A particular cell has a mutation that causes it to make defective centromeres. What would you expect to occur during mitosis for this cell ?

Chromosomes will not align at the equator of the cell, and subsequently will not separate to opposite poles.

Explanation:

Mitosis is a cellular division that results in daughter cells with identical copies of the genetic material as the parent cell. Mitosis is characterized by different stages viz: Prophase, Metaphase, Anaphase, and Telophase. The centromere is a very important part of the cell during division as it produces microtubules that grows out and bind to the kinetochore of each chromosome, hence, aligning them at the CELL PLATE (cell equator) and subsequently pulls them apart to opposite poles. This alignment and pulling apart occurs during METAPHASE and ANAPHASE respectively.

Mutation is any change that occurs in the nuceleotide sequence of the genetic material (DNA). If a change/mutation occurs leading to a defective or non-functional centromere, the centromere will no longer be able to produce microtubules that will bind to the kinetochores of each chromosome. Therefore, the chromosomes will be unable to align at the equator/middle of the cell and most importantly, inability to separate to opposite poles, which is the main point of Mitosis.