Meiosis I involves the separation of homologous chromosomes, while meiosis II involves the separation of sister chromatids. The G2 phase precedes meiosis I or mitosis, but does no precede meiosis II. Interkinesis is the period that separates meiosis I and meiosis II.

Meiosis I results in two daughter cells, each with only one copy of each chromosome, from a parent cell with two copies of each chromosome. The parent cell is diploid, while the daughter cells are haploid. This is known as reductional division because the daughter cell contain less genetic material than the parent cell. Meiosis II results in four daughter cells from two parent cells. Each parent contains one copy of each chromosome, and each daughter cell also contains one copy of each chromosome (although the material is stored on a single chromatid). Since both parent and daughter cells contain the same amount of genetic information, this is considered an equational division. The daughter cells of both meiosis I and meiosis II contain only one copy of each chromosome, as homologous pairs have been separated. Both meiosis products are thus considered haploid, making this the correct answer.

For this question you have to carefully track the chromosomes through meiosis. A human cell in metaphase I will have formed the tetrads and would have aligned the genetic material along the metaphase plate. The sister chromatids are still attached to one another, so they only count as one chromosome per pair of chromatids. There are a total of 46 chromosomes in metaphase I, each comprised of two sister chromatids. There are 23 homologous pairs, each containing two complete chromosomes.

During telophase II, the cell is in a haploid state. The homologous pairs have been separated during anaphase I, such that each cell contains 23 complete chromosomes. Each chromosome is then broken into its chromatids, such that the total number of chromosomes represented during anaphase II is 46, with each chromatid representing a chromosome. If each of the chromosomes still had its sister chromatid, then the total number of chromosomes would be 23. Telophase II follows anaphase II. The 46 chromatids are sequestered to opposite sides of the cell, but the cell has not yet divided. A cell in telophase II is haploid, containing only one copy of each homologous chromosome, but contains two chromatids for each copy. The total number of chromosomes in a telophase II cell is thus 46. As soon as the cell completes cytokinesis, and two daughter cells are formed, they become haploid cells with 23 chromosomes each.

In most vertebrates, sperm cells join with egg cells to form a zygote. Each cell produces a haploid complement of chromosomes in order to form the zygote. The result is a new organism with a full set of maternal chromosomes and a full set of paternal chromosomes.

When a sperm joins with an egg, only the nucleus of the sperm enters to egg to form the zygote. The nuclear envelope is then altered, allowing the paternal DNA to intermix with the maternal DNA in the zygote nucleus. The sperm does not contribute a nucleus (only genetic material), cytoplasm, or diploid copies of any chromosome.

Reductional division of cells occurs during meiosis. This means that the number of chromosomes in the cells undergoing meiosis is reduced by half, as compared to the parental cells. The cells that arise from meiosis are genetically unique from their parental cells, since they do not retain the same genetic information.

The cells that result from meiosis are haploid, carrying only half of the normal DNA present in somatic cells.

Crossing over, or recombination, is a phenomenon in which small parts of homologous chromosomes move from one copy of the chromosome to the other. This process helps promote genetic diversity by providing slightly different copies of chromosomes for offspring.

Inducing genetic mutations would be a way to increase diversity, but it is not something that actually happens during meiosis. Condensation of chromosomes and separation of sister chromatids occur during both mitosis and meiosis, and do not promote genetic diversity.

In meiosis I the cell separates homologous chromosomes. In meiosis II the cell separates sister chromatids. In general, meiosis I and II are similar processes that go through the same steps (prophase, metaphase, etc.) with only a few key difference. During metaphase I, homologous chromosomes line up in tetrads. During metaphase II, chromosomes line up singularly. Crossing over can only occur during the formation of tetrads, and cannot occur during meiosis II.

Germ cells are diploid stem cells that give rise to the gametes of organisms that reproduce sexually. These cells can undergo both meiosis and mitosis. Mitosis is used to duplicate the germ cell, while meiosis is used to generate gametes.

Somatic cells are found in all other regions of the body, and are only capable of mitosis.

Crossing over occurs during prophase I of meiosis I. Crossing over is the physical exchange of chromosome parts, resulting in recombinant chromosomes and increased genetic variability. In order for this to occur, there is a requirement that the two homologous chromosomes be aligned next to one another, which occurs in prophase I of meiosis during tetrad formation.

Prophase I is the correct answer. During oogenesis in mammals, meiosis I occurs during the prenatal age. When the germ cells reach prophase I, the cell cycle is arrested, and the cells are frozen in prophase until puberty.

During puberty, the female will begin to ovulate. This means that one egg cell will progress from prophase I to metaphase I and complete meiosis on a cyclical basis, known as the menstrual cycle.

Down Syndrome results from trisomy 21, in which an individual has three copies of chromosome 21 in their genome. The cause for the extra chromosome is a nondisjunction event, resulting in an uneven splitting of the genome during meiosis.

Nondisjunction mainly occurs during meiosis I, particularly during anaphase I when homologous chromosomes are separated. When both chromosomes are pulled to the same pole the result of meiosis I is two cells, one with 22 chromosomes and one with 24. Meiosis II is used to segregate the sister chromatids of these cells, but does not change the amount of genetic material. When a gamete with 24 chromosomes fuses with a normal gamete with 23 chromosomes, the result is trisomy. When the trisomy particularly affects chromosome 21, the result is Down Syndrome.