Topic 3 - Variation

Question 1

What are pedigree charts used for?

Answer 1

Scientists use these to show genetic disorders are inherited in a family, they can then use this to work out the probability that someone in the family will inherit a condition

Question 2

What’s a polygenic characteristic?

Answer 2

A characteristic influenced by two or more genes

Question 3

What is variation?

Answer 3

A difference in characteristics between organisms

Question 4

What causes genetic variation?

Answer 4

• Different alleles inherited during sexual reproduction
• mutations

Question 5

Give 3 examples of genetic variation?

Answer 5

• Natural hair colour
• eye colour
• blood group

Question 6

What is discontinuous variation?

Answer 6

That data that can only be a limited set of values and nothing in between
eg. Eye colour can be one colour or another nothing in between

Question 7

What is continuous variation?

Answer 7

Data that can be any value in a range (height or mass)

Question 8

Name 3 human phenotypes caused by genetic variation

Answer 8

• natural hair colour
• eye colour
• blood group

Question 9

Name 3 human phenotypes caused by the environment

Answer 9

• scars
• tattoos
• accents

Question 10

Name 2 factors affected by both the environment and genetic variation

Answer 10

• skin colour (can be tanned)
• weight (availability of food)