Multifactorial Inheritance

Question 1

What is multifactorial inheritance?

Answer 1

Process by which a disease results from the effects of a number of abnormal genes and environmental factors

Question 2

What type of patterns are seen with multifactorial inheritance?

Answer 2

Typical Mendelian inheritance is not observed. Interaction of multiple genes and environmental factors result in different presentations

Question 3

What is the basis of polygenic inheritance?

Answer 3

Over one fourth of all genes in normal humans hav polymorphic alleles

Question 4

Relationship b/w Syx and number of mutant genes?

Answer 4

Proportional

Question 5

In polygenic inheritance, how does the expression in earlier siblings affect the likelihood of the trait’s expression in later siblings?

Answer 5

The chance that it will recur is doubled

Question 6

How is a medelian trait likelihood of expression in a sibling affected if the first child has the trait?

Answer 6

The likelihood does not chang

Question 7

In multifactorial inheritance, how is severity of a defect associated with risk of transmission

Answer 7

Positive relationship

Question 8

In a polygenic trait with gender predilection, what is the rule of thumb?

Answer 8

A membere of the less commonly affected sex has a much greater probability of transmitting the defect