In plants, the ability to synthesize chlorophyll is transmitted as a dominant autosomal trait.

In plants, the ability to synthesize chlorophyll is transmitted as a dominant autosomal trait. A recessive gene in a homozygous state leads to a lethal effect and alibino plants die. What is the probability of plant death from crossing heterozygous parents capable of synthesizing chlorophyll?

Let’s designate the gene that determines the plant’s ability to synthesize chlorophyll as C, then the gene that makes it impossible to synthesize chlorophyll will be c.

Heterozygous Cc plants will synthesize chlorophyll. They will produce sex cells of two types – c and C.

When crossing heterozygotes, we get offspring, including the following options:

plants – homozygotes capable of photosynthesis (CC) – 25%;

plants – heterozygotes capable of photosynthesis – 50%;

plants are homozygotes that do not synthesize chlorophyll and die as a result (cc) – 25%.

Answer: 25%.