Question

From a large-scale screen of many plants of collinsia grandiflora, a plant with three cotyledons was discov- ered (normally, there are two cotyledons). this plant was crossed with a normal pure-breeding wild-type plant, and 600 seeds from this cross were planted. there were 298 plants with two cotyledons and 302 with three cotyledons. what can be deduced about the inheritance of three cotyledons? invent gene symbols as part of your explanation.

Answer 1

Inheritance refers to the procedure by which genetic information is conducted from the parent to the offspring. In the given case, regarding the inheritance of the three cotyledons indicates towards the fact that approximately half of the F1 progeny are mutant, and the mutation that results in three cotyledons is dominant and the original mutant was heterozygous.

If C is the mutant allele and c the wild type allele, the cross will be between the  parents exhibiting genotypes Cc and cc. Thus, the F1 progeny will possess Cc three cotyledons and cc two cotyledons.