Question

Two average height parents have several children, all about the same average height as their parents. Which set of parental genotypes could account for these data? (Mark all correct answers)

	a.	AABBCC x aabbcc
	b.	AABB x aabb
	c.	AABBccdd x aabbCCDD
	d.	AABBccdd x AABBccdd
	e.	AaBbCcDd x AaBbCcDd

If height in plants was controlled by three additive genes, A, B, and C, a cross of an intermediate plant with a genotype of AaBbCc with an intermediate plant with a genotype of AaBbCc, would produce what ratios of heights in the offspring?

	1.	1:4:6:4:1
	2.	27:9:9:9:3:3:3:1
	3.	1:1:1:1:1:1::1:1
	4.	1:6:15:20:15:6:1
	5.	1:2:1

In wheat, seed color is a polygenic trait (additive model). If true- breeding red and white varieties are crossed, the F1 are intermediate in color. If the F1 are self-fertilized, about 1 in 256 have white seeds. How many genes control variation in color?

	a.	one
	b.	two
	c.	three
	d.	four
	e.	five

An inbred strain of plants has a mean height of 20 cm. A second inbred strain also has a height of 40 cm. Crossing the two strains produces an F ₁ that has a mean height of 30 cm. The F ₂ have a continuous range of heights was observed with most plants around 30 cm and 1 out of 1000 at 20-cm, and 1 out of 1000 at 40 cm. How much does each additive allele contribute to height?

	1.	1-cm
	2.	2-cm
	3.	3-cm
	4.	4-cm
	5.	5-cm

Please answer all and explain.Thank you!

Answer 1

Answer 1: Option C, D and E seems to more follow the parental phenotypes because all of these three, they have aither 2 or 1 dominant allele that make its height up to a certain level in both male and females, but option A and B does not follow the statement of question because both are of average height.

Answer 2: Correct answer is 4, because its a trihybrid cross in which there is a indefinite pattern of height is seen.

Answer 3:correct answer is 3 because it follows as kernel color of wheat, both are polygenic trait and 3 genes ABC and their recessive form make a gradient of color from dark red to white in a ratio of 1:6:15:20:15:6:1.

Answer 4: correct option is 5, lets take a example for it. Cross two inbred strain aabb(20cm) and AABB(40cm) then fr will be AaBb(30cm) right? If i further cross it with itself then all progeny will be of different heights. Difference between two parental progeny heights is 20 cm, so this would be contributed by four dominant alleles, each with 5 cm.