Question

In structural chromosome mutations pericentric inversion mutation means

• A. A portion in the chromosome is reversed and gets inserted back into the other arm of the same chromosome
• B. Some part of the chromosome is deleted and new is added
• C. A portion in the chromosome is reversed and gets inserted back into the same arm of the chromosome
• D. A portion in the chromosome is reversed and gets inserted back into the other chromosome

Hint:

• Inversion A chromosomal segment is detached, rotated 180 degrees, and reinserted.
• Paracentric Inversion Does NOT include the centromere. Breaks are in one arm.
• Pericentric Inversion DOES include the centromere. Breaks are in different arms (one on each side of the centromere). Can change arm length ratio.

Answer 1

The Correct Option is A

In the context of structural chromosome mutations, a pericentric inversion refers to a specific type of inversion mutation where a segment of a chromosome is reversed and inserted back into the chromosome. Importantly, during a pericentric inversion, the inverted segment includes the centromere. This results in the changed orientation of segments on either side of the centromere being rearranged. Thus, the segment of the chromosome gets inverted and is inserted back into the opposite arm of the same chromosome.

Key Feature	Explanation
Location of Change	A segment including the centromere
Re-insertion	Back into the opposite arm

Hence, the correct description for a pericentric inversion mutation is: "A portion in the chromosome is reversed and gets inserted back into the other arm of the same chromosome."