Download Zoo/Bot 3333

Zoo/Bot 3333
Genetics
Quiz 2
9/28/07
For answers, please click here
1. Which of the following ratios show independent assortment?
a) 9:3:3:1; b) 9:7; c) 9:3:4; d) all of the above; e) none of the above.
2. In the common daisy, the genes A and a and B and b represent two pairs of alleles
acting on flower color. A and B are required for color. What would be the predicted ratio
of colored to colorless among the progeny of an F1 cross, where the parentals were two
colorless plants, one homozygous for A and the other homozygous for B?
a) 9:3:3:1; b) 9:7; c) 9:3:4; d) 12: 3: 1; e) none of the above.
3. In corn, three dominant genes are necessary for aleurone color. The genotype B_D_R_
is colored. Any homozygous recessive for one gene is colorless. The ratio of colored to
colorless individuals in the cross BbDdRr  BbDdRr would be:
a) 9:7; b) 16:1; c) 13:3; d) 27:37; e) none of the above.
4. An inherited state that is determined by segregating alleles of many different genes,
and whose interaction with each other and the environment produces a phenotype
exhibiting many intermediate forms, is termed:
a) a quantitative trait; b) codominance; c) incomplete dominance; d) phenocopy; e) none
of the above.
5. A person who has type O blood has
a) anti-A antibodies; b) anti-B antibodies; c) no surface antigens on their RBCs; d) all of
the above are correct; e) only two of the above are correct.
6. In humans, the gene for red-green colorblindness is 3 map units from the gene for
hemophilia A. A woman whose mother is colorblind and whose father has hemophilia A
is pregnant with a boy and wants to know the probability that he will have normal vision
and blood clotting. What is the probability?
a) 0.03; b) 0.15; c) 0.485; d) 0.47; e) 0.015.
Questions 7-8 pertain to the following: Females heterozygous for the
recessive second chromosome mutations cn, px, and sp are mated to
a male homozygous for all three mutations. The offspring are as
follows:
px sp cn
px sp +
px + cn
px + +
+ sp cn
+ + cn
+++
total
1,461
3,497
1
11
9
3,482
1,539
10,000
7. True or false: This data set indicates that all three genes are linked and that px is the
middle gene.
8. The map distance between the px and sp loci is:
a) 30 map units; b) 3 map units; c) 21 map units; d) 0.21 map units; e) the loci are not
linked.
9. A testcross between an individual who is trihybrid for three different gene loci (K/k,
V/v, I/i) and an individual homozygous recessive for all three loci yields the following
progeny:
KVi 214
kVi 226
KVI 26
kVI 28
Kvi 30
kvi 36
KvI 218
kvI 222
Which of the following are true?
a) the three gene loci are linked and I is the middle gene; b) the I and K genes are located
on the same chromosome and separated by 50 map units; c) the V locus is located 12 map
units from the I locus; d) all of the above; e) none of the above.
10. In Neurospora the cross between AB x ab was made and 100 asci were scored with
the following results.
In this cross, the distance between the A and B loci can be estimated to be:
a) 7 map units; b) 14 map units; c) 22 map units; d) greater than 32 map units; d) the A
and B genes are not linked.