Genetics and

1. Genetics and Society

2. Give an example of a plant and an animal where a characteristic has been enhanced by selective breeding Give an example of a chromosomal mutation in a plant or animal which is of economic importance State that amniocentesis can be used to detect chromosomal abnormalities before birth Give an example of a factor which can affect the mutation rate Describe a human condition such as Down’s syndrome, which is caused by a chromosome mutation

3. Selective breeding is choosing parents with the desired characteristic to produce offspring with the same desirable trait. In farming, this is economically important, as farmers will have more product to sell. Mutation – a change in the genetic material of an organism Mutations can be sped up by mutagenic agents such as radiation, or certain chemicals (e.g., mustard gas)

4. Some mutations can be useful, e.g., some plants have more than one set of chromosomes allowing them to produce more fruit. However, some mutations have an adverse affect. E.g., Down’s Syndrome. Down’s syndrome affects the mental development of a person, and is caused by having an extra copy of chromosome 21.

5. Amniocentesis can be carried out to detect if a foetus has any mutations. Cells from foetus will be present in amniotic fluid. A sample is taken, cells are grown, and chromosomes are then counted.