3.4.4 Genetic diversity and adaptation

Question 1

Define genetic diversity

Answer 1

The number of different alleles of a gene within a population

Question 2

Define evolution

Answer 2

Change in the frequency of alleles over many generations to enable a species to be better adapted to their environment

Question 3

Describe the process of natural selection

Answer 3

New allele for gene created by random mutation
New allele may give the animal an advantage so are more likely to survive and breed
They then reproduce and pass on this advantageous allele to their offspring
Repeats for generations and frequency of the allele increases within the population

Question 4

Explain the two types of selection

Answer 4

Directional - one of the extremes has the selective advantage due to change in environment so modal trait changes with numbers around the mean falling and numbers at the extremes increasing
Stabilising - modal trait has the selective advantage and no change in the environment, number with modal trait increases and numbers at the extreme decreasing causing SD to decrease