Question

In human beings 45 chromosomes/ single X/XO abnormality causes:

• A. Kinefelter’s syndrome
• B. Down’s syndrome
• C. Edward’s syndrome
• D. Turner’s syndrome

Answer 1

The correct option is D

Turner’s syndrome

The correct option is D.

Explanation of Correct answer:

1. Turner's syndrome is a syndrome that occurs in females. Females with this disorder have 45 chromosomes instead of 46.
2. They lack one X chromosome(XO).
3. Persons with this disorder have retarded sexual growth, are usually sterile, of short stature, webbing of skin in the neck region, cardiovascular abnormalities, and hearing problems.

Explanation of Incorrect answer:

Option A:

1. Klinefelter’s syndrome occurs in males.
2. They have 47 chromosomes with one additional X chromosome(XXY).
3. Symptoms include small testes, developed breasts, and feminine pitched voice.

Option B:

1. People with down syndrome have an extra copy of chromosome 21(trisomy 21).
2. The main symptoms are decreased muscle tone, asymmetrical skull, and mental retardation.

Option C:

1. Edward’s syndrome is trisomy of chromosome 18(extra copy of chromosome 18).
2. Symptoms include mental and motor retardation and numerous congenital anomalies.

Final Answer: In human beings, 45 chromosomes/ single X/XO abnormality causes Turner's syndrome.