Revision:Applied genetics

Define genetic screening

Testing a population for the presence or absence of a gene.

Discuss three advantages and disadvantages of genetic screening

  • Advantages
    • Lessen the devastating impact of genetic disease
    • Identification of persons who have genetically determined susceptibilities to specific environmental agents
    • Insurance Companies can give lower premiums
  • Disadvantage
    • Can stigmatise and emotionally traumatize those who learn that they are carriers of genetic defects
    • Invasion of privacy
    • Has the potential of being used to dictate who may or may not reproduce

State that the Human Genome project is an international cooperative venture to sequence the complete human genome

Discuss two possible advantages of this project

  • Understanding of many genetic diseases
  • Genome libraries
  • Production of gene probes to detect sufferers and carriers of genetic diseases
  • Production of pharmaceuticals based on DNA sequences

Define clone

A group of organisms of identical genotype / a group of cells descended from a single parent cell.

Outline a technique used in the cloning of farm animals

  • Early division of a fertilised egg produces 8 cells each of which would give rise to an embryo (totipotency).
  • After in vitro fertilisation processes the 8 resultant separated embryos can be transferred to surrogate mothers (e.g cattle or sheep) to continue using selected prime animals for the production of gametes
  • At present used for genetically manipulated animals to produce pharmaceuticals

Discuss the ethical issues of cloning human embryos

  • Happens naturally in monozygotic twins
  • In vitro fertilisation of twins unacceptable?
  • Selection of those fit to be cloned
  • Eugenics and super-race?

Discuss the results of crop plant and animal breeding

  • Breeding for disease resistance
  • Increased food production
  • Higher yields of milk/wool/protein
  • Breeding plants that can spread