Download Quiz 13 Name: 1. Suppose there are two alleles of a gene, called A

Quiz 13
Name:__________________________
1. Suppose there are two alleles of a gene, called A and a, and A is dominant to a. In a cross, Aa x Aa,
among the offspring there are _____ possible genotypes and _____ possible phenotypes.
A) 4, 3
B) 3, 2
C) 2, 1
D) 1, 2
E) 2, 4
2. Imagine crossing a pea heterozygous for flower color (white vs. purple) and seed color (yellow vs.
green) with a second pea homozygous for flower color (white) and seed color (yellow). What types of
gametes will the first pea produce?
A) two gamete types: white/white and purple/purple
B) two gamete types: white/yellow and purple/green
C) four gamete types: white/yellow, white/green, purple/yellow, purple/green
D) four gamete types: white/purple, yellow/green,white/white, and purple/purple
E) one gamete type: white/purple/yellow/green
3. Humans cells have
A) one allele for any given trait, either from the mother or the father
B) one allele for any given trait, always from the mother
C) one allele for any given trait, always from the father
D) two alleles for any given trait, one from the mother and one from the father
4. Disorders caused by recessive, sex-linked (X) alleles should be most commonly expressed in:
A) male humans (XY)
B) female humans (XX)
5. If we assume that in dogs long legs are dominant to short then, if a heterozygous long-legged dog
mates with a homozygous short-legged dog, what is the probability that the offspring will be short?
A) 1
B) 1/2
C) 1/4
D) 1/6
E) 0
6. A woman has three sons. The chance that her next child will be a daughter is
A) 1.
B) 0.
C) 1/4.
D) 1/2.
E) 3/4.
7. Males are more often affected by sex-linked traits than females because
A) males only have one X chromosome.
B) X chromosomes in males generally have more mutations than X chromosomes in females.
C) mutations on the Y chromosome often worsen the effects of X-linked mutations.
D) male hormones such as testosterone often alter the effects of mutations on the X chromosome.
E) female hormones such as estrogen often compensate for the effects of mutations on the X.
8. Red-green color blindness is an X-linked recessive trait (b) in humans. Two people with normal
color vision have a color-blind son. What are the genotypes of the parents?
A) XbXb and XbY
B) XBXB and XbY
C) XbXb and XBY
D) XBXB and XBY
E) XBXb and XBY
9. Dependent assortment:
A) Occurs when genes are located on different chromosomes.
B) Occurs when genes are located close together on the same chromosome.
10. Genes are more closely linked (more likely to travel together) when they are:
A) close to one another on the same chromosome
B) far from one another on the same chromosome
C) close to one another on different chromosomes
D) far from one another on different chromosomes