Question

Cross 1 Progeny:
38 two-lobed, red
18 two-lobed, yellow
38 multilobed, red
18 multilobed, yellow

Cross 2 Progeny:
14 two-lobed, red
14 two-lobed, yellow
14 multilobed, red
14 multilobed, yellow

In tomato plants, the production of red fruit color is under the control of an allele R. Yellow tomatoes are rr. The dominant phenotype for fruit shape is under the control of an allele T, which produces two lobes. Multilobed fruit, the recessive phenotype, have the genotype tt. Two different crosses are made between parental plants of unknown genotype and phenotype. Use the progeny phenotype ratios to determine the genotypes and phenotypes of each parent.

PART A: For cross 1, determine two appropriate genotypes for both parents.

a) Rrtt × Rrtt

b) Rrtt × rrTt

c) RrTt×Rrtt

d) Rrtt × RrTt OR rrTt × RrTt

Part B: For cross 1, determine two appropriate phenotypes for both parents.

a) yellow fruit, two lobes AND red fruit, multiple lobes

b) red fruit, two lobes AND red fruit, two lobes

c) red fruit, two lobes AND red fruit, multiple lobes

d) red fruit, two lobes AND yellow fruit, two lobes

PART C: For cross 2, determine two appropriate genotypes for both parents.

a) RrTt × Rrtt

b) RrTt × rrtt

c) RrTt × rrTt

d) RrTt × rrtt OR Rrtt × rrTt

Answer 1

Part A - Answer C - RrTt×Rrtt

Gametes RT, Rt, rT, rt X Rt rt

	Rt	rt
RT	RRTt Red, Two lobed	RrTt Red, Two lobed
Rt	RRtt   Red, Multi lobe	Rrtt   Red, Multi lobe
rT	RrTt   Red, Two lobed	rrTt   Yellow, Two lobed
rt	Rrtt   Red, Multi lobe	rrtt    Yellow, Multi lobed

Other option not given this trait.

Option D rrTt × RrTt not given the following ratio

Part B - RrTt×Rrtt

The phenotype are RrTt - Red, Two lobed and Rrtt - Red, Multi lobed

Part C- Answer d - RrTt × rrtt OR Rrtt × rrTt