Question 1: D
To solve for Punnett squares, take the letter from the corresponding row and the letter from the corresponding column and write both in the corresponding box.
For instance, there is a capital T in the left column and a capital T in the top row. In the top - left box, "TT" would be written.
You can do this for the rest of the boxes to receive "Tt" for the top - right box, "Tt" for the bottom - left box, and "tt" for the bottom - right box.
The correct choice is D.
Question 2: E
This question uses the same Punnett square as the last.
The last one had combinations of TT, Tt, Tt, and tt - so 25% of the offspring have the genotype tt, meaning short.
Question 3: L
The genotype of an offspring is its gene combination - so the TT, Tt, and tt I was describing earlier. The phenotype is its appearance - in this case, purple or white.
Box 2 has a purple flower with a genotype of Bb, so the correct choice is L.
Question 4: S and T
Heterozygous genotypes can also be called "mixed" genotypes. They have both genes. In this case, that means Bb (instead of the homozygous genotypes of bb and BB).
Box 2 and 3 have the genotype of Bb, so the correct choices are S and T.