chapter 9.11 - 9.22

Question 1

incomplete dominance

Answer 1

heterozygote has three possible phenotypes

HH, Hh, hh

Question 2

multiple alleles

Answer 2

more than two alleles for a trait

Question 3

codominance

Answer 3

both alleles are expressed in heterozygote

Question 4

pleiotropy

Answer 4

one gene influences multiple traits

ex: homozygous recessive = abnormal hemoglobin AND several physical effects

Question 5

polygenic inheritance

Answer 5

two or more genes influence a trait

ex: human skin color and human height

Question 6

environmental effects

Answer 6

1. many characteristics result from a combination of genetic and environmental factors
2. nature (genetics) vs. nurture (environment)
3. only genetic influences are inherited

Question 7

gene linkage

Answer 7

genes located on the same chromosome

Question 8

why doesn’t gene linkage follow law of independent assortment

Answer 8

rather than single genes not influenced by each other, it’s entire chromosomes

Question 9

genetic/linkage maps

Answer 9

Used recombination frequencies to map the relative positions of genes on chromosomes
further apart two genes: less likely to cross over together
closer together two genes: more likely they will cross over together

Question 10

SRY gene

Answer 10

sex determining region of Y
triggers testes development
no SRY = ovaries

Question 11

sex-linked genes

Answer 11

genes located on sex chromosome

Question 12

why are recessive sex-linked traits expressed more frequently in women?

Answer 12

males have only one X, which is either dominant or recessive, they have no carriers

Question 13

X - chromosome inactivation

Answer 13

in XX, one X is inactivated

forms into Barr Body

Question 14

Barr Body

Answer 14

dense, compact region

Question 15

O blood type

Answer 15

ii