Answer:
D. Tt with Tt
Explanation:
In the given question, the student wants to study the stem length in the plants which are controlled by the T (dominant) and t (recessive) alleles.
To study the monohybrid cross for the stem length, the student must cross the heterozygous forms of the gene for the trait as it will produce the mixture of variables of height.
cross- Tt x Tt
T t
T TT Tt
t Tt tt
1. Genotype TT - tall height
2. Genotype Tt- tall height
3. Genotype tt- small height
Thus, Option-D is correct answer.
