Turner's syndrome is characterized by chromosomes

Concept: 

• A normal Human has 23 pairs of chromosomes (46 chromosomes) out of which 22 pairs are autosomes or allosomes (Non - sex chromosomes), while the 23rd pair is the sex chromosome which is responsible for the hereditary changes.
• One - One chromosome each in the sex chromosome pair comes from the maternal and paternal side respectively.
• Any deviation from this normal arrangement may result in a disorder or syndrome.
• These disorders may arise either by addition, deletion, or nonfunctioning of a single or multiple chromosomes.
• Examples of such disorders are Turner syndrome, Edward's syndrome, Patau's syndrome, Klinefelter's syndrome, etc.

Explanation:

• Turner's syndrome: It is caused due to the absence of one X-chromosome in the females i.e. Karyotype 45, (44 + XO).
• Such females are sterile with underdeveloped breasts, short stature, reduced ovaries & absence of menstrual cycle.

Klinefelter's syndrome:

• It occurs due to the trisomy of the X- chromosome in a male, resulting in a karyotype of 47, (44+ XXY). 
• Individuals have long legs, sparse body hair, small prostate gland, small testes, reduced mental intelligence, and enlarged breasts (Gynaecomastia).
• Such individuals are sterile.

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