D1.3 - mutations 2 (5d)

Question 1

what are the 2 outcomes of insertion and deletion mutations?

Answer 1

there is a likelihood of polypeptides ceasing to function due to :
- frameshifts - deletion or insertion of 1 or 2 bases results in all codons being modified, resulting in amino acid changes
- major insertions or deletions - if sections of many amino acids are added to or removed from the protein, the 3D shape and it’s function will change

Question 2

what is an evaluation of using commercial genetic tests?

Answer 2

• commercial genetic tests can yield information about potential future health and disease risk
• one possible impact is that, without expert interpretation, this information could be problematic

Question 3

in what circumstances would an insertion or deletion not cause a frameshift mutation?

Answer 3

base insertions/deletions in multiples of 3, causing discrete amino acids to be added or removed

Question 4

what are germ cells?

Answer 4

germ cells use meiosis to produce gametes for sexual reproduction

Question 5

what will happen to the mutated genes within the germ cells?

Answer 5

mutated genes are passed onto the gametes and inherited by the next generation (or organism)

Question 6

what are somatic cells?

Answer 6

somatic cells use mitosis to divide and provide cells for tissue and organs within the body

Question 7

what can occur if mutations in somatic cell DNA means the process of mitosis becomes uncontrolled?

Answer 7

mutations in somatic cells are associated with cancer and the formation of tumors
- the mutation will be found in the DNA of all cells of the tumor

Question 8

what are the consequences of mutation in somatic cells?

Answer 8

mutations in somatic cells are not passed on to the next generation or organism

Question 9

what is mutation the source of?

Answer 9

gene mutation is the original source of all genetic variation

Question 10

what is the role of SNP’s in genetic variation?

Answer 10

the formation of single-nucleotide polymorphism causes new alleles to be formed

Question 11

what is the impact of most mutations for an individual?

Answer 11

most mutations are either harmful or neutral for an individual organism

Question 12

why are mutations essential at a species level in the long-term?

Answer 12

mutations are essential in the long-term for evolution by natural selection

Question 13

what is the process of evolution by natural selection?

Answer 13

1. mutations form new alleles and cause variation amongst organisms of the same species.
2. some mutations make organisms more suited to the environment
3. individuals that are better adapted survive and reproduce to produce offspring
4. individuals pass on mutation to their offspring
5. natural selection increases the frequency of characteristics and therefore alleles that make individuals better adapted to the environment