University of South Florida PCB 3063 Quiz 5 1)Duplicate gene action produces a phenotypic ratio of 9:3:3:1 9:3:4 12:3:1   15:1 none of these choices   2

University of South Florida

PCB 3063

Quiz 5

1)Duplicate gene action produces a phenotypic ratio of 9:3:3:1

9:3:4

12:3:1

  15:1

none of these choices

2. Complementation epistasis produces a phenotypic ratio of 9:3:4

  9:7

15:1

13:3

9:3:3:1

3. Dominant epistasis produces a phenotypic ratio of 9:3:4

  12:3:1 15:1

13:3

9:6:1

4. The genes R, E and D are independently assorting and control production of red pigment as follows (recessive alleles are not functional)

precursor -- (R) --> white -- (E) --> yellow -- (D) --> red

RREEDD and rreedd individuals are crossed, and their offspring are testcrossed. What proportion of the F2 progeny is expected to be red?

1/2

1/4

  1/8 1/16

none of these choices

5. Refer to the pathway of question 22. If RrEEDd and RrEEDd individuals are crossed, what proportion of the progeny is expected to be yellow?

1/4

  3/16 3/8

5/16

1/2

6. Tail and neck plumage in domestic fowl is an example of          inheritance that is under the control of a(n)        gene.

  sex-limited ; autosomal

sex-limited ; Y-linked sex-influenced ;

Y-linked sex-influenced ; X-linked

sex-influenced ; autosomal

7. In the “sheperd’s purse” weed, Capsella bursa-pastoris, fruit shape is governed by two independently assorting genes, A and B. Double recessive (aabb) fruits are narrow-shaped (ovoid). The presence of at least one dominant allele at either locus results in a heart-shaped (triangular) fruit. What is the expected phenotypic ratio in the offspring of an AaBb x aabb cross?

1 heart-shaped:3 narrow-shaped

1 heart-shaped:15 narrow-shaped

  12 heart-shaped:4 narrow-shaped

13 heart-shaped:3 narrow-shaped

15 heart-shaped:1 narrow-shaped

8. In a particular animal, coat color is under the control of two independently assorting genes, A and B. Animals can be gray (A-B-), cinnamon (A-bb), black (aaB-) or brown (aaabb). Which of the following crosses will yield offspring in a ratio of 3/4 gray : 1/4 cinnamon?

AABB x Aabb AaBB x AAbb

  AABb x aaBb AaBb x aabb

none of the above

9. In Suffolk sheep, a single locus with two alleles controls the presence or absence of horns, with horned (H) being dominant to hornless (h). In males the genotypes HH or Hh have horns, and hh is hornless; in females the genotype HH has horns, and Hh or hh are hornless. Two hornless sheep are mated and produce a male lamb with horns. What are the genotypes of the hornless parents?

Male HH and female Hh

  Male hh and female Hh

Male Hh and female hh

Male Hh and female Hh

10. Genes A, B, and C are independently assorting and control production of a black pigment. The dominant alleles A, B and C code for functional enzymes whereas the recessive alleles a, b, and c code for nonfunctional enzymes. An individual of genotype AABBCC is crossed with one of genotype aabbcc, and the resulting F1 individuals are cross-fertilized. For the following pathway state what proportion of the F2 progeny is colorless? Colorless ----A---> colorless

----B---> colorless ----C---> Black 1/64

9/64

27/64

  37/64

none of these choices

11. In dragons, coat color is under the control of two independently assorting genes, Y and B. A dragon can be green (B-Y-), blue (B-yy), yellow (bbY-) or white (bbyy). This is an example of codominance

incomplete dominance variable

expressivity

  epistasis

environmental effect

12. Refer to the information in question 40. How many different genotypes are possible for green dragons?

1

2

3

  4

none of the above

13. A pattern bald woman is married to a pattern bald man. They are expecting a girl. What is the probability that she will develop pattern baldness?

0

1/2

1/4

1/1

  cannot determine from the given information

14. Refer to the information in question 40. What proportion of the cross BbYy x Bbyy is expected to be colored?

1/2

1/4

1/8

3/4

  7/8

15. Genes A, B, and C are independently assorting and control production of a black pigment. The dominant alleles A, B and C code for functional enzymes whereas the recessive alleles a, b, and c code for nonfunctional enzymes. An individual of genotype AABBCC is crossed with one of genotype aabbcc, and the resulting F1 individuals are cross-fertilized. For the following pathway state what proportion of the F2 progeny is colorless? Colorless ----A---> colorless

----B---> Black | C (inhibitor of B) 1/64

9/64

27/64

37/64

  none of these choices