Question

Which one of the following conditions in humans is correctly matched with its chromosomal abnormality/linkage?

• A. Down’s syndrome ­- 44 autosomes + XO
• B. Erythroblastosis foetalis -­ X-­linked
• C. Colour blindness­ – Y-­linked
• D. Klinefelter’s syndrome­ – 44 autosomes + XXY

Answer 1

The correct option is D

Klinefelter’s syndrome­ – 44 autosomes + XXY

The correct option is D.

The explanation of the correct answer :

1. Klinefelter's syndrome is caused by an extra X chromosome over the XY chromosome.
2. There are 47 chromosomes in all, with 44 autosomes and three XXY sex chromosomes.
3. They are male but have feminine characteristics such as gynecomastia.

The explanation of the incorrect answer :

OPTION A:

The trisomy of chromosomal number 21 causes Down's syndrome.

OPTION B:

Erythroblastosis fetalis is a condition that affects babies and is caused by the Rh factor.

OPTION C:

The X chromosome contains the gene that causes color blindness.

Final Answer: Klinefelter’s syndrome­ – 44 autosomes + XXY is the condition in humans with its chromosomal abnormality/linkage.