Individuals with karyotype of 44+XXY having overall masculine development with few feminine development like Gynaecomastia has________chromosomal disorder.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Klinefelter’s Syndrome
Option (1) Klinefelter’s Syndrome — Correct. An extra X chromosome (47, XXY) gives male development on the whole with some female features such as breast development (gynaecomastia). Such individuals are sterile.
Option (2) Turner’s Syndrome — Incorrect. Turner’s syndrome is the absence of one X (45, X0) in females.
Option (3) Down’s Syndrome — Incorrect. Down’s syndrome is an extra chromosome 21, an autosome.
Option (4) Acquired Immuno Deficiency Syndrome — Incorrect. AIDS is caused by HIV infection, not by a chromosome change.
NCERT Extract:
Chromosomal Disorders – “… Klinefelter’s Syndrome : This genetic disorder is also caused due to the presence of an additional copy of X-chromosome resulting into a karyotype of 47, XXY. Such an individual has overall masculine development, however, the feminine development (development of breast, i.e., Gynaecomastia) is also expressed (Figure 4.17 a). Such individuals are sterile.”
Figure 4.17 Diagrammatic representation of genetic disorders due to sex chromosome composition in humans : (a) Klinefelter Syndrome; (b) Turner’s Syndrome