Genetic Diversity And Natural Selection

Question 1

What are 2 ways that genetic diversity increases

Answer 1

• mutations in DNA, forming new alleles
• different alleles being introduced into the population from other individuals from other populations

Question 2

What is gene flow

Answer 2

When different alleles are being introduced into a population from other individuals in another population

Question 3

What is a population

Answer 3

Group of organisms of one species living in a particular habitat

Question 4

What is a genetic bottleneck

Answer 4

It is an event that causes a big reduction in a population

Question 5

What is the gene pool

Answer 5

The complete range of alleles in a population

Question 6

What is the founder effect

Answer 6

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
- this causes an allele that was rare to be more common which may lead to an increase in genetic disease

Question 7

what is natural selection

Answer 7

when an allele codes for a characteristic that increases the chances of an organism surviving, allowing the frequency within the population to increase

Question 8

what is evolution

Answer 8

the gradual change in species over time

Question 9

what are two types of natural selection

Answer 9

directional selection and stabilising selection

Question 10

what is directional selection

Answer 10

it is where individuals with alleles for characteristics of an extreme type are more likely to survive and reproduce

e.g bacteria evolving to antibiotic resistance

Question 11

what is stabilising selection

Answer 11

it is where individuals with alleles for characteristics toward the middle of the range are more likely to survive and reproduce

e.g human birth weight