Question

"Mendel knew that the allele for smooth (R) seeds was dominant over the allele for wrinkled (r) seeds. If this cross was Rr × rr, what numbers would fill the middle column"

Answer 1

Rr and rr in the ratio of 1:1

Explanation:

If allele for smooth seed is Dominant over the allele for wrinkled seeds, and they are crossed 50 per-cent of the progeny will be heterozygous dominant  and 50 per-cent will be homozygous recessive.

Rr  X  rr

Rr Rr rr rr  F1 generation.

     r      r

R    rR   rr

r     Rr   rr

From Punnet square it will be 50 per-cent  chance each of rr and Rr.

Answer 2

Dominant traits are the traits that show both in phenotype as well as the genotype in the organism, while the recessive allele is present on the gene but in the presence of dominant trait get masked.

In the above case trait for seed shape is taken:

• Dominant trait= smooth seeds (R)

• Recessive trait= wrinkled seeds (r)

To see the cross between the rr and Rr see the attached image below:

• Smooth seed is a dominant trait while the wrinkled seed is a recessive trait.

• When Rr is crossed with rr then 50% of the offspring will be heterozygous dominant while the other 50% will be purebred recessive.

Therefore, from the Punnett square, 50% of the progeny will be heterozygous dominant while the other 50% will be purebred recessive.

To learn more about dominant and recessive traits follow the given link:

https://brainly.com/question/13050360