Punnett Square

The following questions will require you to work on a Punnett Square problem on your own. A pencil and paper may be necessary. Refer to Figure 8.12 in your textbook for examples. (page. 152)

Scenario 1: 

In corn plants, the allele for green kernels (G) is dominant over clear kernels (g). A homozygous dominant plant is crossed with a homozygous recessive plant.

1. What is the genotypic ratio of the offspring in Scenario 1?

a). 50% GG, 50% gg b.) 100% Gg c.) 25% GG, 50% Gg, 25% gg d.) 100% green

2. What is the phenotypic ratio of the offspring in Scenario 1?

a.) 50% green, 50% yellow. b.) 100% light green. c.) 25% GG, 50% Gg, 25% gg d.) 100% green

3. All the offspring of the cross in Scenario 1 will be _____.

a.) Homozygous dominant b.) Heterozygous dominant c.) Heterozygous d.) Recessive

Scenario 2: 

Green seeds are dominant over yellow seeds in pea plants. Cross a heterozygous (green seeded) plant with a yellow seeded plant.

1. What is the genotypic ratio of the offspring in Scenario 2?

a.) 75% yellow, 25% green b.) 75% Gg, 25% gg c.) 50% Gg, 50% gg d.) 35% green, 65% yellow

2. What is the phenotypic ratio of the offspring in Scenario 2?

a.) 50% green, 50% yellow b.) 75% Gg, 25% gg c.) 25% green, 75% yellow d.) 35% green, 65% yellow

The phenotypes of F1 offsprings are: Gg is green , and gg as yellow, thus again 1:1

3. The yellow-seeded offspring from the cross in Scenario 2 is __ ___.

a.) Homozygous dominant b.) Dominant c.) Homozygous recessive d.) Heterozygous