Question

part ii: monohybrid cross
instruction: using punnett square, find the phenotype and genotype of the possible offspring from the following cross:

1. trait: color of peas flower

dominant: purple color (p)
recessive: white color (p)
cross: pp x pp
phenotype: genotype: phenotypic ratio: genotypic ratio:

1. trait: eye shape

dominant: round eyes (r)
recessive: narrow eyes (r)
cross: rr x rr
phenotype: genotype: phenotypic ratio: genotypic ratio:

Explanation:

Step1: Set up Punnett square for Pp x Pp

For the cross Pp x Pp, the possible gametes from each parent are P and p. We set up a 2x2 Punnett - square.

	P	p
p	Pp	pp

Step2: Determine phenotypes and ratios

The dominant phenotype (purple) is shown by PP and Pp genotypes, and the recessive phenotype (white) is shown by pp. So, the phenotype is purple and white. The phenotypic ratio is 3 purple : 1 white ($\frac{3}{4}$ purple and $\frac{1}{4}$ white).

Step3: Determine genotypes and ratios

The genotypes are PP, Pp, and pp. The genotypic ratio is 1 PP : 2 Pp : 1 pp.

Step4: Set up Punnett square for Rr x rr

For the cross Rr x rr, the possible gametes from the Rr parent are R and r, and from the rr parent are r. We set up a 2x2 Punnett - square.

	R	r
r	Rr	rr

Step5: Determine phenotypes and ratios

The dominant phenotype (round eyes) is shown by Rr genotype, and the recessive phenotype (narrow eyes) is shown by rr. So, the phenotype is round eyes and narrow eyes. The phenotypic ratio is 1 round eyes : 1 narrow eyes ($\frac{1}{2}$ round eyes and $\frac{1}{2}$ narrow eyes).

Step6: Determine genotypes and ratios

The genotypes are Rr and rr. The genotypic ratio is 1 Rr : 1 rr.

Answer:

1. Phenotype: Purple, White; Phenotypic ratio: 3:1; Genotype: PP, Pp, pp; Genotypic ratio: 1:2:1
2. Phenotype: Round Eyes, Narrow Eyes; Phenotypic ratio: 1:1; Genotype: Rr, rr; Genotypic ratio: 1:1