Question

In peas, the trait for tall plants is dominant (T) and the trait for short plants is recessive (t). The trait for yellow seed color is dominant (Y) and the trait for green seed color is recessive (y). A cross between two plants results in 296 tall yellow plants and 104 tall green plants. Which of the following are most likely to be the genotypes of the parents?
a. TyYY x Ttyyb. TTYy x TTYyc. TTyy x TTYyd. TtYy x TtYy

Answer 1

Answer:

TTYy x TTYy and  TtYy x TtYy

Explanation:

Cross between two the two plants yielded yellow and green plant in the ratio 296:104.

296:104 is approximately equal to 3:1.

According to Mendelian law, 3:1 ratio of dominant to recessive phenotype results from a cross involving two heterozygous individual.

Taking the seed colour into consideration, a cross between two heterozygous individual will be:

Yy   x   Yy = YY, 2Yy and yy

Ration of yellow to green = 3:1

Hence, option b and option d are most likely to be the genotypes of the parent because both shows the genotype of seed colour in heterozygous conditions.