Question

Sex-linked traits of a man are present on --------.
(a)X-chromosome
(b)Autosomes
(c)Short arm (p) of Y-chromosome
(d)Long arm (q) of Y-chromosome

Answer 1

On the sex chromosome, sex-linked traits are present. Other than sex chromosomes, chromosomes are considered autosomes. Sex-linked traits of a man are present on the chromosome that is found in the egg cells. Turners syndrome happens when this chromosome has a mutation.

Complete answer:
Humans have sex chromosomes X and Y; chromosomes other than sex chromosomes are considered autosomes. The one that is inherited with sex chromosomes is the sex-linked characteristics, so sex-linked characters cannot be present on autosomes.
-Y is the smallest chromosome in the human genome (approximately 60 Mb) with pseudoautosomal regions (PAR), PAR1, and PAR2, located in the short-arm (p) and long-arm (q) terminal regions of the Y chromosome, respectively.
-The Y and X chromosomes are homologous regions. Thus, as autosomal genes, the genes found inside the PAR are inherited and do not have sex-specific genes.
-The majority of the Y-chromosomes have euchromatic (genetically active) and heterochromatic (genetically inert) regions; the presence in the euchromatic region of multiple widely replicated sequences further decreases the probability of genes responsible for essential biological functions being present.
The limited size of Y chromosomes and the inclusion of heterochromatic regions and repeated sequences restrict the space available for sex-linked genes, most of which are X-chromosome-linked.
-Males are considered to be hemizygous because for every X-linked trait they have only one allele; males will show the trait of any gene on the X-chromosome regardless of dominance and recessiveness.
-Father transmits to the daughters the affected X-chromosome allele present, while the mother transmits it to both son and daughters. Y-chromosomes are only found in males and bear very few genes. Therefore, the level of transmission of characters linked to sex through Y is very low.
So, the correct answer is, ‘X-chromosome’.

Note: -Females have a homologous pair of X chromosomes in mammals, while men have XY chromosomes. A small area of resemblance to the X chromosome is found in the Y chromosome so that they can pair during meiosis, but the Y is much shorter and contains fewer genes.
-Most sex-linked characteristics, such as eye color in Drosophila or color blindness in humans, are simply X-linked.