What is the probability that a seed from a parent plant of genotype Rr will carry the r gene?

The probability that a seed from a parent plant with the genotype Rr will carry the r gene can be determined using a simple Punnett square. In this case, there are two possible alleles from the Rr parent: R and r. Therefore, the probability of a seed carrying the r gene is 50%, as there are two equally likely outcomes (R or r) when the gametes combine.