Question

In human beings 45 chromosomes with a single X / XO abnormality cause
A.Down syndrome
B.Turner syndrome
C.Klinefelter syndrome
D.Edward syndrome

Answer 1

In the case where a human, mostly female, only possesses one X chromosome, it is clinically identified as Turner's syndrome. There will only be 44 + 1 chromosomes instead of 44+2. Turner's syndrome is a genetic condition that results in symptoms such as a webbed neck, low hairline, short stature, etc.

Complete answer: Turner syndrome is a genetic abnormality that occurs in females wherein only one sex chromosome is present. This condition is also known as 45, X, denoting 44 somatic chromosomes + 1 X chromosome.
This condition is caused by errors during fertilization, such as monosomy or abnormalities in the father’s sperm or mother’s egg. Turner syndrome is usually detected prenatally, but in some cases, symptoms are only visible during childbirth or teenage.
Symptoms include a webbed neck, short stature, swollen palms, and infertility. People suffering from Turner syndrome cannot reproduce without fertility treatments and do not show proper sexual growth and require external hormone treatments.
Thus, the correct answer is B.Turner syndrome

Note: Turner syndrome is a form of monosomy where there is a deletion of one X chromosome. This is mainly seen in females and a common symptom includes a webbed neck.
Down syndrome is a genetic disorder where there is a third copy of the 21st chromosome also known as trisomy 21.
Klinefelter syndrome is a genetic disorder of the sex chromosome seen in males where there is an extra copy of the X chromosome or X trisomy. Where it is 44+ XXY. There could also be multiple copies of the X chromosome.
Edwards syndrome is a genetic disorder concerned with the trisomy of the 18th chromosome. Children suffering from Edwards syndrome, have severe birth defects such as loss of organ function, brain retardation, and physical disability.