Biology Campbell Chapter 12 Def. And Concepts

Front 1

Cell Division

Back 1

The continuity of life based on the reproduction of cells.

Front 2

Cell Cycle

Back 2

The life of a cell from the time it is first formed from a dividing parent cell until its own division into two cells.

Front 3

Genome

Back 3

A cell's endowment of DNA, its genetic information.

Front 4

Chromosomes

Back 4

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.

Front 5

Somatic Cells

Back 5

Any cell in a multicellular organism except a sperm and egg.

Front 6

Gametes

Back 6

Reproductive cells (sperm and egg) that have half as many chromosomes as somatic cells.

Front 7

Chromatin

Back 7

Eukaryotic chromosomes are made of a complex of DNA and associated proteins molecules.

Front 8

Sister Chromatid

Back 8

Either of two copiesof a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms. While joined, two sister chromatids make up one chromosome; chromatids are eventually separated during mitosis and meiosis.

Front 9

Cohesins

Back 9

Adhesive protein complexes

Front 10

Sister Chromatid Cohesion

Back 10

Two chromatids, each containing an identical DNA molecule, are initially attached all along their lengths by adhesive protein complexes.

Front 11

Centromere

Back 11

A specialized region where the two chromatids are most closely attached.

Front 12

Arm

Back 12

The part of of a chromatid on either side of the centromere.

Front 13

Mitosis

Back 13

The division of the nucleus.

Front 14

Cytokinesis

Back 14

The division of the cytoplasm.

Front 15

Meiosis

Back 15

Yields nonidentical daughter cells that have only one set of chromosomes, thus half as many chromosomes as the parent cell.

Front 16

Mitotic (M) Phase

Back 16

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

Front 17

Interphase

Back 17

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 accounts for 90% of the cell cycle.

Front 18

G₁Phase
"first gap"

Back 18

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

Front 19

S Phase
"synthesis"

Back 19

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

Front 20

G₂Phase
"second gap"

Back 20

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

Front 21

Five Stages of Mitosis

Back 21

Prophase, prometaphase, metaphase, anaphase, and telophase.

Front 22

Prophase

Back 22

The first stage of mitosis, in which the chromatin condenses, the mitotic spindle begins to form, and the nucleolus disappears, but the nucleus remains intact.

Front 23

Prometaphase

Back 23

The second stage of mitosis, in which discrete chromosomes consisting of identical sister chromatids appear, the nuclear envelope fragments, and the spindle microtubules attach to the kinetochores of the chromosomes.

Front 24

Metaphase

Back 24

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.

Front 25

Anaphase

Back 25

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

Front 26

Telophase

Back 26

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

Front 27

Mitotic Spindle

Back 27

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

Front 28

Centrosome

Back 28

Structure present in the cytoplasm of animal cells, important during cell division; functions as a microtubule-organizing center. A centrosome has two centrioles.