Biol 1003 Fall 2013
Genetics Quiz (10 Points)
Name ____________________________________
Section ________
In a species of dog, coat color can be either light (figure I), or dark (figure II). Coat color is controlled by a
single gene with two alleles, R and r. Beside each dog is one of its cells with the chromosome pair which
carries the gene that influences coat color. Questions 1-3 refer to these two diagrams.
I. – light coat
r
II. – dark coat
r
R
r
1. (0.5 point) Beside each dog you see one of the cells in its
body. Are the cells shown above haploid or diploid?
2. (0.5 point) The relationship between the two
chromosomes in the cells is best describes as:
a) Hemizygous
b) Homozygous
c) Heterozygous
d) Homologous
3. (0.5 point) With respect to the coat color character trait,
what is the phenotype of dog #II (on the right)?
4. The recessive white coat allele codes for a truncated, non-functional, pigment protein while the
dominant, brown coat, allele codes for a longer, fully functional, protein. Using the chart on the right,
translate the following two mRNA sequences (0.5 points)
5. Indicate which sequence is the dominant allele “R” and which is the recessive “r” allele (0.5 points).
1) AUGUAACAG
2) AUGUCACAG
Amino Acid Sequence:_________________
__________________
Allele: __________
Allele:__________
In this species of frog, body pattern (plain vs. spotted) is controlled by a single
autosomal gene.
Questions 6-8 refer to this cross in this species of frog. Note that the parents and
the offspring on the right are spotted, while the offspring on the left is smooth.
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6. (0.5 point) What is the genotypes of:
Male parent (left) ___________________
Female parent (right)_________________
7. (0.5 point) What are the genotypes of the F1 (the offspring) individuals, and how many of each
genotype are expected? (hint: start with a Punnett square)
8. (0.5 point) Cross a heterozygous frog with a homozygous recessive frog. Draw and fill in the
Punnett square for this cross:
Questions 9-11 refer to the following scenario. Judy is in 4H. She chooses to raise bunnies to show at the
County fair. Judy has looked at the winners for best in show for the past ten years. For all 10 years, all of
the winning bunnies were tan. Therefore, Judy buys the two prettiest tan bunnies available. After Judy
mates her two new bunnies, Nibbles and Sir Hops-a-Lot, she eagerly anticipates the arrival of Nibbles’s
prize tan offspring. When Nibbles delivers, Judy is devastated. Nibbles has produced 2 brown bunnies, 2
white bunnies, and 0 tan bunnies.
9. (0. 5 point) What is dominance pattern of the coat color trait?
10. (0.5 point) Draw the Punnett square of a cross between Nibbles and Sir Hops-a-Lot
11. (0. 5 point) What were the chances of Nibbles producing zero tan bunnies?
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Questions 12 and 13 refer to the following scenario. Red – Green Color blindness is a sex linked
recessive trait. It affects males more frequently than females. Todd is Red – Green Color blind and Amy
has normal vision. Both of Todd’s parents have normal vision. Todd and Amy have two sons, Ryan and
Yovani. Yovani has normal vision but Ryan is Red – Green color blind.
12. (0.5 point) What are Amy and Todd’s genotypes?
Amy
Todd
13. (0.5 point) Did Ryan get the allele for Red – Green color blindness from Todd or Amy?
Label the following two scenarios as multifactorial or polygenic.
14. (0.5 point) Celiac disease is a disorder in which the immune system attacks gluten, a protein in
wheat, destroying intestinal villi in the process. The disease is characterized weight loss, fatigue,
malnourishment in those who eat wheat.
Malinda and Jami are identical twins who both have the DQ2 allele of the HLA-DQ gene,
a dominant allele which strongly predisposes one to Celiac disease. Malinda has spent a
year abroad in Italy, while Jami has been living at home with her parents. Malinda is
underweight and anemic while Jami is healthy. What might account for the difference
in phenotype between the two girls?
15. (0.5 point) Neil and Julio are fraternal (non-identical)
twins. They are homozygous for the same allele of the
HERC2 gene, which is involved in eye color. Neil has dark
brown eyes while Julio have light hazel eyes. Given that
eye color is not significantly affected by the
environment, what might account for the difference in
eye color?
16. (0.5 point) Place “crossing over” and “independent
assortment” next to the cell to the right for which it is
relevant.
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Complete the diagram below and be sure to follow any instructions and answer all questions.
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