evolution

Question 1

what is evolution?

Answer 1

the changes in organisms over generations as a result of genomic variations.

Question 2

what is natural selection?

Answer 2

the non-random increase in frequency of DNA sequences that increase survival and the non-random reduction in the frequency of deleterious sequences.

Question 3

describe the two types of gene transfer

Answer 3

Horizontal gene transfer is where genes are transferred between individuals in the same generation.

Vertical gene transfer is where genes are transferred from parent to offspring as a result of sexual or asexual reproduction.

Question 4

what are the 3 types of selection?

Answer 4

directional, stabilising and disruptive

Question 5

what is directional selection?

Answer 5

one extreme of the phenotype range is selected for.

Question 6

what is stabilising selection?

Answer 6

an average phenotype is selected for and extremes of the phenotype range are selected against.

Question 7

what is disruptive selection?

Answer 7

two or more phenotypes are selected for.

Question 8

what is speciation?

Answer 8

formation of new biological species as a result of isolation, mutation or selection

Question 9

what is a species?

Answer 9

a group of organisms capable of interbreeding and producing fertile offspring, and which does not normally breed with other groups.

Question 10

what is allopatric speciation?

Answer 10

a new species is formed due to the isolation of a population by a geographical barrier

Question 11

what is sympatric speciation?

Answer 11

a new species is formed due to the isolation of a population by either a behavioural or ecological barrier