Module 3: Multifactorial Inheritance

Question 1

Multifactorial Inheritance

Answer 1

A disease that is caused by a mix of genetic and environmental factors

Question 2

Models of multifactorial inheritance

Answer 2

• Polygenic model

- Threshold model

Question 3

Threshold Model

Answer 3

• A certain number of genetic and environmental factors to be affected
• Threshold models are graphs that illustrate this
• Males have to have fewer genetic conditions to express the condition

Question 4

Monozygotic Twins

Answer 4

• Raised together (similar env’t)

- Same genetics (identical twins)

Question 5

Dizygotic Twins

Answer 5

• Fraternal twins - same genetics as full siblings

- Similar env’t

Question 6

(True/False) Genetic testing for “the” eye color gene can reliably determine eye color

Answer 6

False

Question 7

What would you infer from a twin study that revealed a trait had a low concordance in both MZ & DZ twins?

Answer 7

Few genetic factors contribute to the condition

Question 8

What do family studies rely on to determine if a multifactorial condition has a large genetic component?

Answer 8

Families with multiple members affected with the condition