Question

One character in peas that Mendel studied was yellow versus green seeds. A cross between a homozygous yellow line (YY) and a homozygous green line (yy) will result in F1 plants that are heterozygous (Yy) for this trait and produce yellow seeds. When an F1 plant undergoes meiosis, what gamete types will it produce, and in what proportions? Use your understanding of Mendel's law (or principle) of segregation to label each gamete possibility as "correct" or "incorrect."

(a) 3/4 Y 1/4y

(b) 1/2Y 1/2y

(c) 1/2YY 1/2yy

(d) 1/2Yy 1/2Yy

(e) 3/4y 1/4Y

(f) 1/2y 1/2y

Answer 1

(b) 1/2Y 1/2y: Correct

Rest options are incorrect.

Step-by-step explanation:

According to Mendel's law of segregation, the dominant and recessive alleles of a gene present together in a heterozygote do not get mixed and are segregated during gamete formation. Gametes are always pure and carry one allele of each gene. A gamete from a plant with "Yy" genotype cannot have two copies of either of the alleles.

The alleles of a gene are present on homologous chromosomes. Separation of homologous chromosomes carrying Y and y alleles each would result in the segregation of these alleles during gamete formation. The resultant 50% gametes would have a "Y" allele and the rest 50% would have a "y" allele.