NEET PG Medical – 2012 – Question – 21
Y chromosome is ?
a) Metacentric
b) Submetacentric
c) Acrocentric
d) None
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Correct Answer – C
Ans. is ‘C’ i.e., Acrocentric
Each chromosome has two arms :-
1. p arm (the shorter of two)
2. q arm (longer one
Depending on the position of there junction (centromere) they can be classified into :
1. Metacentric
- The centromere is in the middle so that the two arms of chromosomes are almost equal.
- These chromosomes are : chromosomes 1, 2, 3 and Xchromosome.
2. Submetacentric
- p arm is short and q arm is long. These chromosomes are : 4, 5, 6, 7, 8 and 9
3. Acrocentricp
- (short) arm is so short that it is hard to observe, but still present.
- There are six acrocentric chromosomes : 13, 14, 15, 21, 22 and Y chromosomes
