produces cells that are genetically identical to one another?
Model answer
Mitosis produces genetically identical cells.
- 2
Why are the cells produced by meiosis described as non-identical?
Model answer
Meiosis produces cells that all differ from each other genetically, unlike mitosis, which produces identical copies.
- 3
What happens to the male and female gametes during sexual reproduction?
Model answer
They join together, or fuse, at fertilisation.
- 4
Name the male gamete and the female gamete in animals.
Model answer
The sperm cell is the male gamete and the egg cell is the female gamete.
- 5
Name the male gamete and the female gamete in flowering plants.
Model answer
Pollen is the male gamete and the egg cell is the female gamete.
- 6
Why does sexual reproduction produce offspring that vary?
Model answer
Genetic information from two parents is mixed, so the offspring are not identical to either parent or to each other.
What is inside Levo
Six ways to work the same material.
Inheritance, Variation and Evolution revision questions
- What does Inheritance, Variation and Evolution cover in AQA GCSE Biology?
- 21 subtopics: sexual and asexual reproduction, meiosis, advantages and disadvantages of sexual and asexual reproduction, dna and the genome, dna as a polymer of four nucleotides, genetic terms, dominant and recessive alleles, punnett squares, probability and genetic crosses, inherited disorders and sex determination, variation, evolution, selective breeding, what genetic engineering is, and what it is used for, gm crops, their risks, and the steps of the process, cloning, darwin, lamarck and the acceptance of evolution, speciation, the understanding of genetics, evidence for evolution, and extinction, fossils, resistant bacteria and classification of living organisms. Each one has its own page with questions and model answers.
- How is Inheritance, Variation and Evolution organised?
- By the AQA 8461 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Inheritance, Variation and Evolution, on a schedule.
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