I'm trying to construct a punett square on progeny from given information, and what i get does not match with what the parents should be. when i put Rt and Rt, and when i put Rt and rt, i can't put them together. i'm doing something wrong for sure. can you please explain in steps what to do?
Remember that a punnet square is always crossing two parents full genotypes - that means for every trait, you are crossing a minimum of 2 alleles for each parent. What you would be crossing here is Rrtt x Rrtt. You don't know if these genes are linked or not, so do two separate punnet squares, one for each trait:
tt x tt (this doesn't really need a punnet square - you already know the outcome - always tt)
Rr x Rr (the outcome of this cross should be RR, Rr, Rr, and rr)
It sounds like you tried to do a more complicated method of figuring out the gametes the parents would produce (each parent has a 50% chance of product a Rt gamete or an rt gamete) and then crossed those...but doing it that way is a lot more difficult because you would have to consider multiple probabilities (that parent 1 produced Rt and parent 2 produced Rt, that parent 1 produced Rt and parent 2 produced rt, that parent 1 produced rt and parent 2 produced rt, etc.). Don't use that method, figure out the individual crosses for each trait first - it's a lot simpler.
Also, I think trying to reverse construct a punnet square from progeny information is just a giant headache. Try to focus on the information given to you about the parents first to figure out the potential crosses that could have taken place, and then use a punnet square at the end to confirm your answer. Doing it the reverse way is unnecessary and convoluted.
