Question 3

One daughter cell will receive an extra chromosome, and one will be short a chromosome.

If a pair of sister chromatids fails to split during anaphase, the result will be that one daughter cell receives both chromatids while the other receives none. This leads to one daughter cell having an extra chromosome and the other being deficient by one chromosome.

A) The pair of sister chromatids will be lost from both daughter cells

This option is incorrect because if the sister chromatids fail to separate, they do not get lost; rather, they are distributed unevenly between the two daughter cells. One cell retains both chromatids while the other cell ends up with none.

B) Mitosis will halt, and no daughter cells will be created

This option is also incorrect. While improper separation may lead to complications, it does not halt mitosis entirely. Mitosis can still proceed, resulting in cells with unequal chromosome numbers rather than stopping completely.

C) Each daughter cell will receive the correct number of chromosomes

This option is incorrect as well. If the sister chromatids do not separate, the daughter cells will not receive the correct number of chromosomes. Instead, one will have an extra chromosome while the other will have one less.

D) One daughter cell will receive an extra chromosome, and one will be short a chromosome

This option is correct because it accurately describes the outcome of a failure in sister chromatid separation during anaphase. One daughter cell ends up with both chromatids, resulting in an extra chromosome, while the other daughter cell is left without that chromosome.

Conclusion

The correct answer, D, highlights the consequences of a failure in sister chromatid separation during anaphase, leading to aneuploidy in the daughter cells. Options A, B, and C either misrepresent the effects of this failure or misstate the outcomes, demonstrating a misunderstanding of chromosomal distribution during mitosis.