4-4 Genetic diversity and adaptation

Question 1

What is genetic diversity?

Answer 1

• Genetic diversity is the total number of different alleles in the population.

Question 2

What is a population?

Answer 2

• A population is a group of individuals of the same species that live in the same place and are able to breed with one another to produce fertile offspring.

Question 3

What is a niche?

Answer 3

• The niche of a species is its role within the environment.

Question 4

What is natural selection?

Answer 4

• The process of natural selection is where fitter individuals who are better adapted to the environment survive and pass on the advantageous genes to future generations.

Question 5

What is evolution?

Answer 5

• Evolution is the process by which the frequency of alleles in a gene pool changes over time as a result of natural selection.

Question 6

How does natural selection result in evolution?

Answer 6

• There’s a variety of different phenotypes within a population.
• An environmental change occurs and as result of that the selection pressure changes.
• Some individuals possess advantageous alleles which give them a selective advantage and allow them to survive and reproduce.
• The advantageous alleles are passed on to their offspring.
• Over time, the frequency of alleles in a population changes and this leads to evolution.

Question 7

What is selection?

Answer 7

• Selection is the process by which individuals that are better adapted to their environment are more likely to survive and breed.

Question 8

What are the two types of selection?

Answer 8

• Directional selection, directional selection occurs when environmental conditions change and the phenotypes best suited to the new conditions are more likely to survive, as a result these individuals will breed and produce offspring, overtime the mean of the population will move in the direction of these individuals.
• Stabilising selection, in stabilising selection the phenotypes with successful characteristics are preserved and those of greater diversity are reduced, this selection doesn’t occur due to changes in the environment, if the environment stays the same then the individuals closest to the mean are favoured because they have the alleles that have given them the survival advantage, the furthest from the mean are selected against.

Question 9

What are the three types of adaptation?

Answer 9

• Anatomical adaptation, physical changes.
• Behavioural adaptation, behavioural changes.
• Physiological adaptation, processes inside an organisms body that change.