During metaphase, the chromosomes of the cell are __________.

Which of the following processes occur in meiosis but do not occur in mitosis?

I. Spindle formation

II. Separation of homologous chromosomes

III. Separation of sister chromatids

IV. Recombination

Which of the following occurs in mitosis, but does not occur in meiosis?

When does genetic crossover occur during meiosis?

Meiosis is a form of cell division that occurs in special types of cells called germ cells. It is different from mitosis because it takes a diploid cell and splits it into four, nonidentical haploid cells. In males, these haploid cells are called sperm and in females they are called eggs or ova. Meiosis has two steps: meiosis I and meiosis II. Both steps have their corresponding prophase, metaphase, anaphase, and telophase. Meiosis I phases are similar to mitotic phases, with a few key differences. Meiosis II phases are exactly identical to the mitotic phases.

A student is observing a set of cells under the microscope. He takes notes but forgets to write the mitotic phase for each slide. His notes are as follows.

Cell A: Site of ribosome synthesis disappears

Cell B: The nuclear content spills out into the cytoplasm

Cell C: No sister chromatids are visible

What is the mitotic phase of each cell?

Cellular division is an essential part of the cell cycle. When a cell divides it passes genetic information to daughter cells. The amount of genetic information passed on to daughter cells depends on whether the cell undergoes mitosis or meiosis. Mitosis is the most common form of cell division. All somatic cells undergo mitosis, whereas only germ cells undergo meiosis. Meiosis is very important because it produces gametes (sperm and eggs) that are required for sexual reproduction. Human germ cells have 46 chromosomes (2n = 46) and undergo meiosis to produce four haploid daughter cells (gametes).

Meiosis is a form of __________ reproduction and mitosis is a form of __________ reproduction.

Which stage of mitosis is shown in the illustration?

Meiosis is a form of cell division that occurs in special types of cells called germ cells. It is different from mitosis because it takes a diploid cell and splits it into four, nonidentical haploid cells. In males, these haploid cells are called sperm and in females they are called eggs or ova. Meiosis has two steps: meiosis I and meiosis II. Both steps have their corresponding prophase, metaphase, anaphase, and telophase. Meiosis I phases are similar to mitotic phases, with a few key differences. Meiosis II phases are exactly identical to the mitotic phases.

In humans, a cell in prophase has __________ chromosomes, in metaphase has __________ chromosomes, and in anaphase has __________ chromosomes.

Meiosis is a form of cell division that occurs in special types of cells called germ cells. It is different from mitosis because it takes a diploid cell and splits it into four, nonidentical haploid cells. In males, these haploid cells are called sperm and in females they are called eggs or ova. Meiosis has two steps: meiosis I and meiosis II. Both steps have their corresponding prophase, metaphase, anaphase, and telophase. Meiosis I phases are similar to mitotic phases, with a few key differences. Meiosis II phases are exactly identical to the mitotic phases.

Which of the following is true regarding meiosis and mitosis?

I. Prophase I of meiosis and prophase of mitosis both involve recombination

II. In humans, cells in metaphase of mitosis will have twice as many columns of chromosomes as cells in metaphase I

III. The daughter cells of mitosis have similar ploidy number as daughter cells of meiosis I

Nuclear transport is a very important concept of study in modern cellular biology. Transport of proteins into the nucleus of an organism requires energy in the form of GTP, which is attached to a protein called Ras-related Nuclear protein (RAN).

RAN is a monomeric G protein found in both the cytosol as well as the nucleus and its phosphorylation state plays an important role in the movement of proteins into and out of the nucleus. Specifically, RAN-GTP and RAN-GDP binds to nuclear import and export receptors and carries them into or out of the nucleus. They also play a role in dropping off cargo that import and export receptors hold onto. RAN's functions are controlled by two other proteins: RAN guanine exchange factor (RAN-GEF) and RAN GTPase activating protein (GAP). RAN-GEF binds a GTP onto RAN, while RAN-GAP hydrolyzes GTP into GDP. As a result, there is a RAN-GTP and RAN-GDP concentration gradient that forms between the cytosol and nucleus.

During prophase, what most likely happens to the RAN-GTP and RAN-GDP concentration gradient?