topic 7 cell cycle

Process by which a cell reproduces into new daughter cells.

cell division

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 cells

cell cycle

The genetic material of an organism or virus

genome

A cellular structure composed of one long DNA molecule (found in prokaryotes - one set- and eukaryotes - two sets)

chromosome

Complex of DNA and proteins that makes up eukaryotic chromosomes and is in a dispersed form when the cell is not dividing.

chromatin

Any cell in a multicellular organism that is not a germ cell.

somatic cell

Haploid reproductive cells that unite during sexual reproduction to produce a diploid zygote.

gamete

Two copies of a duplicated chromosome attached to each other by proteins at the centromere.

sister chromatids

The region on each sister chromatid where they are most closely attached to each other by proteins.

centromere

Nuclear division in eukaryotic cells that maintains chromosome number by equally distributing replicated chromosomes to daughter cells.

mitosis

The division of the cytoplasm to form two separate daughter cells.

cytokinesis

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

mitotic (M) phase

The period in the cell cycle when the cell is not dividing.

interphase

Phase of interphase when the cell grows and performs its tasks.

G1 phase

Part of interphase in which DNA is replicated.

S phase

Part of interphase after DNA synthesis when the cell prepares for division.

G2 phase

stage of mitosis when chromatin condenses into chromosomes, mitotic spindle forms, and nuclear envelope fragments.

prophase

Stage of mitosis where the chromosomes are aligned in middle of cell

metaphase

Stage of mitosis where chromatids separate and move to opposite poles of the cell.

anaphase

Stage of mitosis where nuclear membranes reform, chromosomes uncoil, and cytokinesis begins.

telophase

Microtubules and associated proteins that are involved in moving the chromosomes during mitosis.

mitotic spindle

A structure present in the cytoplasm of animal cells that is a microtubule-organizing center during cell division.

centrosome

A radial array of short microtubules that extend from each centrosome toward the plasma membrane in animal cells undergoing mitosis.

aster

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

kinetochore

A plane midway between the two poles of a cell along which the centromeres of all the duplicated chromosomes line up.

metaphase plate

The pinching of the plasma membrane in animal cells.

cleavage

The first sign of cleavage in an animal cell in which a shallow groove forms in the cell surface near the former metaphase plate.

cleavage furrow

A membrane-bound group of flattened sacs located at the midline of a dividing plant cell, inside which the new cell wall forms.

cell plate

The method for cell division in prokaryotes.

binary fission

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

cell cycle control system

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

checkpoint

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

G0 phase

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

cyclin

A protein kinase that is only active when attached to a particular cyclin.

cyclin-dependent kinase

A protein complex made of cyclin and cyclin-dependent kinase required for a cell to progress from late interphase to mitosis.

MPF (Maturation promoting factor)

A protein released by certain cells to stimulate other cells to divide.

growth factor

A mechanism that stops cell division when cells get overcrowded.

density-dependent inhibition

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

anchorage dependence

The process that turns a normal cell into a cancerous cell.

transformation

A mass of abnormal cells that are not capable of surviving away from the tumor's origin.

benign tumor

A cancerous tumor containing abnormal cells that are capable of invading and surviving in new sites.

malignant tumor

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

metastasis