Selection

Question 1

Stabilising selection

Answer 1

1. Selection against both extremes
2. Only mean phenotype will have reproductive success
3. Allele for mean phenotype are passed to future generations
4. Over time frequency of mean alleles increases

Question 2

Directional selection

Answer 2

1. Selection for only one extreme
2. Individuals with advantageous allele have increased reproductive success
3. Alleles for one extreme are passed on to future generations
4. Over time frequency of this extreme allele increases

Question 3

Normal distribution

Answer 3

Within population there is a wide range of variations of phenotypes due to mutations of genes.

Question 4

Explain how selection occurs in living organisms

Answer 4

1. Variation due to mutation
2. Different selection pressures
3. Selection for advantageous allele
4. Differential reproductive success
5. Leads to change in allele frequency
6. Occurs over long time period

Question 5

What is a allele

Answer 5

Different form of a gene