Match List-I with List-II

Choose the correct answer from the options given below.

(A)-(III), (B)-(IV), (C)-(II), (D)-(I)

The correct answer is Option (1) → (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

A. Color Blindness: It is a sex-linked recessive disorder due to defect in either red or green cone of eye resulting in failure to discriminate between red and green colour. This defect is due to mutation in certain genes present in the X chromosome. It occurs in about 8 per cent of males and only about 0.4 per cent of females. This is because the genes that lead to red-green colour blindness are on the X chromosome. Males have only one X chromosome and females have two. 

B. Haemophilia is a sex linked recessive disease, which shows its transmission from unaffected carrier female to some of the male progeny has been widely studied. In this disease, a single protein that is a part of the cascade of proteins involved in the clotting of blood is affected. Due to this, in an affected individual a simple cut will result in non-stop bleeding.

C. Down's syndrome, also known as Trisomy 21, is a genetic disorder caused by the presence of an extra copy of chromosome 21. Instead of the typical two copies of chromosome 21, individuals with Down's syndrome have three copies, leading to a total of 47 chromosomes in their cells instead of the usual 46. Down's syndrome (Trisomy 21) affects both males and females because it is related to the gain of an autosome (chromosome 21) and not to sex chromosomes.The affected individual is short statured with small round head, furrowed tongue and partially open mouth. Palm is broad with characteristic palm crease. Physical, psychomotor and mental development is retarded.

D. Turner’s Syndrome : Such a disorder is caused due to the absence of one of the X chromosomes, i.e., 45 with XO, Such females are sterile as ovaries are rudimentary besides other features including lack of other secondary sexual characters.