Question

Question 2b)

You are studying a flowering plant that produces remarkable bright green flowers in its wild type.

Your colleagues have discovered two new mutant lines of this plant.

One new line breeds true for a yellow flower color. Another new line breeds true for a blue flower color.

Your group does the following crosses and makes these observations:

yellow X green ⇒ F₁ is all green ⇒ F₂ 75% green and 25% yellow

blue X green ⇒   F₁ is all green ⇒ F₂ 75% green and 25% blue

yellow X blue ⇒ F₁ is all green ⇒ F₂ ???

The bright green flower color is a result of the mixture of yellow and blue pigment, and the intermediate products in the pigment biosynthetic pathways are colorless.

What phenotypic ratio would you predict in the F₂ of the last cross? In other words, what do you expect to see for flower color where it is marked "???" above?

	a.	9 green : 4 blue : 3 yellow
	b.	12 green : 3 blue : 1 white (colorless)
	c.	9 green : 7 white (colorless)
	d.	3 green : 1 white (colorless)
	e.	9 green : 3 blue : 3 yellow : 1 white (colorless)

Question 2c)

A pure-breeding white pig is crossed to a pure-breeding black pig. All of the F₁ are white.

However, the F₂ generation from a self cross of F₁ yields 9/16 white pigs, 1/16 black pigs, and 6/16 pigs with a new color: sandy.

When an individual white pig (named the alpha parent) is crossed to an individual sandy pig (called the beta parent), the progeny that results are four sandy piglets, three white piglets, and one black piglet.

What are the most likely genotypes of the alpha and beta parents?

	a.	A/A; B/b  and  A/a; B/b
	b.	A/a; B/b  and  a/a; B/B
	c.	A/a; b/b and A/a; B/b
	d.	A/A; b/b  and  A/a; B/b
	e.	A/A; B/B  and  A/a; B/b

Answer 1

Ans.2b ...9:3:3:1 because of that individual dominant gene gives yellow or blue flower also while both of their recessive gives colourless and both dominnat gives the intermediate or mix composition of both which is of green colour.

Ans.2c.A/a;B/b and a/a;B/B