What occurs during total non-disjunction in meiosis?

Total non-disjunction during meiosis refers to the failure of homologous chromosomes or sister chromatids to separate properly during cell division. When this occurs in meiosis, it results in scenarios where one daughter cell receives all of the chromosomes while the other daughter cell receives none. This is significant because it leads to gametes that are either diploid (containing two copies of each chromosome) or aneuploid (missing a chromosome).

If fertilization occurs with these gametes, it can result in offspring with an abnormal number of chromosomes. This condition is the basis of several genetic disorders and can lead to complications such as Down syndrome, which is a result of having three copies of chromosome 21, known as trisomy. Therefore, the process clearly supports that one cell ends up with a complete set, while the other cell is devoid of chromosomes, making this the correct understanding of total non-disjunction during meiosis.