Solutions For An Introduction to Genetic Analysis Chapter 17 Problem 35P

A dicentric bridge at meiosis indicates a crossover within a paracentric inversion heterozygote. This crossover gives a product of a dicentric bridge and an acentric fragment. An acentric fragment is a deoxyribonucleic acid (DNA) fragment without a centromere.

This bridge can be formed in the following steps:

• The telomere of a chromosome breaks off

• After replication, both sister chromatids lack telomeres

• The lack of telomeres cause both the sister chromatids to fuse together

• In the stage of anaphase, the centromere of each sister chromatid will pull in opposite directions

• This causes the formation of the dicentric bridge with two centromeres

• The bridge later breaks unevenly incorporating different fragments into daughter cells