Download Genetics Problems

Written Assignment 3, Summer, 2005: Genetics Problems
Dr. Dennis L. Frisby
Name ____________________
MULTIPLE CHOICE. Circle the one alternative that best completes the statement
or answers the question. On a SEPARATE sheet of paper, you MUST SHOW
YOUR WORK for each problem. Show Punnent squares, calculations, etc. for
each. Write neatly and clearly. If I cannot read or follow what you have written,
the answer will be counted wrong, regardless of whether you circle the correct
alternative.
1. In lilies, white flowers (W) are dominant to purple flowers (w). If two plants that
are heterozygous for flower color are mated, the offspring might have which
genotype?
A) Ww
B) Ww
C) WW
D) All of the above
E) None of the above
2. Flower color in snapdragons is a trait showing incomplete dominance. Therefore,
the flowers of a snapdragon plant that is the offspring between a plant with red
flowers and one with white flowers would be
A) pink.
B) some red and some white.
C) red.
D) red with white spots.
E) white.
3. In lilies, white flowers (W) are dominant to purple flowers (w). If two plants that
are heterozygous for flower color are mated, the offspring would be expected to
show which phenotypic ratio?
A) 1:1
B) 3:1
C) 1:2:1
D) 9:3:3:1
E) None of the above
4. In pea plants, the smooth seed allele is dominant to the wrinkled seed allele. The
F1 generation resulting from a mating between a true-breeding pea plant bearing
smooth seeds and one bearing wrinkled seeds would show which phenotype?
A) all wrinkled seeds
B) ¾ wrinkled and ¼ smooth
C) ¼ wrinkled and ¾ smooth
D) All smooth seeds
E) ½ smooth seeds and ½ wrinkled seeds
5. In tomatoes, yellow fruit color (y allele) is recessive to red fruit color (Y allele)
and pear shape (p allele) is recessive to round fruit shape (P allele). If a
homozygous yellow pear tomato plant is crossed with a homozygous red round
tomato what is the phenotype of the F1 progeny?
A) red round
B) red pear
C) yellow round
D) yellow pear
E) orange oval
6. The observable characteristics of an organism that result from the expression os
gene’s is the organism’s
A) heterotype.
B) phenocopy. C) phenotype. D) genotype. E) karyotype.
7. In humans, brown eye color (B) is dominant to blue eyes (b). Two parents with
brown eyes have a large family of 24 children. 18 of the children have brown
eyes, and 6 of them have blue eyes. This indicates that the parent’s genotypes are
A) Bb and Bb.
B) BB and bb.
C) bb and bb.
D) BB and Bb.
E) Bb and bb.
8. One of the blue eyed girls from the previous question marries a man with brown
eyes. What phenotypes for eye color can their children have?
A) Blue.
B) Brown.
C) Green
D) A and B are correct
E) B and C are correct
9. A man with blood type A and a woman with blood type B could never produce a
child with blood type
A) O.
B) AB.
C) B.
D) A.
E) None of the above.
10. A couple who are both carriers of the gene for cystic fibrosis have two children
who have cystic fibrosis. What is the probability that their next child will be
phenotypically normal?
A) 0%
B) 100%
C) 75%
D) 25%
E)50%