In tomato's, red fruit (R) is dominant over yellow fruit (r). What is the probability that an offspring of plants that are heterozygous (Rr) produce plants with the homozygous recessive (rr) genotype?

1 out of 4

or

25%

Explanation:

First we draw a Punnett Square for this:

R r

R RR Rr

r Rr rr

So here we have the following genotypes possible for this cross:

RR = homozygous dominant

Rr = heterozygous dominant

rr = homozygous recessive

As you can see out of the four (4) possible outcomes, one (1) of them is rr. So the probability is 1 out of 4 chances or 25%.