Steps of the Cell Cycle and Vocab

malignant tumor

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

haploid cell

A cell containing only one set of chromosomes (n).

diploid cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

Cyclin

A cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle.

Chromosomes

A cellular structure carrying genetic material, found in the nucleus of eukaryotic cells. Each chromosome consists of one very long DNA molecule and associated proteins

Checkpoint

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

What are the five stages of mitosis?

PPMAT Prophase Prometaphase Metaphase Anaphase Telophase

MPF

Maturation-promoting factor (or M-phase-promoting factor); a protein complex required for a cell to progress from late interphase (G2) to mitosis. The active form consists of cyclin and a cyclin dependent kinase.

Meiosis

Meiosis is essential to sex, because it enables each parent to contribute one set of chromosomes-- half the total-- to each diploid offspring.

origin of replication

Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides. Prokaryotic DNA has only one while eukaryotic DNA has many.

G2 Phase

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

Prometaphase

The second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes.

Metastasis

The spread of cancer cells to locations distant from their original site.

S Phase

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

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.

How many chromatids are in a duplicated chromosome?

2

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.

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.

Transformation

(1) The conversion of a normal animal cell to a cancerous cell. (2) A change in genotype and phenotype due to the assimilation of external DNA by a cell. When the external DNA is from a member of a different species, transformation results in horizontal gene transfer

transformation

(1) The conversion of a normal animal cell to a cancerous cell. (2) A change in genotype and phenotype due to the assimilation of external DNA by a cell. When the external DNA is from a member of a different species, transformation results in horizontal gene transfer.

cleavage

(1) The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane. (2) The succession of rapid cell divisions without significant growth during early embryonic development that converts the zygote to a ball of cells.

Cell cycle control system

A cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle.

Gametes

A haploid reproductive cell, such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote.

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 Plate

A membrane-bounded, flattened sac located at the midline of a dividing plant cell, inside which the new cell wall forms during cytokinesis.

Binary Fission

A method of asexual reproduction by "division in half." In prokaryotes, binary fission does not involve mitosis, but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process.

binary fission

A method of asexual reproduction by "division in half." In prokaryotes, binary fission does not involve mitosis, but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process.

G0 Phase

A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.

Mitosis

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

Cyclin-dependent kinases

A protein kinase that is active only when attached to a particular cyclin. When its cyclin is attached together they form the maturation promoting factor (MPF).

aster

A radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis.

kinetochore

A structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle.

Centrosome

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.

sexual reproduction

A type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the two parents.

asexual reproduction

A type of reproduction involving only one parent that produces genetically identical offspring by budding or by the division of a single cell or the entire organism into two or more parts.

mitotic spindle

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

Metaphase Plate

An imaginary structure located at a plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located.

Metaphase plate

An imaginary structure located at a plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located.

Cell Cycle

An ordered sequence of events in the life of a cell

Somatic Cells

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

somatic cell

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

Centromere

In a duplicated chromosome, the region on each sister chromatid where they are most closely attached to each other by proteins that bind to specific DNA sequences; this close attachment causes a constriction in the condensed chromosome. (An uncondensed, unduplicated chromosome has a single centromere, identified by its DNA sequence.)

Chromatin

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

Cytokinesis

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

Telophase

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

G1 Phase

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

Cleavage Furrow

The first sign of cleavage in an animal cell; a shallow groove around the cell in the cell surface near the old metaphase plate.

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.

Anaphase

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

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 sequence

interphase

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

mitotic (M) phase

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

Density Dependent Inhibition

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

density-dependent inhibition

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

Cell Division

The reproduction of cells

Anchorage Dependence

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

anchorage dependence

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

Sister Chromatids

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