Question

in some plants, red flowers are dominant (r) and white flowers are recessive (r). two plants are crossed and the offspring have a possibility of ¾ red flowers and ¼ white flowers. which punnett square shows the cross and its offspring?

Explanation:

Step1: Recall Mendelian genetics ratios

In a monohybrid cross between two heterozygous individuals (Rr x Rr), the phenotypic ratio of the offspring is 3:1 (3 red - dominant phenotype to 1 white - recessive phenotype).

Step2: Analyze Punnett - square for Rr x Rr

When we set up a Punnett - square for Rr x Rr, the possible gametes from each parent are R and r. The combinations in the Punnett - square are RR:Rr:Rr:rr. The genotypes RR and Rr result in red flowers (dominant phenotype) and rr results in white flowers (recessive phenotype). So the probability of red flowers is $\frac{3}{4}$ and of white flowers is $\frac{1}{4}$.

Answer:

The Punnett - square with parents Rr and Rr (where one parent has gametes R and r along the top and the other has gametes R and r along the side, resulting in genotypes RR, Rr, Rr, rr in the 4 - box square) shows the cross and its offspring. The last option (with parents Rr and Rr) is correct.