Question

Crotons are a type of plant that has either solid green leaves or variegated yellow-spotted leaves. The variegated form is due to a mutation in the chloroplasts of the plant.
When pollen from a green-leafed croton is used to pollinate a variegated croton, all of the seeds the variegated croton progeny exhibit variegation.Why?

• A. Variegation is a dominant trait that masks the appearance of the green-leafed appearance.
• B. Leaf variegation is said to be recessive genetic trait that is maternally inherited. Though the pollen is from green leafed croton, since the variegated croton is maternal parent the progeny exhibited variegation.
  
• C. Variegation is inherited maternally through genes in the chloroplasts of the female gamete since the pollen (male gamete) contributes little more than a nucleus to the zygote formed.
• D. The seeds of the plant grow into variegated leaves due to the amount of available sunlight.

Answer 1

The correct option is C Variegation is inherited maternally through genes in the chloroplasts of the female gamete since the pollen (male gamete) contributes little more than a nucleus to the zygote formed.

Variegation is inherited maternally, that is, from the plant contributing the egg during zygote formation. It is transferred from the genetic material of the chloroplast present in the egg. Therefore, presence or absence of variegation depends on the type of genes present in the chloroplast of the female plant. This is also referred to as maternal inheritance or cytoplasmic inheritance.

So, the correct answer is ' Variegation is inherited maternally through genes in the chloroplasts of the female gamete since the pollen (male gamete) contributes little more than a nucleus to the zygote formed'