Question

QUESTION 3 A test cross is set up to establish the genotype of a plant with rounded peas. It is crossed with a plant that is homozygous for wrinkled peas. A round pea shape is dominant over the wrinkled shape. The offspring derived in the test cross exhibit a 50:50 ratio of wrinkled and round peas. What is the genotype of the parent in question? Homozygous for round pea shape. Heterozygous for pea shape. Homozygous for wrinkled pea shape. Heterozygous for flower color. QUESTION 4 The associated image shows a Punnett square depicting a couple's likelihood of having a child with lactose intolerance (denoted here by the ir genotype. Based on the image, what percentage chance do the parents have of producing a lactose intolerant child? Homozygous recessive Click Save and Submit to save and submit. Click Save All Answers to save all answers

Answer 1

1) the seed shape is considered here

let the alleles be R- round, r-wrinkled

round seed shape is dominant to the wrinkled seeds if the round seeded plant was homozygous dominant RR

RR * rr

Rr

all the progenies would have round seeds.

if the round seeded plant is Rr

Rr * rr

	R	r
r	Rr ( round)	rr ( wrinkled)
r	Rr ( round)	rr ( wrinkled)

the expected ratio of round; wrinkled=1:1

so the answer is B) heterozygous for the pea shape.

9) pleiotropic gene is the gene which affects multiple phenotypes,

the epistatic gene affects the phenotype produced by the other locus.

so the answer is B) A gene involved in multiple phenotypes like pigmentation, hearing and intestinal traits.

10) colorblindness is a sex-linked recessive trait. so a female is affected when both the X chromosomes have mutated alleles and the normal man has no mutated allele.

let the alleles be XC- normal vision, Xc- colorblind

the genotype of the woman is XcXc and genotype of the man is XCY

XCY * XcXc

	Xc	Xc
XC	XCXc ( carrier, phenotypically normal female)	XCXc( carrier, phenotypically normal female)
Y	XcY ( colorblind son)	XcY (colorblind son)

here all male children are colourblind so the answer is c) all male children will be colourblind.