Selection

Question 1

What is selection

Answer 1

The process by which organisms that are better adapted to their environment tend to survive and breed, while those that are less well adapted tend not to

Question 2

What is directional selection

Answer 2

Where individuals with alleles for characteristics of an extreme types are more likely to survive and reproduce. This could be in response to an environmental change.

Question 3

What is stabilising selection

Answer 3

Where individuals with alleles for characteristics towards the middle of the range are more likely to survive and reproduce. It occurs when the environment isn’t changing

Question 4

Which selection preserves the characteristics and which changes characteristics

Answer 4

Directional - changes

Stabilising - preserves

Question 5

In directional selection how does the mean overtime then move in the direction of these individuals

Answer 5

These will possess a phenotype more suited to the new conditions. These will be more likely to survive and breed. There contribute more offspring to the next generation of other individuals, overtime moving the mean in the direction of these individuals

Question 6

Which phenotypes does stabilising selection eliminate

Answer 6

Phenotypes of extremes

Question 7

Natural selection results in species better adapted to the environment that they live in. What are the 3 types of adaptations ?

Answer 7

Anatomical - structural features of an organisms body that increase its chance of survival

Physiological- processes inside an organisms body that increase its chance of survival

Behavioural- ways an organism acts that increase its chance of survival and reproduction