BRAINCAKE

Genes, inheritance and selection

OCR GCSE BiologyTopic 5 of 619 lessons

Revision notes for Genes, inheritance and selection in OCR Biology A (J247). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.

  1. Key terms in inheritanceA gamete is a sex cell, such as a sperm or an egg.
  2. The genomeThe genome of an organism is its entire genetic material.
  3. Genome, environment and phenotypeAn organism's phenotype is shaped by its genome and by how the genome interacts with the environment.
  4. Mutations and variantsDifferent alleles of a gene, called variants, all arise from mutations.
  5. How variants influence phenotypeA gene in coding DNA has a sequence of bases that decides the order of amino acids in a protein.
  6. Asexual and sexual reproductionIn asexual reproduction there is only one parent and no gametes are involved.
  7. Haploid and diploid cellsHuman body cells contain chromosomes in pairs.
  8. Meiosis, gametes and variationMeiosis is the type of cell division that makes gametes.
  9. Single gene inheritanceSome features are controlled by a single gene.
  10. Punnett squares and single gene crossesA Punnett square is a grid that shows every possible combination of alleles when gametes from two parents fuse.
  11. Sex determination in humansHuman body cells have 23 pairs of chromosomes.
  12. Features controlled by many genesSingle gene inheritance, with one gene and a dominant and a recessive allele, controls only a few features.
  13. Mendel and the development of our understanding of geneticsGregor Mendel was a monk who worked in a monastery garden in the 1850s and 1860s.
  14. Genetic variation in a populationLook at any group of the same species, such as the dogs in a park or the daisies on a lawn, and no two individuals are exactly the same.
  15. Classification and developments in biologyScientists sort living things into groups to make them easier to study.
  16. Natural selectionEvolution by natural selection explains how species become suited to their environment.
  17. Evolution and new speciesEvolution is a change in the inherited characteristics of a population over time, through a process of natural selection.
  18. Evidence for evolutionOne piece of evidence for evolution is the fossil record.
  19. Darwin, Wallace and modern biologyCharles Darwin and Alfred Russel Wallace both developed the theory of evolution by natural selection.

All OCR GCSE Biology topics