How Mendel's Rules Explain Eye Color Inheritance

What color eyes will the offspring have if a true-breeding green-eyed male produces offspring with a true-breeding blue-eyed female?

1) Green
2) Blue

Answer:

A true-breeding green-eyed male and a true-breeding blue-eyed female will produce all green-eyed offspring due to the dominant nature of the green eye gene.

When a true-breeding green-eyed male, carrying two dominant genes (GG), produces offspring with a true-breeding blue-eyed female, carrying two recessive genes (bb), all the F1 generation offspring will inherit one dominant gene (G) and one recessive gene (b) from their parents. This means all the offspring will have green eyes, following Mendel's Law of Segregation which suggests that every individual has a pair of alleles for a certain trait and they segregate or separate during the formation of gametes.

However, if the F1 generation offspring breed among themselves or a test cross is performed, they can produce F2 generation offspring. The possibilities include 25% having two dominant genes (GG, green eyes), 50% having one dominant and one recessive gene (Gb, also green eyes due to dominance), and 25% having two recessive genes (bb, blue eyes). This distribution of traits in offspring is typically presented through a Punnett square and demonstrates Mendel's rules of inheritance.

So, despite the initial green-eyed offspring in the F1 generation, the blue-eyed trait will only reappear in the F2 generation at a ratio of 1:3, showcasing the genetic principles put forth by Gregor Mendel.