Answer:
D.) If the homozygous tall plant (TT) crosses with a homozygous short plant (tt), then all the F1 plants become heterozygous tall plants (Tt).
Explanation:
Homozygous indicates that the alleles in the genotype are the same. Therefore, the genotype for homozygous tall plants is (TT) and the genotype for homozygous short plants is (tt).
After performing a cross, we know that all of the children will have the heterozygous genotype (Tt).
Explanation:
As you can see in the picture below, this is a dihybrid cross with a twist.
We can accomplish that mutually parentages are heterozygotes for both characters because the genotypes are
9 unicorns with curly tails (shown in green)
3 with straight tails (shown in red)
3 curly tales trait carriers with no tail (shown in dark blue)
1 straight tail trait carriers with no tail ( shown in light blue)
If this was an ordinary case of the dihybrid cross, we would get a 9:3:3:1 phenotype ratio.
However, since the first trait, the presence of the tail, is affecting the other trait, the trait texture, the ratio is altered.
of the offspring (genotypes tt C_ and tt SS) has no tail, therefore we cannot observe the texture of the tail (some of the tailless individuals have Curly alleles -blue squares marked with green, some of them have Straight alleles -blue square marked with red ).
Therefore, the altered ratio is curly tails,
straight tales,
tailless