Question

The term meiotic __________________ refers to the failure of chromosomes to separate normally during meiosis. This results in haploid cells that have too many or too few chromosomes

Answer 1

Nondisjunction is the failure of chromosomes to separate during meiosis, leading to gametes with abnormal numbers of chromosomes and resulting in conditions like Down syndrome.

Step-by-step explanation:

The term meiotic nondisjunction refers to the failure of chromosomes to separate normally during meiosis. Such an event leads to the production of gametes that have abnormal chromosome numbers, potentially resulting in medical conditions such as Down syndrome. Nondisjunction can occur during two distinct phases of meiosis:

• Meiosis I: Here, if homologous chromosomes fail to separate, the result is two gametes with an extra chromosome (n + 1) and two gametes with a missing chromosome (n - 1).
• Meiosis II: If sister chromatids fail to separate during this phase, it results in one gamete with an extra chromosome (n + 1), one gamete with a missing chromosome (n - 1), and two gametes with the expected number of chromosomes (n).

Thus, nondisjunction contributes to aneuploidy, which describes the presence of an abnormal number of chromosomes in a cell.