Question

Sex-linked traits are always-
A.Lethal
B.Recessive
C.Dominant
D.Pleiotropic

Answer 1

A sex-linked trait is defined as a trait that is controlled by a gene or an allele located on the sex chromosome. In humans, sex chromosomes are X-chromosome and Y-chromosome.

Complete step by step answer: Sex-linked traits are mainly influenced by genes on the X-chromosome. The reason being X-chromosome are so large and have more genes than Y-chromosomes. In sex-linked traits mostly men are affected because they have a single copy of the X-chromosome that carries the mutation. The effect of one X-chromosome can be masked by a healthy X-chromosome in females leaving less effect. The effect is suppressed by the recessiveness of the affected gene. Since these traits are sex-linked they follow a distinct pattern. Some traits being linked to either sex or gender of an individual. Taking an example of color blindness is referred to as a sex-linked trait whose trait being recessive is located on the X-chromosome. Some more familiar sex-linked traits are types of blindness including green color blindness and congenital blindness, high blood pressure genes, and also fragile X syndrome. So from these, we can imagine the individuals with XY sex chromosomes or males are most problematic because the mutations are mostly on the X-chromosome and in males, there is no another X-chromosome to mask its effect. In females being recessive their effect is not seen in the females. They have more potential of carrying a healthy and defective gene both but being recessive it is not seen. The conclusion is males are more affected.
So, the correct answer to this question is the option"B".

Note: Sex-linked traits are the inheritance from parents are to the progeny and is associated with the defects on the genes they are not treated and persists for life. Sex-linked traits create life problems leading to serious effects on the patients.