1. White skin (W) is dominant over yellow skin (w) in chickens. Which of the following genotypes would result in a white-skinned chicken that could possibly have yellow-skinned offspring?
A. WW
B. Ww**
C. ww
2. Which of the following describes the genotype and phenotype of parents whose child will definitely have a recessive trait?
A. Both parents have a homozygous for the recessive allele and have that trait**
B. Both parents have a homozygous for the recessive allele but do not have that trait
C. Both parents have a heterozygous for the recessive allele and have that trait
D. Both parents have a heterozygous for the recessive allele but do not that that trait
3. A long-haired cat (recessive trait s) is crossed with a heterozygous short-haired cat (dominant trait S). Which percentage of their offspring will have long hair?
A. 100 percent
B. 50 percent**
C. 25 percent
D. 0 percent
4. In humans, having dimples is a dominant trait. If one parent has dimples and is homozygous for the trait, what is the probability any of his or her offspring will NOT have dimples?
A. 100 percent
B. 50 percent
C. 25 percent**
D. 0 percent
5. In humans, having more than 5 fingers or toes is dominant over having exactly 5 fingers or toes. Which of the following situations is most likely result in exactly half of a couple’s offspring having 6 digits and half of them having 5?
A. Both parents are homozygous for this trait**
B. Both parents are homozygous
C. One parent is heterozygous while the other is homozygous for this recessive trait
D. One parent is homozygous for the recessive trait while the other is homozygous for the dominant trait
CHECK!
22 answers
2. c
3. a
4. d
5. b
As a matter of fact, Jiskha does not have a biology expert now.
Homozygous means that animal has two of the same allele. To guarantee an offspring will have a recessive trait (in problem 2) both parents must be homozygous in the recessive allele (if not, the child could get the dominant gene). If both parents have two recessive genes, they will have the recessive trait. Thus for problem 2, A is correct. In fact, answers B and C cannot exist.
Ss - short hair
Ss - short hair
ss - long hair and
ss - long hair.
Half have long hair and half have short, so the answer is B.
1:b
2:a
3:b
4:c
5:a
1. b.
2. a.
3. b.
4. d.
5. c
1. B
2. A
3. B
4. D
5. C