If round seed (RR) was dominant over wrinkled seed (rr) in a monohybrid cross, and yellow pod (YY) was dominant over brown pod (yy), what should be the starting genotype of parents in a dihybrid cross?
A. RRrr and YYyy
B. RRYY and rryy
C. RRyy and YYrr
D. RrYy and RrYy
The question was posed to me during a job interview.
The above asked question is from Inheritance of Two Genes-1 in chapter Principles of Inheritance and Variation of Biology – Class 12
Right answer is B. RRYY and rryy
The explanation: The dihybrid cross is used to the inheritance pattern of two contrasting characters. Hence, they should be true-breeding. One for both dominant traits and the other for both recessive traits.