Download In snapdragons, red flower color (CR) is incompletely dominant to

1. In snapdragons, red flower color (CR) is incompletely dominant to white flower color (Cw) ; the
heterozygote has pink flowers. Also, normal broad leaves (LB) are incompletely dominant to
narrow, grasslike leave (LN); the heterozygote has an intermediate leaf breadth. If a red-flowered,
narrow-leafed snapdragon is crossed with a white-flowered, broad-leafed one, what will be the
phenotypes of the F1 and F2 generations, and what will be the frequencies of the different classes?
2. In snapdragons, red flower color (CR) is incompletely dominant to white flower color (Cw) ; the
heterozygote has pink flowers. Normal-shape flowers (N) are completely dominant to peloricshaped ones (n); and tallness (T) is completely dominant to dwarfness (t). Three gene pairs
segregate independently. If a homozygous red, tall, normal-flowered plant is crossed with a
homozygous white, dwarf, peloric-flowered one, what proportion of the F2 plants will resemble
the F1 plants in appearance?
3. In rabbits, C = agouti coat color, cch – chinchilla, ch = Himalayan, and c = albino. The four alleles
constitute a multiple allelic series. The agouti C is dominant to the other three alleles, c is
recessive to the other three alleles, and chinchilla is dominant to Himalayan. Determine the
phenotypes of progeny from the following crosses:
a. C/C x c/c
b. C/cch x C/c
c. C/c x C/c
d. C/ ch x ch/c
e. C/ ch x c/c
4. In humans, the three alleles IA, IB, and i constitute a multiple allelic series that determines the ABO
blood group system, as described in this chapter. For the following problems, state whether the
child mentioned can be produced, and explain your answer:
a. An O child by a mating of two A individuals
b. An O child by an A and a B mating
c. An AB child by an A and O mating
d. An O child by an AB and an A mating
e. An A child by an AB and a B mating
5. A woman of blood group AB marries a man of blood group A whose father was of group O. What
is the probability that …
a. their two children will both be of group A?
b. one child will be of group B, the other of group O?
c. the first child will be a son of group AB and the second child a son of group B?
6. In guinea pigs, short hair (L) is dominant to long hair (l), and the heterozygous conditions of
yellow coat (Cy) and white coat (Cw) give cream coat. A short-haired, cream guinea pig is bred to
a long-haired, white guinea pig, and a long-haired, cream baby guinea pig is produced. When the
baby grows up, it is bred back the short-haired, cream parent. What phenotypic classes, and in
what proportions, are expected among the offspring?
7. The shape of radishes may be long (SL/SL), oval (SL/Ss), or round (Ss/Ss), and the color of
radishes may be red (CR/CR), pink (CR/CW), or white (CW/CW). If a long red radish plant is
crossed with a round, white plant, what will be the appearance of the F1 and F2 plants?
8. In peaches, fuzzy skin (F) is completely dominant to smooth (nectarine) skin (f), and the
heterozygous condition of oval glands at the base of the leaves (GO) and no glands (GN) gives
round glands. A homozygous fuzzy, no-gland peach variety is bred to a smooth, oval-gland
variety.
A. What will be the appearance of the F1 peaches?
B. What will be the appearance of the F2 peaches?
C. What will be the appearance of the offspring of a cross of the F1 peaches back to that
smooth, oval-glanded parent?
9. In sheep, white fleece (W) is dominant to black (w) and horned (H) is dominant to hornless (h). A
horned white ram is bred to the following four ewes and has one offspring by the first three and
two by the fourth: Ewe A is hornless and black; the offspring is a horned white female. Ewe B is
hornless and white; the offspring is a hornless black female. Ewe C is horned and black; the
offspring is a horned white female. Ewe D is hornless and white; the offspring are one hornless
black male and one horned white female. What are the genotypes of the five parents?
10. In sheep, white fleece (W) is dominant to black (w) and horned (H) is dominant to hornless (h). A
horned white ewe produces the following offspring: Of the males, ¼ are horned, white: ¼ are
horned, black; ¼ are hornless, white; and ¼ are hornless, black. Of the females, ½ are hornless
and black, and ½ are hornless and white. What are the genotypes of the parents?
11. In shorthorn cattle, the heterozygous condition of the alleles for red coat color (CR) and white coat
color (Cw) is a roan coat color. What progeny would result from the cross of a roan bull and a
a. roan cow.
b. red cow.
c. white cow.