Polygenic (3.15)

Question 1

Give the definition of variation and explain the difference between continuous and discontinuous variation

Answer 1

This is differences between individuals of the same species due to biological and environmental factors. This includes discontinuous and continuous variation. Continuous = data in range whereas discontinuous = data in groups

Question 2

Give the definition of polygenic inheritance

Answer 2

Where a single characteristic is controlled by multiple genes. This gives rise to continuous variation in the peg phenotype (human skin colour)

Question 3

Explain how human height is evidence for polygenic inheritance

Answer 3

As it involves multiple genes that each have a say in the overall outcome

Question 4

Explain how skin colour is evidence for polygenic inheritance

Answer 4

This trait is determined by at least three genes and other genes are also thought to influence skin color. Skin color is determined by the amount of the dark color pigment melanin in the skin

Question 5

Explain how hair colour in Siamese cats/Himalayan rabbits is evidence for polygenic inheritance

Answer 5

As darker hair grows in cooler parts of the animals body it shows that multiple genes have a say in the final outcome in the phenotype.