Question

Which event during meiosis leads to a reduction in chromosome number from 2n to n

Answer 1

Answer:

The old name for meiosis was reduction/ division. Meiosis I reduces the ploidy level from 2n to n (reduction) while Meiosis II divides the remaining set of chromosomes in a mitosis-like process (division). Most of the differences between the processes occur during Meiosis I. Hope this helps :)

Answer 2

Answer:

The question lacks options, the options are:

a) Pairs of homologous chromosomes line up at equator

b) DNA undergoes replication

c) Homologous chromosomes travel to opposite sides of the cell

d) Sister chromatids are pulled apart at the centromere

The answer is C

Explanation:

Meiosis is that type of cellular division that results in daughter cells with a reduced number of chromosomes (by half) i.e. from a diploid to haploid state. In order for this reduction to occur, meiosis occurs in a two-step division process viz: meiosis I and meiosis II

In meiosis I, the homologous chromosomes (similar but non-identical chromosomes received from each parent) pair up during prophase. The homologous chromosomes are later separated into opposite sides of the cell by spindle microtubules in the ANAPHASE stage. This causes the chromosomal number to reduce. For example, 46 chromosomes in humans are separated into opposite poles in ANAPHASE stage to have 23 chromosomes on each side.

This has reduced the diploid state of 2n=46 to n=23.

Meiosis II, specifically anaphase II, is when sister chromatids (replicated chromosome) separate. Each separated chromatid becomes an individual chromosome after separation.