1: What causes diversity?

Question 1

Define standing genetic variation

Answer 1

= The no. of alternative alleles for a gene at a given locus in the pop.

Question 2

What is the level of standing genetic variation a predictor of?

Answer 2

The populations potential to evolve and adapt

Question 3

What maintains diversity?

Answer 3

Sex
Ploidy
Balancing selection
- Heterozygous advantage
- Frequency-dependent selection

Question 4

What do somatic mutations affect?

Answer 4

Individuals but NOT the pop.

Question 5

What can germline mutations affect?

Answer 5

Germline mutations affect the whole pop.

Question 6

Describe structural mutations

Answer 6

Changes happen at whole region level of chromosome

Question 7

Deletion mutation

Answer 7

region deleted

Question 8

Duplication mutation

Answer 8

region duplicated

Question 9

Inversion

Answer 9

region flipped
= Limit recombination

Question 10

Subsitution mutation

Answer 10

moved from one region to another

Question 11

Translocation mutation

Answer 11

regions swap

Question 12

Synonymous/silent mutations

Answer 12

codon changes but amino acid stays the same

Question 13

Non-synonymous

Answer 13

amino acid is altered

Question 14

Define missense mutations

Answer 14

change in single amino acid = alters protein function, reactivity etc.

Question 15

What do frame shift mutations effect?

Answer 15

impacts every codon downstream from mutation

Question 16

Describe the sex mutation bias

Answer 16

Sex bias: males generally have a higher mutation rate
Males produce more gametes so germline mutations are more common

Question 17

Define Independent assortment

Answer 17

Chromosomes randomly oriented in metaphase I → assortment of maternal + paternal copies is diff in the resulting gametes (Mendel’s Law)

Question 18

Define random fertilisation

Answer 18

Any sperm can fertilise any egg, so each zygote is a diff combo

Question 19

Define recombination

Answer 19

Shuffling of genetic material between maternal + paternal chromosomes during meiosis

Question 20

Give an example of heterozygous advantage

Answer 20

E.g Sickle Cell Anaemia
- Homozygous dominant = normal haemoglobin
- Heterozygous = sickle cell trait (minor health issues), malaria resistant
- Homozygous recessive = Severe sickle cell anaemia
- Heterozygote common in pop.s with high incidence of malaria

Question 21

What is frequency dependent selection?

Answer 21

the fitness of an allele changes depending on how common it is

Question 21

Describe positive frequency dependent selection

Answer 21

(strength in numbers)
Fitness & frequency + correlated
Fitness increases when alleles becomes more common

Question 22

Describe negative frequency dependent selection

Answer 22

(advantage in being rare)
Fitness & frequency negatively correlated
Fitness decreases when allele becomes more common