4.4 - Genetic diversity and adaptation

Question 1

Define genetic diversity

Answer 1

The number of different alleles of genes in a population

Question 2

Describe the relationship between genetic diversity and natural selection

Answer 2

Generic diversity is a factor enabling natural selection to occur

Question 3

Describe the principles of natural selection

Answer 3

Random mutation can result in new alleles of a gene
Many mutations are harmful but in certain environments the new allele of a gene may benefit its possessor, so increased reproductive success
Advantageous allele inherited by members of the next generation
Over many generations, allele frequency increases in population

Question 4

What is stabilising selection and give an example

Answer 4

Favours average phenotype
E.g human birth weights

Question 4

What is directional selection and give an example

Answer 4

Favours one extreme phenotype
E.g antibiotic resistance in bacteria

Question 5

Types of adaptations caused by natural selection

Answer 5

Anatomical - physical structures
Physiological - processes within the body
Behavioural - actions (can be learnt or inherited)