T (tall) is dominant over t (short) . G (green) is dominant over g (yellow)
Cross a short, yellow plant with a plant that is heterozygous for both traits
What fraction of the offspring
will be short and green?

1/4

Explanation:

In order for a plant to be short and yellow, it needs to have hοmοzygous lowercase letters for height and color.

If the plant had one capital letter for either height, color, or both, this would dominate the recessive gene and would not allow the plant to exhibit the recessive trait.

The short, yellow plant has a genotype of:

The plant that is heterozygous for both traits means that its genotype has both the dominant (capital) and recessive (lowercase) letters.

The heterozygous plant has a genotype of:

We can use a dihybrid crossing of alleles in a 4x4 Punnett square. To figure out which four pairs of alleles to use for crossing, we can FOIL the genotypes of the two plants getting crossed.

Use these pairs of alleles to cross in the Punnett square. To see which offspring will be short and green, we need to look at the pairs of alleles for the height and color traits separately.

Short plants must have the genotype of tt.

Green plants can have the genotype of GG or Gg.

Look at the Punnett square to see which genotypes are hοmοzygous for the short trait and either hοmοzygous or heterozygous for the green trait.

We can see that the third row of genotypes consist of ttGg, which corresponds to the short and green phenotypes.

Therefore, 1/4 of the offspring will be short and green.