cellular control

Question 1

what is a gene mutation

Answer 1

a random change to the genetic material

Question 2

when can mutations occur

Answer 2

can occur spontaneously during dna replication or a sresult of external factors such as tar and ionising radiation

Question 3

why are somatic and mitotic mutations not passed on?

Answer 3

Because they do not occur in cells that give rise to gametes, the mutation is not passed along to the next generation by sexual means.

Question 4

the 2 classes of dna mutation are

Answer 4

point mutaton

insertion or deletion

Question 5

3 different types of mutation

Answer 5

nonsense where the change in the base triplet becomes a termination.
misense- results in a significant change in the protein produced by altering its shape so its unable to carry out its function e.g sickle cell aneamia
silence- where a change in the base triplet still codes for the same amino acid

Question 6

regulation of gene expression

Answer 6

operon-length of dna made from structural genes and control sites

Question 7

how is aptosis controlled

Answer 7

by a range of cell signals 
cytokines
hormones
growth factors
nitric oxide acts as a