DAT Destroyer Biology Question 185

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

mkhan27

Full Member
10+ Year Member
Joined
Mar 19, 2011
Messages
331
Reaction score
81
A dihybrid cross was done between tall round peas. Tall is dominant to short and round is dominant to wrinkled. What fraction of the offspring will be short and wrinkled.

a) 1/16
b) 3/16
c) 6/16
d) 9/16
e) None of these.

Answer is A. I get how they got it based on the 9:3:3:1 ratio for these types of crosses, but.........am I overthinking here? The question says a dihybrid cross was done between tall round peas, but it doesn't say that it was a heterozygous dihybrid cross (i.e. TtRr). Tall round can also mean TTRR or TtRR or TTRr. My question is: Is a dihybrid cross by default with a TtRr x TtRr (unless they specify something like "A homozygous dominant tall and heterozygous wrinkled pea is crossed with a heterozygous tall and heterozygous round pea")

Members don't see this ad.
 
Its a "dihybrid", which implies heterozygous. If you hear dihybrid cross, i would assume its heterozygous and us 9331.
 
Top