During metaphase, chromosomes align along the metaphase plate, in preparation for anaphase. This phase of the cell cycle is highly visible as a distinct band of chromosomes lined up in the center of the cell.

Mitosis and meiosis are similar processes that yield very different results. One of the major differences is that meiosis separates homologous chromosomes prior to separating sister chromatids. This is what leads to the reduction of ploidy. Both processes involve spindle formation (the microtubule apparatus that pulls the chromosomes/chromatids apart). Recombination is a phenomenon unique to meiosis that results in increasing genetic diversity.

The main differences between meiosis and mitosis are that, during meiosis I, there is recombination between homologous chromosomes and the separation of homologous chromosomes. During mitosis, homologous chromosomes are not separated, only the sister chromatids. Both processes involve the breakdown of the nuclear envelope, allowing DNA to enter the cytoplasm and align at the equatorial plate and both processes involve separation of sister chromatids.

Only meiosis involves separation of homologous chromosomes. Since the question asks for an event exclusive to mitosis, none of these answers are suitable.

This is a simple memorization problem. Crossover occurs when the nucleus decondenses. The chromosomes are able to crossover during prophase I when chromosome pairs are aligned next to one another. Crossover cannot occur later in meiosis, as the chromosomes have already been separated.

There are four main phases in mitosis: prophase, metaphase, anaphase, and telophase. Prophase involves nuclear membrane breakdown, formation of mitotic spindle, and disappearance of nucleolus. Recall that nucleolus is the site of ribosome synthesis; therefore, cell A is in prophase. The question states that the nuclear contents are spilling out in Cell B. Nuclear membrane holds the contents of nucleus in place. During prophase, this nuclear membrane breaks down, causing the contents of the nucleus (like chromosomes) to spill out into the cytoplasm.

Metaphase involves the alignment of the chromosomes (with sister chromatids) along the equatorial line of the cell. In anaphase, the aligned chromosomes are pulled towards the opposite ends of the cell, causing the sister chromatids to separate. Finally, in telophase two distinct cell start appearing with chromosomes that have no sister chromatids; therefore, cell C must be in telophase.

Mitosis is immediately followed by cytokinesis, during which the cytoplasm is divided equally between the two daughter cells.

The key difference between sexual and asexual reproduction is recombination. If a process involves shuffling of genetic material between chromosomes (recombination), then it is sexual reproduction. Recall that crossing over, a type of genetic recombination, occurs during prophase I of meiosis. This leads to the production of daughter cells that are distinct from the parents; therefore, meiosis is a form of sexual reproduction.

In mitosis there is no genetic recombination and the daughter cells are identical to the parent cells; therefore, mitosis is a form of asexual reproduction.

This cell is in metaphase. This can be determined because the chromosomes are lined up on in the middle. This is known as the metaphase plate. After alignment the microtubules attach, and the chromosomes are ready to be seperated, which is the next phase (anaphase).

During mitosis, the nuclear envelope breaks down to allow the formation of chromosomes. Since all concentration gradients are dependent upon the impermeability of a membrane, when this envelope breaks down, the concentration gradient weakens and disappears.

Mitosis and meiosis are both processes that involve cell division. In mitosis, a diploid parent cell divides and gives rise to two identical, diploid daughter cells. In meiosis, a diploid parent cell divides and gives rise to four identical, haploid daughter cells. Meiosis is divided into meiosis I and meiosis II. Meiosis I is unique because its prophase (prophase I) involves exchange of genetic material between chromosomes. This process is called recombination. Meiosis II is similar to mitosis. Note that both meiosis I and II have prophase, metaphase, anaphase, and telophase.

Metaphase in both mitosis and meiosis involves the alignment of the cell’s nuclear material along the midline. In mitosis, sister chromatids line along the midline. This means that in humans there will be a total of 46 columns of chromosomes along the midline (46 chromosomes with their respective sister chromatids). In meiosis I, however, it is slightly different. Recall that prophase I involves tetrad formation. This means that homologous chromosomes (with their respective sister chromatids) pair up along the midline, reducing the amount of columns of chromosomes in metaphase I to half of metaphase in mitosis. This means that in humans there will be only 23 columns of chromosomes in metaphase I.

Ploidy number refers to the amount of homologous chromosomes present. In humans, there are two sets of homologous chromosomes; therefore, humans are diploid. As mentioned mitosis produces two identical, diploid daughter cells (each cell has homologous chromosomes). In meiosis I two identical, haploid daughter cells are produced. These daughter cells have 23 chromosomes with sister chromatids; however, they lack their homologous pair and are, therefore, haploid. These two daughter cells undergo meiosis II and produce the final products of meiosis, which are four haploid daughter cells. Remember that the daughter cells of meiosis II will not have a sister chromatid because the sister chromatids are pulled to opposite poles during anaphase II.

Humans are diploid organisms with a total of 46 chromosomes (2n = 46). They have 23 distinct chromosomes and each chromosome has a homologous chromosome, giving a total of 46 chromosomes. Upon completion of DNA replication in S phase, each chromosome gains an identical sister chromatid that is joined to the original chromosome at the centromere; however, this whole entity is still considered a single chromosome. When a cell enters prophase of mitosis, there are a total of 46 chromosomes, each with a sister chromatid. In metaphase, the cell still has 46 chromosomes and these chromosomes align along the midline of the cell. In anaphase, the sister chromatids get pulled apart to opposite ends; therefore, the sister chromatid separates from the chromosome and becomes its own chromosome. This means that in anaphase there are a total of 92 chromosomes in the cell.

These 92 chromosomes get pulled to opposite ends where 2 new daughter cells (with 46 chromosomes and no sister chromatids) are produced.