Natural Selection

Question 1

What is natural selection

Answer 1

When the allele codes for a characteristic that’s increases the chances of an organism surviving its frequency within a population can decrease

Question 2

How natural selection works

Answer 2

There’s differential reproductive success in a population so individuals that have an allele that make them more likely to survive will and reproduce and pass on their genes

Means that a greater proportion of the next generation has the better allele

More likely to survive and pass on their genes

Over generations this leads to evolution as the better alleles become more common in a population

Question 3

Types of adaptations in natural selection

Answer 3

Behaviour
Way an organisms acts

Physiological
Processes inside an organisms body

Anatomical
Structural features

Question 4

Two types of selection

Answer 4

Directional

Stabilising

Question 5

Directional selection

Answer 5

Where individuals with alleles for characteristics of an extreme type are more likely to survive

Question 6

Stabilising selection

Answer 6

Where individuals with alleles of characteristics in the middle range are more likely to survive and reproduce

Eg.
Birth weight. Smaller babies less likely to survive