Topic 4---B: Diversity and Selection- 3. Genetic diversity

Question 1

Genetic diversity (definition)

Answer 1

It is the number of different alleles of genes in a species or population.

Question 2

What does a large number of different alleles in a population mean?

Answer 2

A large variety of different characteristics

Question 3

What may happen if a population has a low genetic diversity?

Answer 3

It might not be able to adapt to a change in the environment and the whole population could be wiped out by a single event. e.g. ( disease )

Question 4

How can genetic diversity within a population be increased?

Answer 4

• Mutations in the DNA forming new alleles (some can be advantageous and some can lead to problems)
• Different alleles being introduced into a population when individuals from another population migrate into it and reproduce (gene flow)

Question 5

Genetic bottlenecks

Answer 5

• Its an event that causes a big reduction in a population
• Leading to organisms dying before they reproduce
• This reduces the number of different alleles in the gene pool and reduces genetic diversity
• The survivors reproduce and a large population is created from a few indivduals (genetic diversity is reduced)

Question 6

The founder effect

Answer 6

• Occurs when a few organisms from a population start a new colony and there are only a small number of different alleles in the initial gene pool and genetic diversity is greatly reduced
• Original population maintains a high level of genetic diversity