Many genotypic and phenotypic characteristics are linked to the X chromosome. Some of these are caused by X-linked traits, whereas others are due to X chromosome inactivation. Drag the labels on the left to the appropriate category on the right. Calico cats have patches of black and orange fur X inactivation X-linked Color blindness is more common in men "Heterozygotes" can express the recessive phenotype Hemophilia Rett syndrome is not always fatal in females Barr bodies

X chromosome inactivation:

- Calico cats have patches of black and orange fur

- "Heterozygotes" can express the recessive phenotype

- Rett syndrome is not always fatal in females  

- Barr bodies

X linked traits:

- Color blindness is more common in men  

- Hemophilia  

Explanation:

X chromosome inactivation refers to the mechanism in which one X chromosome is randomly inactivated during early embryonic development in female mammals. The inactivated (silenced) X chromosome is condensed into a structure called Barr body. In cats, the gene encoding for the orange/non-orange fur coloring is X-linked, thereby X inactivation explains why most calico cats (i.e., those cats that have a color pattern with orange and black spots) are female. Moreover, Rett syndrome is a neurodevelopmental disorder caused by a mutation in the X-linked MECP2 gene, and therefore this disorder is much more serious in males. On the other hand, color blindness is more common in men because males have only one X chromosome. In the same way, hemophilia, which is a disorder caused due by a mutation in one gene required for synthesizing one clotting factor, is more common in males than in females because the gene responsible for this disorder is located on the X chromosome.