Patterns of inheritance and variation

Question 1

Outline chlorosis

Answer 1

Reduced production of chlorophyll causing a yellowish colour

Environmental

1) Lack of light - toy left on the lawn, absence of lights causes plants to save resources and stop chlorophyll production

2) Mineral deficiencies - lack of magnesium or iron
- Iron is needed as a cofactor for some enzymes that make chlorophyll

3) Virus infections - they interfere with the metabolism of plants, plants can no longer support the production of chlorophyll

Question 2

Animal body mass

Answer 2

Genetic and environmental

Question 3

What is continuous variation?

Answer 3

A characteristic that can take any value within a range

Question 4

What is discontinuous variation?

Answer 4

A characteristic that can only appear in specific values

Question 5

What are the causes for continuous variation?

Answer 5

Environmental and genetic

Question 6

What are the causes for discontinuous variation?

Answer 6

Genetic

Question 7

How many genes control continuous variation?

Answer 7

Polygenetic

Question 8

How many genes control discontinuous variation?

Answer 8

One or two genes

Question 9

What is the equation for recombination frequency?

Answer 9

Recombination frequency = number of recombinant offspring ÷ total number of offspring