Question

1. Cross a homozygous purple Plant (PP) with a homozygous white plans (PP). This is called the P1 cross, and it will produce offspring called the F1 generation. You are given that purple color is dominant to white in this species.

a) What is the genotype of the purple plant?

b) What gametes can the purple plant make?

c) What is the genotype of the white plant?

d) What gametes can the white plant make?

e) Create a Punnett Square explaining this.

f) What is the genotypic Ratio?

g) What is the phenotypic ratio?

2. Cross a homozygous tall yellow seeded plant with a homozygous short green seeded plant. This is called the P1 cross, and it will produce offspring called the F1 generation. Tallness is dominant to shortness, so use a capital T to represent the tallness allele and lower case t to represent the shortness allele. Yellow seeds are dominant to green sees, so use a capital Y to represent the yellow seed allele and a lower case y to represent the green seed allele.

a) What is the genotype of the tall plant?

b) What gametes can the tall plant make?

c) What is the genotype of the short plant?

d) What gametes can the short plant make?

e) Create a punnett square explaining this

f) What is the genotypic ratio of the F1 plants?

g) What is the phenotypic ration of the F1 plants?

Answer 1

a) What is the genotype of the purple plant? – Homozygous dominant or heterozygous (PP or Pp)

b) What gametes can the purple plant make? – Its gametes are, “P and p”

c) What is the genotype of the white plant? – Homozygous recessive (pp)

d) What gametes can the white plant make? – Its gametes are, “p”

So, the genotype of “F1” is, “Pp”

Cross between Pp and Pp (F1 cross) will have the progeny with the following genotypes.

Pp*Pp -à PP (1/4, purple), Pp (1/2, purple), pp (1/4, white)

e) Create a Punnett Square explaining this.

	P	p
P	PP (purple)	Pp (purple)
p	Pp (purple)	pp (white)

f) What is the genotypic Ratio? 1:2:1 (PP:Pp:pp)

g) What is the phenotypic ratio? 3:1 (purple:white)