Question

A botanist crosses two pink-flowered plants. The cross involves alleles that were not clearly dominant or recessive and could make red, pink, and white-flowered plants. If four plants are produced from the cross, what is the expected number of white-flowered plants?

Answer 1

Answer:

1

Explanation:

According to the information in this question, a gene coding for flower color in a plant is involved. The allele for red color (R) is incompletely dominant over the allele for white color (r) to form an intermediate phenotype/color i.e. Pink that is heterozygous (Rr) for the gene.

If two pink plants are crossed i.e. Rr × Rr, each parent will produce R and r gametes. Using these gametes in a punnet square (see attached image), the following offsprings will result: RR, Rr, Rr, and rr.

Out of these four offsprings;

1 RR is red : 2 Rr is pink: 1 rr is white

Hence, If four plants are produced from this cross, according to this question, the expected number of white-flowered plants will be 1 out of 4.