In rabbits, gray hair (G) is dominant to white hair (g), and black eyes (B) are dominant to red eyes (b). These two traits are independent of each other. In other words, a female rabbit with the genotype GgBb may produce eggs with the alleles GB, Gb, gB, or gb. To predict the probability of these sorts of crosses, we will make a dihybrid Punnett Square.
GG = gray hair
BB=black eyes
Gg = gray hair
Bb=black eyes
gg = white hair
bb=red eyes
1.What are the phenotypes (descriptions) of rabbits that have the following
genotypes:
Ggbb ____________________ ggBB ________________________
ggbb ____________________ GgBb _________________________
2. A male rabbit with the genotype GGbb is crossed with a female rabbit with the genotype ggBb .
Determine the phenotypes and proportions in the offspring.
3.A tall, yellow-seeded pea plant heterozygous for height and seed color (TtYy) is crossed with a tall, green-seeded pea plant that is heterozygous for height but homozygous recessive for seed colour (Ttyy). If 80 offspring are produced, how many are expected to be tall and have yellow seeds?
Answers
Answer:
1. Genotypes:
Ggbb = Grey hair, Red eyes
ggBB = White hair, Black eyes
ggbb = White hair, Red eyes
GgBb = Grey hair, black eyes
2. Phenotypes and proportions
Grey hair, red-eyes - 8
Grey hair, black-eyes - 8
White hair, red-eyes - 0
White hair, black-eyes - 0
3. If 80 offspring are produced then,
80/16 X 6 = 5 X 6 = 30
Then 30 offspring are expected to be tall and have yellow seeds.
Explanation:
1. The four genotypes will be as follows
Ggbb = Grey hair, Red eyes
ggBB = White hair, Black eyes
ggbb = White hair, Red eyes
GgBb = Grey hair, black eyes
2. With the help of Punnet square it is determined that, the offsprings will be of two phenotypes in the following proportion
Grey hair, red-eyes - 8
Grey hair, black-eyes - 8
3. If a tall, yellow-seeded pea plant heterozygous for height and seed color (TtYy) is crossed with a tall, green-seeded pea plant that is heterozygous for height but homozygous recessive for seed colour (Ttyy),
Then according to the punnet square out of 16 offsprings , 6 offsprings will be tall and will have yellow seeds.
So for 80 offsprings,
= 80/16 X 6
= 5 X 6
= 30
Therefore, 30 offspring are expected to be tall and have yellow seeds .
Answer:
1. Genotypes:
Ggbb = Gray Hair, Red Eyes
ggBB = White hair, dark eyes
ggbb = White hair, Red eyes
GgBb = Gray hair, dark eyes
2. Phenotypes and metrics
Gray hair, red eyes - 8
Gray hair, dark eyes - 8
White hair, red eyes - 0
White hair, dark eyes - 0
3. When 80 interest is produced,
80/16 X 6 = 5 X 6 = 30
Then 30 seeds are expected to be longer and have yellow seeds.
Explanation:
1. The four types of genotype will be as follows
Ggbb = Gray Hair, Red Eyes
ggBB = White hair, Black eyes
ggbb = White hair, Red eyes
GgBb = Gray hair, dark eyes
2. With the help of Punnet square it is determined that the interest will be two phenotypes in the following section.
Gray hair, red eyes - 8
Gray hair, dark eyes - 8
3. When the tall, yellow heterozygous pea and seed (TtYy) plant is cut off from the tall, blue-seeded pea plant with heterozygous in length but homozygous recessive in seed color (Ttyy),
Then at the punnet square for 16 children, 6 offspring will be longer and have yellow seeds.
So with 80 descendants,
= 80/16 X 6
= 5 X 6
= 30
Therefore, 30 offspring are expected to be tall and have yellow seeds.
#SPJ2