BIO 103 - CH12 VOCAB - How Cells Divide

Diploid

This type of cell (ploidy level) contains two sets of chromosomes (2n), one set inherited from each parent

Anaphase

The fourth stage of mitosis, in which the chromatids of each chromosome have separated, and the daughter chromosome are moving to the poles of the cell

Telophase

The filth and final stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun

Chromatin

The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, this exists in its dispersed form, as a mass of very long, thin, fibers that are not visible with a light microscope

Haploid

This type of cell (ploidy level) contains only one set of chromosomes (n)

Interphase

The period in the cell cycle when the cell is not dividing. During this phase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. It often accounts for about 90% of the cell cycle.

Cytokinesis

The division of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II.

Gamete

A haploid reproductive cell, such as an egg or sperm, that is formed by meiosis or is the descendant of cells formed by meiosis. These cells (sperm and egg) unite during sexual reproduction to produce a diploid zygote.

Meiosis

A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosomes sets as the original cell.

Somatic Cell

Any cell in a multicellular organism except a sperm or egg or their precursors

Deoxyribonucleic acid

A nucleic acid molecule, usually a double-stranded helix, in which each polynucleotide strand consists of nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T); capable of being replicated and determining the inherited structure of a cell's proteins

Genome

The genetic material of an organism or virus; the complete complement of an organism's or virus's genes along with its noncoding nucleic acid sequences.

Chromosome

A cellular structure consisting of one DNA molecule and associated protein molecules. A duplicated chromosome has two DNA molecules. (In some contexts, such as genome sequencing, the term may refer to the DNA alone.) A eukaryotic cell typically has multiple, linear chromosomes, which are located in the nucleus. A prokaryotic cell often has a single, circular chromosome, which is found in the nucleoid, a region that is not enclosed by a membrane.

Sister Chromatids

Two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms. While joined, these make up one chromosome. They are eventually separated during mitosis or meiosis II

Centromere

In a duplicated chromosome, the region on each sister chromatid where it is most closely attached to its sister chromatid by proteins that bind to the centromeric DNA. Other proteins condense the chromatin in that region, so it appears as a narrow "waist" on the duplicated chromosome. (An unduplicated chromosome has a single one of these, identified by the proteins bound there.)

Daughter Cell

Either of the two cells formed when a cell undergoes cell division by cytokinesis (preceded by mitosis or meiosis I/II).

Mitotic Spindle

An assemblage of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis.

Checkpoint

A control point in the cell cycle where stop and go-ahead signals can regulate the cycle

Cell Cycle

An ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into two. In eukaryotes, it is composed of interphase (including G1, S, and G2 phases) and M phase (including mitosis and cytokinesis).

G1 Phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

G2 Phase

The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

G0 Phase

A non-dividing state occupied by cells that have left the cell cycle, sometimes reversibly.

S Phase

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

M Phase

The phase of the cell cycle that includes mitosis and cytokinesis.

Prophase

The first stage of mitosis, in which the chromatin condenses into discrete chromosomes visible with a light microscope, the mitotic spindle begins to form, and the nucleolus disappears but the nucleus remains intact.

Metaphase

The third stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate.

Growth Factor

(1) A protein that must be present in the extracellular environment (culture medium or animal body) for the growth and normal development of certain types of cells.
(2) A local regulator that acts on nearby cells to stimulate cell proliferation and differentiation.

Density-dependent inhibition

A phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another.

Anchorage Dependence

The requirement that a cell must be attached to a substratum in order to initiate cell division.

Benign Tumor

A mass of abnormal cells with specific genetic and cellular changes such that the cells are not capable of surviving at a new site and generally remain at the site of the tumor's origin

Cell Division

Simply, the reproduction of cells... in humans, can involve mitosis (produce more somatic cells) or meiosis (gamete production) followed by cytokinesis.

Mitosis

A process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. This process conserves the number of chromosomes by allocated replicated chromosomes equally to each of the daughter nuclei.

Binary Fission

A method of asexual reproduction in single-celled organisms in which the cell grows to roughly double its size and then divides into two cells. In prokaryotes, it does not involve mitosis, but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process.

Malignant Tumor

A cancerous tumor containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new sites. They can impair the functions of one or more organs.