Question

Select the incorrect statement from the following?
(a) Baldness is a sex-linked trait
(b) Linkage is an exception to the principle of independent assortment
(c) Galactosemia is an inborn error of metabolism
(d) Small population size results in random genetic drift in a population

Answer 1

Most of the observable features of organisms which are controlled by the genes on the chromosomes are the sex-linked characters that determine the organism's sex. The pair of sex chromosomes are present in each individual. One is inherited from each parent.

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. On the sex chromosome, sex-linked traits are present. In the case of a man are present on the chromosome that is found in the egg cells. While sex-influenced is the condition in which due to the influence of sex hormosomes various autotosomal traits express their genes. Example in the case of females due to the hormone progesterone various changes occur in the body while in the case of males it occurs due to the presence of testosterone. Baldness also comes under teh category of the sex-influenced traits. In males the chromosoems are in hetwerozygous conditions having X and Y chromosomes. The aegean present on these chromosomes may get influenced due to the sex hormones secreted by the person. A female will always inherit only one X chromosome from her father. Because the woman’s mother only carries one copy of the allele and doesn’t carry the allele for pattern baldness. If the couple has a son, there’s a $50\%$ chance that the son will inherit the X-linked allele for pattern baldness from his mother.

So the incorrect statement is option a) Baldness is a sex-linked trait.

Additional information:
It is observed that in the case of recombination the maternal and paternal genes are further apart resulting in the independent assortment of the genes. While in the case of linkage the aegean are located too close to each other and still follows the law of independent assortment which is an exception. Galactosemia is a disability which is genetic and rare. It is the condition in which the movement of galactose in the body becomes slow due to lack of enzyme resulting in the accumulation of galactose sugar in the blood. The genetic drift occurs due to mutation resulting in the change that occurs over generations in the allelic frequency of the population by chance.

Note:
In male-pattern hair loss (MPHL), it was seen that the hair loss often presents itself as either a receding hairline, loss of hair on the crown of the scalp, or a mixture of both, on the other hand in female-pattern hair loss , which typically presents as a thinning of the hair.