Question

a market gardener crossed a tomato plant that had yellow fruit with one that had red fruit. this crossing resulted in 302 seeds. when these seeds matured into plants, 147 had yellow fruit and 155 had red fruit. which of the following punnett squares represents the cross?

Explanation:

Step1: Analyze the ratio of offspring

The ratio of yellow - fruit plants to red - fruit plants is approximately 147:155, which is close to 1:1. A 1:1 ratio in a monohybrid cross is typically the result of a cross between a heterozygous individual and a homozygous recessive individual.

Step2: Evaluate each Punnett - square

• In a Punnett - square representing a cross between a heterozygous (Cc) and a homozygous recessive (cc) individual, the genotypes of the offspring will be Cc and cc in a 1:1 ratio.
• For the first Punnett - square: It has a 1:1 ratio of Cc and cc genotypes.
• The second Punnett - square has all Cc genotypes (100% heterozygous), which would not give a 1:1 ratio of phenotypes.
• The third Punnett - square has a 3:1 ratio of dominant to recessive genotypes (CC:Cc:cc = 1:2:1), not a 1:1 ratio.
• The fourth Punnett - square has a 1:2:1 ratio of genotypes (CC:Cc:cc = 1:2:1), not a 1:1 ratio.

Answer:

The first Punnett - square (the one with Cc and cc genotypes in a 1:1 ratio) represents the cross.