Question

Examine the following scenario to answer the next set of questions. (Hint: I suggest you draw the crosses described in this scenario, then answer the questions based on your work). Imagine you did a cross between a true breeding homozygous white flowered pea plant and a true breeding homozygous purple flowered pea plant. All the offspring had purple flowers. You then allowed these offspring to self-fertilize. When you counted the offspring resulting from this second cross, you noticed about 3 purple flowered plants to every one white flowered plant. Use the letter “P” to symbolize the flower color gene. What are the genotypes of the original parents in this scenario? Pp; Pp PP; pp pp; pp PP; Pp

Answer 1

Answer:

The genotype of the original parents is  pp PP

Explanation:

Let “P” represents the purple color allele of the flower of pea plant

and “p” represents the white color allele of the flower of pea plant

Genotype of  homozygous purple flowered pea plant is represented by "PP"

Genotype of  homozygous white flowered pea plant is represented by "pp"

a) First generation cross between a homozygous purple flowered pea plant and a homozygous white flowered pea plant

P P

p Pp Pp

p Pp Pp

All the offspring are heterozygous purple flowered pea plants

b) In second generation cross is taking place between two heterozygous purple flowered pea plants with genotype "Pp"

P p

P PP Pp

p Pp pp

Out of four offspring , one is white while rest three are purple flowered pea plant.

Hence, the genotype of the original parents is  pp PP