Question

Which of the following is a sex-linked character?
A. White color blindness
B. Red blue color blindness
C. Night blindness
D. Sickle cell anaemia

Answer 1

Hint: Sex-linked characters are those characters of an individual which are controlled by the chromosomes responsible for the sexuality of that particular organism or individual. Each chromosome of the sex chromosome pair is inherited from each parent.

Complete answer:
In mammals, genome can be divided into two types of chromosomes that is, sex chromosomes and autosomal chromosomes. Autosomes are responsible for the characters like color of hair, color of eye, type of skin, etc. Sex chromosomes are responsible for the sexuality of the individual, sexual attraction, sexual hormonal regulation, etc.
Sex-linked characters are determined by the pair of chromosomes responsible for the sexuality of the individual and in case of mammals, sex chromosomes are X and Y. Males consist of XY pairs and females consist of XX pairs of chromosomes.
Generally, there are three main types of color blindness which happens to humans. These are divided on the bases of photopigment defects in the three different types of cones which detect the red, green and blue light.

Thus, we can conclude that Red blue colorblindness is a characteristic of sex chromosomes. And option ‘B’ is the correct answer.

Note: In case of sex-linked diseases, males are generally more affects because of presence of only one copy of X chromosome, which if get mutated then chances of getting diseases is very high. But in the case of females, chances are very low because of two copies of X chromosome. If one copy gets mutated a second copy is present to work properly. Thus, females generally act as carrier of the sex chromosomal disorders.