Cell Division and Mitosis

Flashcards covering key concepts related to cell division, mitosis, and cytokinesis.

What are the two stages of cell division?

Karyokinesis and Cytokinesis.

What is karyokinesis?

The division of the nucleus.

What is cytokinesis?

The division of the cytoplasm.

What are the two types of cells in an organism's body?

Somatic cells and reproductive cells (gametes).

What type of cells are produced through mitosis?

Somatic cells.

What is the diploid number of chromosomes in human somatic cells?

2n = 46

What type of cells are produced through meiosis?

Gametes (reproductive cells).

What is the haploid number of chromosomes in human gametes?

n = 23

What are homologous chromosomes?

A pair of chromosomes with the same structural characteristics, one from the male parent and one from the female parent.

What does the cell cycle refer to?

The sequence of events that involves DNA multiplication and cell division to produce two daughter cells.

What are the two main phases of the cell cycle?

Interphase and M phase.

What are the phases of interphase?

G1 phase, S phase, and G2 phase.

What happens during the S phase of interphase?

DNA synthesis occurs, and each chromosome multiplies into two identical sister chromatids.

What is mitosis?

The division of the nucleus of a parent cell into two nuclei, each containing the same number of chromosomes and genetic content as the parent cell.

What are the phases of mitosis?

Prophase, metaphase, anaphase, and telophase.

What happens during prophase?

Chromatin condenses into chromosomes, the nuclear membrane disintegrates, the nucleolus disappears, centrioles move to opposite poles, and spindle fibers start to form.

What happens during metaphase?

Chromosomes align in a single row on the equatorial plane, maintained by spindle fibers connected to the centrioles at opposite poles.

What happens during anaphase?

The centromere divides, sister chromatids separate, and spindle fibers shorten to pull the sister chromatids to opposite poles.

What happens during telophase?

Chromatids (now daughter chromosomes) arrive at opposite poles, chromosomes revert to fine chromatin threads, nucleoli reform, spindle fibers disappear, and a new nuclear membrane forms.

What is cytokinesis?

The division of the cytoplasm that occurs immediately after the nucleus is formed (at the end of telophase).

Describe cytokinesis in animal cells.

The plasma membrane constricts in the middle of the cell between the two nuclei due to contracting microfilaments, eventually splitting the cell into two daughter cells.

Describe cytokinesis in plant cells.

Vesicles combine to form cell plates at the center of the cell, which expand outwards until they combine with the plasma membranes. Cellulose fibers strengthen the new cell walls, forming two daughter cells.

Give three examples of the necessity of mitosis.

Embryo development, organism growth, regeneration (e.g., lizard growing a new tail), and repairing injuries by replacing dead or damaged cells.