Question

Look at the four cells at the end of

this model of meiosis. What could
have caused them to have an irregular
number of chromosomes? Explain this
process.

Answer 1

non-disjunction

Step-by-step explanation:

During meiosis, errors can occur, resulting in an irregular number of chromosomes in the resulting cells. One such error is called non-disjunction. Non-disjunction can happen in either meiosis I or meiosis II and involves the failure of chromosomes to separate properly.

If non-disjunction occurs in meiosis I, it means that homologous chromosomes fail to separate, resulting in one cell receiving both chromosomes and the other cell not receiving any. This leads to a pair of cells with an irregular number of chromosomes (one cell with an extra chromosome and the other missing a chromosome).

If non-disjunction occurs in meiosis II, it means that sister chromatids fail to separate, resulting in one cell receiving both chromatids and the other cell not receiving any. Again, this leads to a pair of cells with an irregular number of chromosomes.