Chapter 4- Part 2

Question 1

Complete penetrance

Answer 1

all identical genotype shows expected phenotype

Question 2

incomplete penetrance

Answer 2

some identical genotypes do not show any of the expected phenotype

Question 3

Expressivity

Answer 3

the degree to which a penetrant gene is phenotypically expressed

Question 4

What type of expressivity does Neurofibromatosis echibit

Answer 4

Variable expressivity (severity varies) with 50-80% penetrance.

Question 5

What do the BRCA genes code for?

Answer 5

a protein that prevents cells form growing and dividing uncontrollably (acts as a tumor suppressor)

Question 5

What do mutations in BRCA genes tend to cause?

Answer 5

breast cancer

Question 6

what are autosomes

Answer 6

any chromosome that is not a sex chromosome

Question 7

Limited sex inheritance

Answer 7

• genes on autosomes
• phenotype that appears in only one sex (facial hair)

Question 8

Influenced sex inheritance

Answer 8

• genes on autosomes
  -appear in both sexes but the frequency in each sex is different

Question 9

Linked Sex inheritance

Answer 9

• X or Y chromosomes

Question 10

Cleft lip and palate are examples of

Answer 10

sex influenced traits

Question 11

Systemic lupus Erythematosus

Answer 11

Sex influenced trait that expresses mostly in women

Question 12

Microchimerism

Answer 12

the presence of two genetically distinct cell populations in the same individual

Question 13

Explain how age can affect expression

Answer 13

Not all genes are active at the same time, activation and deactivation occurs as the organism ages

Question 14

Temperature affecting traits

Answer 14

some alleles may encode temp sensitive mutant proteins (color of Siamese cats)