Mutation

Question 1

How can a mutation produce a non functional enzyme

Answer 1

-mutation in base so different triplet
-changes amino acid sequence
-H-bonds,ionic bonds disulphide bridges change/ form in different places
-different tertiary structure/active site
-no longer complementary to substrate
-no es complexes

Question 2

Why might all body cells have a mutation 2m

Answer 2

-mutation in gamete
-all cells from mitosis
Or
-all cells derived from a single cell by mitosis
-producing genetically identical cells

Question 3

Defect causes blood to flow from aorta to pulmonary artery, why is this bad

Answer 3

-less oxygenated blood in aorta
-less o2 to tissue/cells
-for AEROBIC respiration
-tissue can’t grow
-dies

Question 4

How might resistance to an antibiotic become widespread in a bacterial population following a gene mutation

Answer 4

1. Frequent use of antibiotic creates selection pressure/ antibiotic kills bacteria;
2. Bacteria with mutation/ resistance have (selective) advantage over others / described;
3. (Survive to) reproduce
4. Pass on advantageous allele/ mutated allele in greater numbers;
5. Frequency of (advantageous allele increases in subsequent generations

Question 5

When in the cell cycle are mutations most likely to occur?

Answer 5

Interphase
DNA replication is occurring – spontaneous mutations most likely at this point