Question

Item 1 is a combination of Upper R y and Upper R Upper Y. Item 2 is a combination of r y and Upper R y. Item 3 is Identify the genotype for each numbered item.
1.
2.
3.

the row label of a genotype of Upper R r Upper Y y with a column label of Upper R Upper Y. Item 4 is is a combination of r Upper Y and item 3.

Answer 1

I need one quick clarification to be sure I answer what you want: can you confirm the parents/gametes and which symbols are row vs column labels? (Uppercase = dominant allele, lowercase = recessive, R and Y are two genes — correct?)

Based on what you already wrote I can give the genotypes for the combinations you explicitly named:

- Item 1: Upper R y combined with Upper R Upper Y
- Gametes: Ry + RY
- Offspring genotype: R R Y y (RR Yy)

- Item 2: r y combined with Upper R y
- Gametes: ry + Ry
- Offspring genotype: R r y y (Rr yy)

For item 3 and 4 I need to know which two gametes are being combined for item 3 (you didn’t list them). If what you meant by “the row label of a genotype of Upper R r Upper Y y with a column label of Upper R Upper Y” is that one parent is RrYy (so its gametes are RY, Ry, rY, ry) and the other parent’s gamete (column) is RY, then the four possible offspring from each row gamete combined with RY are:

- RY × RY → RRYY
- Ry × RY → RRYy
- rY × RY → RrYY
- ry × RY → RrYy

So under that interpretation item 3 could be RrYY (if item 3 = rY × RY) and then item 4 (you said “Item 4 is a combination of rY and item 3”) would correspond to rY × RY → RrYY (same as the third bullet).

Tell me which gametes correspond to items 3 and 4 (or paste the Punnett square) and I’ll fill in the exact genotypes.