Question

Yellow squash Y is dominant over white squash y. A cross between YY and yy occurs. What are the phenotypic percentages?

Answer 1

By crossing a yellow squash (YY) with a white squash (yy) , the phenotypic percentage of the offspring is 100% yellow squash (Yy).

Step-by-step explanation:

The crossing of two pure lines -with identical alleles for a trait- dominant and recessive produces a hybrid or heterozygous offspring, with different alleles for that trait.

In this case, the yellow squash is homozygous dominant, while the white squash is recessive, obviously homozygous.

YY X yy

Alleles Y Y

y Yy Yy

y Yy Yy

All the offspring will have a Yy genotype and a single yellow squash phenotype for 100% of them.