Genetic Variation

Question 1

Causes of GV

Answer 1

1. sexual reproduction- genetic recombination, crossing over of chromosome
2. mutations- can be passed on if cells that make sperm/eggs have mutations

Question 2

types of mutations

Answer 2

PIGG
1. point inversions (insertions/deletions INDELS)
2. inversions
3. gene duplications
4. genome duplications

Question 3

point mutaions

Answer 3

transitions more common than transversions.
genetic code redundant, some changes will not alter encoded a.a

Question 4

sickle cell anaemia

Answer 4

abnormal beta chains
stick together
deoxygenated RBC

Question 5

inversions

Answer 5

naturally, induced by radiation
heterozygotes prevent crossing over

Question 6

gene duplications

Answer 6

retrotransposition
unequal crossing over
TS- copy and paste (retrotransposon) , cut and paste (DNA transposon) , hundreds around the genome

Question 7

heterozygous advantage

Answer 7

1. inbreeding depression (bad to be highly homo)
2. over-dominance (good to be highly hetero)

Question 8

inbreeding avoidance

Answer 8

DEKD out
1. dispersal
2. extra-pair paternity
3. kin recognition + avoidance
4. delayed maturation

Question 9

dispersal

Answer 9

eg white-footed mouse goes away from nest to avoid inbreeding

Question 10

extra-pair paternity

Answer 10

eg superb fairy wrens females mate outside the pair with other males

Question 11

kin recognition + avoidance

Answer 11

eg storm petrels can recognise who is distantly/closely related

Question 12

delayed maturation

Answer 12

eg wolves wont be sexual active until away from mother

Question 13

over-dominance

Answer 13

heterozygotes more fit than homo
eg warfarin resistance in rats
1. homo susceptible rats killed by poison
2. homo rats that were resistant had vitamin K defiency
3. hetero are resistant to poison and have vit k deficiency

Question 14

local adaptation

Answer 14

traits vary geographically
eg biotic/ abiotic
eg clines, change in character over distance and vary body size
eg peppered moths