Variation

Question 0

What is discontinuous variation?

Answer 0

• distinct groups or categories
• qualitative
• affected by the genotype (monogenic - influenced by only one gene)
• epistasis limits the range of variation
• e.g. Eye colour, blood group

Question 1

What is continuous variation?

Answer 1

• no distinct groups or categories
• quantitative
• affected by the environment and genotype
• polygenic - influenced by many genes
• influenced more by the environment
• e.g. height, weight

Question 2

What factors contribute to phenotypic variation?

Answer 2

• environment

* genotype

Question 3

What is polygenic inheritance?

Answer 3

Many phenotypic characteristics are controlled by more than one gene and are therefore affected by alleles at many loci as well as the environment

Question 4

Why is variation essential in selection?

Answer 4

• Essential in order for evolution to occur by natural selection
• if there was no variation no individuals would be better adapted than any others and selection could not occur, they would not survive and reproduce passing on advantageous alleles to their offspring allowing the species to carry on