3.2 - breeding

• What qualities do plant and animal breeders seek in crops and animals?

  • Higher food yield
  • higher nutritional values
  • pest and disease resistance
  • ability to thrive in particular environmental conditions
• Why are plant field trials carried out?

  To compare the performance of different cultivars or treatments and to evaluate GM crops
• What does plant and animal breeding involve?

  The manipulation of hereditary
• What factors should be taken into consideration when designing a field trial treatment?

  • Valid comparison
  • number of replicates to take account of variability
  • randomisation of treatments to eliminate bias when measuring treatment effects
• What is inbreeding ?

  Selected related plants/animals are bred from several generations until the population breeds true to the desired type due to the elimination of heterozygotes
• How can patterns of inheritance be analysed during inbreeding?

  Monohybrid crosses
• What is the result of inbreeding?

  an increase in the frequency of individuals who are homozygous for recessive deleterious alleles
• What is inbreeding depression?

  Reduced fitness or health problems resulting from mating between closely related individuals.
• Why can plants inbreed?

  Self-pollination