R rr Rr RR
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: 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?
Possibilities:
- R
- rr
- Rr
- RR

Rr