Question

punnet square questions

2. At a separate locus, cats have a gene that controls how densely the melanin is deposited e hair. The dense (D) deposit results in black or brown cats and is dominant to the dilute version. Dilute black cats are gray (technically it called blue) and dilute brown cats are a light brown called lilac. Romeo and Juliet are both heterozygous for both loci. Ose Punnett squares and probability rules to solve the following. Draw the Punnett squares here: (2 pts) ob aB ab A air AB TAABB AALB Ab AABb AA 66 ABB AbB/ GABbcAbb. au BB aubB BB: Au BB Aab B BG: bhi is ab A.Bb | Aubb aaBb | aubb! a. What is the probability that Romeo and Juliet will have a lilac kitten? (0.5 pt) 6.26% b. What is the probability that Romeo and Juliet will have a blue kitten? (0.5 pt) - 18.75% C. What is the probability that Romeo and Juliet will have a brown kitten? (0.5 pt) 56.25% d. What is the probability that Romeo and Juliet will have a black kitten? (0.5 pt) 56.25%

Answer 1

Let the alleles be D-dense, d-dilute A-black, a- brown

2 heterozygous cats are crossed

DdAa * DdAa

	DA	Da	dA	da
DA	DDAA (black)	DDAa (black)	DdAA (black)	DdAa (black)
Da	DDAa (black)	DDaa (brown)	DdAa (black)	Ddaa (brown)
dA	DdAA (black)	DdAa (black)	ddAA (blue)	ddAa (blue)
da	DdAa (black)	Ddaa (brown)	ddAa (blue)	ddaa (illiac)

a) probability of getting illiac= number of illiac/total number=1/16= 0.0625

that 6.25%

b) probability of getting blue= number of blue/total number=3/16=0.1875

that is 18.75%

c) probability of getting brown = number of brown/total number= 3/16=0.1875

that is 18.75%

d) probability of getting black= number of black/total number=0.5625

that is 56.25%

3) aadd * AaDd

	AD	Ad	aD	ad
ad	AaDd(black)	Aadd (blue)	aaDd (brown)	aadd (illiac)

here all phenotypes are produced equally which is 25% each so the probability of getting each is 1/4 or 25%.

a) 1/4 (25%)

b) 1/4 (25%)

c) 1/4 (25%)

d) 1/4 (25%)