6. Chromosomal Variation

A person has a WT chromosome with the following segments. A B C • D E F G H. Which of the following shows how the chromosome would look after an paracentric inversion?

A person has a WT chromosome with the following segments. A B C • D E F G H. Which of the following shows how the chromosome would look after a pericentric inversion?

From the following list, identify the types of chromosome changes you expect to show phenotypic consequences.

Pericentric inversion

Inversions are said to 'suppress crossing over.' Is this terminology technically correct? If not, restate the description accurately.

Contrast the genetic composition of gametes derived from tetrads of inversion heterozygotes where crossing over occurs within a paracentric versus a pericentric inversion.

A normal chromosome and its homolog carrying a paracentric inversion are shown here. The dot (·) represents the centromere.

Normal    ABC • DEFGHIJK

Inversion  abc • djihgfe

Assume a crossover takes place in the region between A and B. Identify the gametes that are formed by this crossover event, and indicate which, if any, gametes are viable.