Chapter 12: The Cell Cycle

Merged flashcards from Chapter 12 of Pearson's Campbell Biology, Twelfth Edition.

Interphase

Phase of the cell cycle in which the cell grows in preparation for cell division

• Chromosomes are duplicated

• Genetic material is copied precisely

Mitosis

Phase of the cell cycle where the chromosome copies from interphase are separated from each other and moved to opposite ends of the cell

Cytokinesis

Phrase of the cell cycle where the cell divides into two daughter cells, genetically identical to each other and the parent cell

• Daugher cells may go on to divide after interphase, restarting the cell cycle

Cell division

The reproduction of cells to ensure the continuity of life

• Is the characteristic that distinguishes living things from nonliving matter

• Seen in:

  • Single-celled organisms giving rise to new organisms

  • Multicellular eukaryotes undergoing embryonic division as well as renewal and repair for the fully grown

Genetic material (DNA)

Instructions for the cell’s function within a eukaryote’s nucelus or prokaryote’s interior

• Cell division is remarkably accurate in passing this from one generation to the next

Genome

All the DNA within a cell

• Consists of a single DNA molecule (common for prokaryotes) or a number of DNA molecules (common in eukaryotes)

Chromosome

The packaging form for DNA molecules in a eukaryotic cell

• Carries several hundred to a few thousand genes

• Every eukaryotic species has a characteristic number of these in each cell nucleus

Chromatin

A complex of DNA and protein that condenses during cell division in eukaryotic chromosomes

Somatic cells (nonreproductive cells)

Cells that have two sets of chromosomes

Gametes (reproductive cells)

Cells that have half as many chromosomes as somatic cells

• Produced by a variation of cell division called meiosis

Sister chromatids

Joined copies of the original chromosome created during DNA replication in preparation for cell division

• These separate and move into two nuclei during cell division, thus turning into chromosomes

Centromere

The narrow “waist” of the duplicated chromosome where the two chromatids are most closely attached

Meiosis

The variation of cell division that creates gametes

• Yields nonidentical daughter cells with half as many chromosomes as the parent cell

Walther Flemming

The German anatomist who developed dyes to observe chromosomes during mitosis and cytokinesis in 1882

Cell cycle

Consists of:

• The mitotic (M) phase (mitosis and cytokinesis)

• Interphase (cell growth and copying of chromosomes in preparation for cell division)

Mitotic phase

Phase of the cell cycle that includes mitosis and cytokinesis

Divided into five stages:

• Prophase

• Prometaphase

• Metaphase

• Anaphase

• Telophase

Interphase

Phase of the cell cycle where cell growth and chromosome duplication occurs in preparation for cell division

Divided into three phases:

• G₁ phase (first gap)

• S phase (synthesis)

• G₂ phase (second gap)

G₁ phase

Phase of interphase where metabolic activity and growth occurs

S phase

Phase of interphase where chromosomes are duplicated

G₂ phase

Phase of interphase where metabolic activity, growth, and preparation for cell division occurs

Prophase

Phase of mitosis where sister chromatids joined by a centromere become visible as the mitotic spindle develops

Prometaphase

Phase of mitosis where the nuclear envelope dissolves and kinetochore microtubules extend over the chromosomes

• Centrosomes are at opposite ends of the cell by the time of this phase’s completion

Metaphase

Phase of mitosis where the mitotic spindle is developed with centrosomes at the pole and centered chromosomes

Anaphase

Phase of mitosis where daughter chromosomes are pulled apart towards the poles of the cell by centrosomes

Telophase

Phase of mitosis where cytokinesis starts to occur as the nucleus reforms and the cell divides

Mitotic spindle

A structure made of microtubules that controls chromosome movement during mitosis

Centrosome

An assembly of spindle microtubules at the poles of each cell for organization

• Replicates during interphase and migrates during prophase and prometaphase

Kinetochore

A protein complex associated with centromeres, assigned to each sister chromatid

• Spindle microtubules attach to these during prometaphase

Metaphase plate

Plane midway between the spindle’s two poles where the chromosomes are all lined up

Cleavage

Process that causes cytokinesis in animal cells

Cleavage furrow

The first sign of cleavage in an animal cell, marked as a shallow groove in the cell surface near the old metaphase plate

Cell plate

Sign of cytokinesis in plant cells after cell division

Binary fission

The type of cell division conducted by prokaryotes such as bacteria and archaea

• Replicates the chromosome, then actively moves them apart as the plasma membrane pinches inward for division

• Likely the basis for mitosis in eukaryotes through evolution