In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent of offspring that will be tall if a heter
In pea plants, the allele for tall (T) is dominant to the allele for short (t). Which of the following is the percent of offspring that will be tall if a heterozygous plant (Tt) is crossed with a homozygous tall plant?
A. 100%<~~~ I think it's A
B. 75%
c. 50%
D. 25%
All the gametes from homozygous tall plants would be T and then from heterozygous plant would be T and t. If you make a punnett square then you will see that 100% of progeny is tall due to Tt genotype (50%) and TT genotype (50%) since T is dominant to t.
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To determine the percent of offspring that will be tall in this cross, you can use a Punnett square. A Punnett square is a grid that helps predict the possible genetic outcomes of a cross.
In this case, you are crossing a heterozygous plant (Tt) with a homozygous tall plant (TT). The homozygous tall plant has two dominant alleles for tallness (T), while the heterozygous plant has one dominant allele and one recessive allele (Tt).
To create a Punnett square, write the alleles for each parent above and to the side of the grid. For the homozygous tall plant (TT), write T on the top row and T on the side column. For the heterozygous plant (Tt), write T on the top row and t on the side column.
The Punnett square for this cross will look like this:
| T | T |
----|---|---|
T | TT | TT |
t | Tt | Tt |
The resulting genotypes in the offspring are TT (2 squares) and Tt (2 squares).
The TT genotype corresponds to tall plants because T is dominant over t. The Tt genotype also corresponds to tall plants because the presence of the dominant allele T masks the presence of the recessive allele t.
Therefore, 100% of the offspring will be tall. So, the correct answer is A.