Question

The plant coleus has three distinct leaf color phenotypes: green, white, and variegated (white and green mixed) the crosses are made as follows: female variegated leaves × male green leaves gives offspring with all variegated leaves female green leaves × male with white leaves gives offspring with all green leaves female with white leaves × male with variegated leaves gives offspring with all white leaves This is an example of ________.

Answer 1

Answer:

Cytoplasmic inheritance

Explanation:

• female variegated leaves × male green leaves ⇒ all variegated leaves
• female green leaves × male with white leaves ⇒ all green leaves
• female with white leaves × male with variegated leaves ⇒ all white leaves

From these crosses, we can notice that only the female´s phenotype is expressed in the progeny, independently of the male´s phenotype. Whenever this occurs, it is probably due to the action of cytoplasmic inheritance.

Extrachromosomal or cytoplasmic inheritance refers to hereditability transmission controlled by cytoplasmic genes.

This form of inheritance lays in genes that are out of the nucleus. Even though most of the DNI is located in the nucleus, information for some characters is placed in organelles in the cytoplasm, such as mitochondria and chloroplasts. These organelles have a well-defined portion of the total cellular genome.

When a female expresses a trait that is defined by genes in the organelles, the whole progeny expresses the same trait as the female.

Mitochondrial inheritance is mostly maternal, but recent studies have demonstrated that it might also be paternal.