Question

in pea plants, height is determined by an allele for tallness (t) that is dominant over an allele for shortness (t). what is the probability that a gamete, selected at random, would carry the short allele (t) in a cross of heterozygous tall pea plants?
a. 1/8
b. 1/4
c. 1/2
d. 3/4

Explanation:

Step1: Identify parent genotypes

Heterozygous tall plants: $Tt \times Tt$

Step2: List gamete combinations

Offspring genotypes: $TT, Tt, Tt, tt$

Step3: Count allele-carrying genotypes

Genotypes with $t$: $Tt, Tt, tt$ (3 total)

Step4: Calculate probability

$\text{Probability} = \frac{\text{Number of genotypes with } t}{\text{Total genotypes}} = \frac{3}{4}$

Answer:

D. 3/4