Mutations

Question 1

What can mutations in genes and chromosomes can result from errors in?

Answer 1

-DNA Replication (point and frameshift mutation)
-Cell division (non- disjunction)
-Damage by mutagens (physical, including UV radiation, ionising radiation and heat and chemical)

Question 2

Explain point and frameshift mutations.

Answer 2

A point mutation is where one nucleotide base is switched for another, thus possibly changing the amino acid produced. A frameshift mutation is where an insertion or deletion of a nucleotide base has occurred resulting in a different series of amino acids.

Question 3

Explain how non-disjunction leads to aneuploidy.

Answer 3

Non-disjunction occurs when homologous chromosomes or sister chromatids don’t separate in anaphase 1 or 2 of meiosis. This results in one gamete receiving two copies of the same DNA and the other gamete not receiving it at all, furthermore, leading to aneuploidy as the respective gametes will have an incorrect number of chromosomes.

Question 4

Describe how inherited mutations can alter the variations in the genotype of offspring.

Answer 4

Mutations can alter certain traits by absolutely silencing a particular gene thus producing genotypic variation.