Question

homework - complete dominance inheritance pattern
the ability to roll the tongue in humans is coded by the dominant allele r. the inability to roll the tongue is coded by the recessive allele r. a man with an rr allele combination for the trait produces a zygote with a woman with an rr allele combination for the trait. which allele combination could occur in the zygote?
rrrr
rr
rr
rr

Explanation:

In genetics, when a parent with genotype \(RR\) (homozygous dominant) and a parent with genotype \(rr\) (homozygous recessive) produce offspring:

• The \(RR\) parent can only contribute an \(R\) allele.
• The \(rr\) parent can only contribute an \(r\) allele.
• By the rules of Mendelian inheritance (specifically the law of segregation), each parent donates one allele to the zygote. So the combination in the zygote must be \(Rr\).

Answer:

C. \(Rr\)