Genetic Diversity and Adaptation

Question 1

What is genetic diversity?

Answer 1

the total number of different alleles in a population

Question 2

What advantage does high genetic diversity provide?

Answer 2

the stability to adapt to a change in the environment, allows natural selection to occur

Question 3

Explain how natural selection results in the development of new characteristics

Answer 3

• mutations -> new alleles
• some alleles provide a selective advantage, meaning they are more likely to survive and reproduce
• the offspring receive the allele and pass it to next generation, allele frequency increases

Question 4

What is directional selection?

Answer 4

Individuals with phenotypes suited to the environment will survive and pass on alleles, the mean of population will shift towards these phenotypes

Question 5

When does directional selection occur?

Answer 5

when there is a change to the environment

Question 6

Give an example of directional selection

Answer 6

Antibiotic resistance.

Question 7

What is stabilising selection?

Answer 7

Individuals closest to the mean are favoured, any with new characteristics are selected against. Low genetic diversity

Question 8

When does stabilising selection occur?

Answer 8

when the environment remains the same

Question 9

Give an example of stabilising selection?

Answer 9

birth weight

Question 10

What are 3 types of adaptation?

Answer 10

behavioural (actions) , physiological (body processes) and anatomical (body structure)

Question 11

What is an allele?

Answer 11

different form of the same gene, found at the same locus

Question 12

How has the use of antibiotics led to antibiotic resistant bacteria being contracted in hospitals?

Answer 12

• some bacteria have allele for resistance
• non-resistant die/antibiotics is selection pressure
• more antibiotics used in hospitals/high frequency of resistance allele