Question

Imagine that you are performing a cross involving seed color in garden pea plants. What traits would you expect to observe in the F1 offspring if you cross true-breeding parents with green seeds and yellow seeds? Yellow seed color is dominant over green.

a) All green seeds
b) All yellow seeds
c) All intermediate seeds
d) All heterozygous seeds

Answer 1

Crossing true-breeding pea plants with green and yellow seeds will result in F1 offspring with yellow seeds due to yellow being the dominant trait. All F1 offspring will have the heterozygous genotype Yy and express the dominant yellow seed phenotype.

Step-by-step explanation:

F1 Offspring Seed Color in Pea Plants

When crossing two true-breeding garden pea plants, one with green seeds and the other with yellow seeds, given that yellow seed color is dominant over green, the F1 (first filial) generation would be expected to show one specific phenotype in relation to seed color. Since yellow is dominant (Y) and green is recessive (y), and each parent contributes one allele, all the F1 offspring will have the genotype Yy. Therefore, we would expect to see all offspring with yellow seeds since the dominant allele masks the expression of the recessive allele in a heterozygous genotype.

The F1 offspring will not show an intermediate color nor will they show a mix of green and yellow seeds. Instead, they will all display the dominant yellow seed color. A Punnett square analysis of this cross would confirm that all the F1 offspring will be heterozygous (Yy) with a yellow phenotype.