Which letters can be used to model mendel’s cross of true-breeding tall plants with true-breeding short plants in a punnett square?

Ans.

Mendel performed various experiments on garden pea plants to study inheritance of characters. He studied different traits of pea plants, such as height of plants, color of flower, and sees shape. For plant height, Mendel used capital 'T' letter to denote allele for tall character, while he used small 't' letter to denote allele for dwarf character.  According to Mendel, the true-breeding or homogeneous. plants show both the same allele for a trait.  

Thus, the letters 'TT' and 'tt' can be used for Mendel's experiment that shows cross between true-breeding tall plants and short plants in a Punnett square, respectively.  

answer; both surfaces of the membrane are nonpermeable