Key term
Eduqas A-Level Biology A400QS
Biological Molecules
Cell Structure and Organisation
Cell Membranes and Transport
Enzymes
Nucleic Acids and Their Functions
Importance of ATP
Photosynthesis
Respiration
Microbiology
Population Size and Ecosystems
Topic overviewPopulation growth and its measurementThe population growth curve and carrying capacityDensity dependent and density independent factorsSampling abundance and distributionEcosystems, habitats and communitiesEnergy transfer and pyramids of biomassSuccessionDecomposition and the carbon cycleThe nitrogen cycle and human interventionEutrophication and the effects of drainage
Human Impact on the Environment
Classification and Biodiversity
Topic overviewThe need for classification and the taxonomic hierarchyThe three domain and five kingdom systemsCharacteristic features of the five kingdomsAssessing relatedness by physical features and biochemistryThe species concept and the binomial systemBiodiversity, adaptation and natural selectionMeasuring biodiversity in a habitatGenetic and molecular measures of biodiversity
Mitosis and Meiosis
Sexual Reproduction in Humans
Sexual Reproduction in Plants
Inheritance
Variation and Evolution
Application of Reproduction and Genetics
Topic overviewThe Human Genome Project, other sequenced genomes and genomics in healthcareScreening embryos, stem cells and the ethical issuesGenetic fingerprinting, PCR and electrophoresis in forensic workRecombinant DNA and the production of human insulinGenetically modified crops and gene therapy
Adaptations for Gas Exchange
Topic overviewSurface area to volume ratio and gas exchange in small organismsSpecialised respiratory surfaces and the need for ventilationGills and counter current flow in bony fishThe human breathing system and its histologyVentilation and gas exchange in humansThe insect tracheal systemThe angiosperm leaf, stomata and gas exchange
Adaptations for Transport
Topic overviewVascular systems compared across animal groupsThe mammalian heart and blood vesselsThe cardiac cycle and its controlBlood, haemoglobin and dissociation curvesThe Bohr effect, chloride shift and tissue fluidThe root and the uptake of waterThe endodermis and the entry to the xylemXylem, transpiration and cohesion-tensionThe potometer and xerophytes and hydrophytesPhloem and translocation
Adaptations for Nutrition
Homeostasis and the Kidney
The Nervous System
Immunology and Disease: Disease and Its TransmissionImmunology
Immunology and Disease: AntibioticsImmunology
Immunology and Disease: The Immune ResponseImmunology
Human Musculoskeletal Anatomy: Skeletal TissuesMusculoskeletal
Topic overviewCartilage and its three typesThe composition and functions of compact boneBone remodelling and the Haversian systemRickets, osteomalacia, osteoporosis and brittle bone diseaseThe structure of skeletal muscleThe sliding filament theoryFast and slow twitch fibres, and energy for contraction
Human Musculoskeletal Anatomy: Structure and Function of the SkeletonMusculoskeletal
Human Musculoskeletal Anatomy: JointsMusculoskeletal
Neurobiology and Behaviour: The BrainNeurobiology
Neurobiology and Behaviour: NeuroscienceNeurobiology
Inheritance
- 5 subtopics
- 15 things to know
- Component 2
What Inheritance covers
Inheritance is examined in Component 2, Continuity of Life. It covers alleles, monohybrid inheritance and codominance, dihybrid inheritance and linkage, the chi squared test and testing genetic ratios, sex linkage, haemophilia and Duchenne muscular dystrophy and mutation, mutagens and epigenetics.
The 5 subtopics
Each one has its own page.
- Alleles, monohybrid inheritance and codominanceTerm allele, term locus and dominant allele.Open →
- Dihybrid inheritance and linkageDihybrid inheritance, mendel's law of independent assortment and why linked genes do not assort independently.Open →
- The chi squared test and testing genetic ratiosEquation used in the chi squared test, data must be used in a chi squared test and null hypothesis used in a genetic chi squared test.Open →
- Sex linkage, haemophilia and Duchenne muscular dystrophySex-linked gene, biological cause of haemophilia and effect of Duchenne muscular dystrophy.Open →
- Mutation, mutagens and epigeneticsGene mutation, mutation responsible for sickle cell anaemia and chromosome mutation.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
What are the expected children of a carrier mother, and why are males affected far more often?
Key term
Describe an experiment to illustrate gene segregation and test its outcome statistically.
Key term
Define the term allele.
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What is meant by dihybrid inheritance?
Key term
Define gene mutation.
Key term
Define the term locus.
Process
Which stage of meiosis is responsible for independent assortment?
Key term
What kind of data must be used in a chi squared test?
Key term
Why is the sickle cell allele common in some parts of Africa?
Key term
Distinguish genotype from phenotype.
Key term
State the phenotype ratio expected when two organisms heterozygous for two unlinked genes are crossed.
Key term
State the null hypothesis used in a genetic chi squared test.
Key term
Name the sex chromosomes carried by a human male and by a human female.
Key term
Define chromosome mutation.
Take Inheritance further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Homozygous vs Heterozygous
Homozygous: the two copies at a locus are the same. Heterozygous: it means they differ.
Questions from this topic
Each one with the model answer underneath.
- 1
Define the term allele.
Model answer
An allele is one of the different forms of a gene, occupying the same locus on a chromosome.
- 2
Define the term locus.
Model answer
A locus is the fixed position on a chromosome at which a particular gene is always found.
- 3
Distinguish genotype from phenotype.
Model answer
The genotype is the combination of alleles an organism carries, whereas the phenotype is the observable characteristic that results from those alleles and from the environment.
- 4
What does it mean to describe an organism as homozygous for a gene?
Model answer
It carries two identical alleles of that gene at the matching loci of a homologous pair.
- 5
What is a dominant allele?
Model answer
A dominant allele is one that is expressed in the phenotype even when only a single copy of it is present.
- 6
State Mendel's law of segregation.
Model answer
The two alleles of a gene separate from one another during meiosis, so each gamete receives only one of them.
What is inside Levo
Six ways to work the same material.
Inheritance revision questions
- What does Inheritance cover in Eduqas A-Level Biology?
- 5 subtopics: alleles, monohybrid inheritance and codominance, dihybrid inheritance and linkage, the chi squared test and testing genetic ratios, sex linkage, haemophilia and duchenne muscular dystrophy and mutation, mutagens and epigenetics. Each one has its own page with questions and model answers.
- How is Inheritance organised?
- By the Eduqas A400QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Inheritance, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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