Question

Male cat is either black or orange because of ……..
(a)Hemizygous- X
(b)Heterozygous- Y
(c)Heterozygous- X
(d)Hemizygous- Y

Answer 1

Hint: It is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it's the degree of similarity of the alleles in an organism. It is the condition in which one allele is missing.

Complete answer:
Biological sex is decided by a pair of sex chromosomes: for which XY in males and XX in females, in humans and other mammals.
Hemizygous may be a condition during which just one copy of a gene or DNA sequence is present in diploid cells. Males are hemizygous for many genes on sex chromosomes, having just one X and one Y chromosome.
Both male and feminine cats are often orange or black because the gene that controls orange fur color is on the X chromosome.
Because the X chromosome is liable for both orange and black fur, female cats can display both colors because they need two X chromosomes. But males, having just one X chromosome, are often either orange or black.

Additional Information: A chromosome during a diploid organism is hemizygous when just one copy is present. The cell or organism is called a hemizygote. Hemizygosity is additionally observed when one copy of a gene is deleted, or, within the heterogametic sex when a gene is found on a chromosome. Hemizygosity must not be mistaken for haploinsufficiency, which depicts a system for creating a phenotype. For life forms during which the male is heterogametic, similar to people, most X-linked genes are hemizygous in males with typical chromosomes, since they need only one X chromosome and few the equivalent genes are on the Y chromosome.
So the correct answer is ‘Hemizygous- X’.

Note: Transgenic mice created through exogenous DNA microinjection of an undeveloped organism's pronucleus likewise are viewed as hemizygous on the grounds that the acquainted allele is anticipated to be consolidated into only one copy of any locus. A transgenic individual can later be bred to homozygosity and maintained as an inbred line to scale back the necessity to verify the genotype of every individual.
In cultured mammalian cells, like the Chinese hamster ovary cell line, a variety of genetic loci are present during a functional hemizygous state, thanks to mutations or deletions in the other alleles.