Examkin

Question

Difficulty: Very hardGene Mutations and Chromosomal Aberrations

A paracentric inversion is a structural chromosomal aberration involving two double-strand breaks on a chromosome followed by a 180-degree rotation of the detached segment including the centromere, thereby altering the chromosome's relative arm length ratio.

Answer: Answer

Answer

The statement is False. A paracentric inversion occurs within a single arm of a chromosome and does not involve the centromere. A pericentric inversion is the type of inversion that includes the centromere and can change the arm length ratio.
The statement is false because a paracentric inversion is restricted to a single chromosome arm and does not incorporate the centromere. Therefore, it cannot alter the centromere's position or the arm ratio of the chromosome.

Step-by-Step Solution

1
Define structural chromosomal inversions
Inversions occur when a segment of a chromosome breaks at two points, rotates 180 degrees, and reinserts into the chromosome.
Establishing the general mechanism of inversion aberrations.
2
Distinguish between paracentric and pericentric inversions based on centromere involvement
Para- means 'next to' or 'beside' (confined to one arm, excluding the centromere). Peri- means 'around' (spans across the centromere).
Identifying which structural inversion type contains the centromere.
3
Evaluate the morphological impact on chromosome arm ratios
Because paracentric inversions take place entirely within one arm, the centromere remains intact in its original location, leaving the relative lengths of the short (pp) and long (qq) arms unchanged. Pericentric inversions can change the centromere position relative to the ends, changing arm ratios.
Determining the truth value of the stem's claim.

Key Concept

Paracentric versus Pericentric Chromosomal Inversions
Estimated Time:1m 30s
Rate this question

Topics

Gene Mutations and Chromosomal Aberrations

More questions from this topic