Question

What is criss-cross inheritance? Explain the inheritance of one sex-linked recessive character in human beings.

Answer 1

Hint: Some genes are transferred from the female parent of the first generation to the male progeny of the next generation and from male parents of the first generation to the female progeny of the next generation.

Complete answer:
The criss-cross inheritance is the transmission of a gene from father to the daughter or from mother to the son. This pattern of inheritance of genes is also called skip generations because the character is inherited to the second generation through the carrier of the first generation. The genes which are present on the X-chromosome but not on the Y-chromosome lead to a criss-cross pattern of inheritance. For a recessive trait that is controlled by a gene on the X-chromosome, the features of inheritance will be
In the next generation, more males will show the character in comparison to the females.
A male with that trait cannot pass that trait to the sons of the next generation.
Carrier females do not show the trait but pass the trait to the sons.
All the daughters of the affected males will at least be the carriers of the trait.
In the X-linked recessive inheritance, mainly the male offspring are affected due to the presence of a single X-chromosome.

Note: The sex-linked characters that are controlled by the genes present on sex chromosomes are divided into two categories:
Sex-influenced traits – baldness in humans is an example of such a trait.
Sex-limited traits – female sterility in Drosophila is an example of such a trait.