In a certain plant species, the allele for red flowers (R) is dominant to the allele for white flowers (r). What is the phenotype result of a cross between two groups of red-flowered plants, both of have all individuals that are heterozygous for the gene.

A.

1/4 red flowers; 3/4 white flowers

B.

all red flowers; no white flowers

C.

1/4 white flowers; 3/4 red flowers

D.

all white flowers; no red flowers

Question

Biology

Amira Zhang

15 April, 05:04

In a certain plant species, the allele for red flowers (R) is dominant to the allele for white flowers (r). What is the phenotype result of a cross between two groups of red-flowered plants, both of have all individuals that are heterozygous for the gene.

A.

1/4 red flowers; 3/4 white flowers

B.

all red flowers; no white flowers

C.

1/4 white flowers; 3/4 red flowers

D.

all white flowers; no red flowers

+4

Answers (1)

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Kaylyn · Answer 1

C. 1/4 white flowers, 3/4 red flowers

Since both flowers being crossed are heterozygous, their genotypes would be:

Rr

The cross would be: Rr x Rr = RR, Rr, Rr and rr will be the possible genotypes of resulting offspring.

Hence, as can be seen from the result, RR, Rr and Rr will all be red flowers, since red is the dominant phenotype and hence 75% or 3/4ths of offspring will be red. 25% or 1/4th of offspring will be white with the genotyoe of rr.