Question

While examining the mitotic stage in a tissue, one finds some cells with 16 chromosomes and some with 32 chromosomes. What possible reasons could you assign to this difference in chromosome number. Do you think cells with 16 chromosomes could have arisen from cells with 32 chromosomes or vice versa?

Answer 1

The given condition may arise in case of mosaicism or mosaic, this denotes the presence of two or more population of cells with different genotypes in one individual.

This condition can result from various reasons such as non-disjunction, endoreplication, and anaphase lagging. It can also result due to mutation during development which is passed on to only a subset of the adult cells.

Considering a cell with 16 chromosomes as a parent cell undergoing mitosis, it can be concluded that cells with 32 chromosomes have arisen from the cells with 16 chromosomes. They have double the number of chromosomes between the period of separation of chromatids containing duplicated DNA and cytokinesis.