In a certain plant species, red flower color (R) is completely dominant over white flower color (r). If a heterozygous red-flowered plant is crossed with a homozygous white-flowered plant, calculate the expected phenotypic and genotypic frequencies of the offspring. Show all steps of the cross using a Punnett square.

Q: In a certain plant species, red flower color (R) is completely dominant over white flower color (r). If a heterozygous red-flowered plant is crossed with a homozygous white-flowered plant, calculate the expected phenotypic and genotypic frequencies of the offspring. Show all steps of the cross using a Punnett square.

Step-by-Step Problem Working and Calculation Identify the Genotypes of the Parents: Heterozygous red-flowered plant: Since it is heterozygous and red is dominant, its genotype must be Rr. Homozygous white-flowered plant: Since it is homozygous recessive (white is recessive to red), its genotype must be rr. Determine the Possible Gametes: Parent 1 (Rr) produces two types of gametes: R and r (in equal proportions of 50% each). Parent 2 (rr) produces only one type of gamete: r (100%). Construct the Punnett Square: | Gametes | R (50%) | r (50%) | |---|---|---| | r (100%) | Rr (Red) | rr (White) | Calculate Genotypic and Phenotypic Frequencies: Genotypes of Offspring: 50% or 1/2 Rr (Heterozygous red) 50% or 1/2 rr (Homozygous white) Genotypic Ratio: 1 Rr : 1 rr (or 1:1) Phenotypes of Offspring: 50% or 1/2 Red flowers 50% or 1/2 White flowers Phenotypic Ratio: 1 Red : 1 White (or 1:1) Conclusion: The expected offspring will show a 1:1 ratio for both genotype and phenotype.

Question

Accepted Answer

Step-by-Step Problem Working and Calculation

1. Identify the Genotypes of the Parents:

Heterozygous red-flowered plant: Since it is heterozygous and red is dominant, its genotype must be Rr.
Homozygous white-flowered plant: Since it is homozygous recessive (white is recessive to red), its genotype must be rr.

2. Determine the Possible Gametes:

Parent 1 (Rr) produces two types of gametes: R and r (in equal proportions of 50% each).
Parent 2 (rr) produces only one type of gamete: r (100%).

3. Construct the Punnett Square:

Gametes	R (50%)	r (50%)
r (100%)	Rr (Red)	rr (White)

4. Calculate Genotypic and Phenotypic Frequencies:

Genotypes of Offspring:
- 50% or 1/2 Rr (Heterozygous red)
- 50% or 1/2 rr (Homozygous white)
- Genotypic Ratio: 1 Rr : 1 rr (or 1:1)
Phenotypes of Offspring:
- 50% or 1/2 Red flowers
- 50% or 1/2 White flowers
- Phenotypic Ratio: 1 Red : 1 White (or 1:1)

Conclusion: The expected offspring will show a 1:1 ratio for both genotype and phenotype.