09 Cell Cycle

Cell Division

The process by which a parent cell divides into two or more daughter cells.

Cell Cycle

The life of a cell from its formation until it divides.

Genome

The complete set of genetic material in an organism.

Chromatin

A complex of DNA and protein found in eukaryotic cells.

Chromosomes

Structures that carry genetic information, made of chromatin.

Sister Chromatids

Identical copies of a chromosome, joined together at the centromere.

Centromere

The region where two sister chromatids are most closely attached.

Mitosis

The division of the genetic material in the nucleus.

Cytokinesis

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

Meiosis

A type of cell division that produces nonidentical daughter cells with half the number of chromosomes.

Interphase

The phase of the cell cycle where the cell grows and prepares for division.

G1 phase

The 'first gap' phase of interphase where the cell grows and carries out normal functions.

S phase

The 'synthesis' phase of interphase where DNA is replicated.

G2 phase

The 'second gap' phase of interphase where the cell prepares for mitosis.

Prophase

The first stage of mitosis where chromatin condenses into visible chromosomes.

Prometaphase

The stage of mitosis where the nuclear envelope fragments and microtubules attach to kinetochores.

Metaphase

The stage of mitosis where chromosomes align at the metaphase plate.

Anaphase

The stage of mitosis where sister chromatids separate and move toward opposite poles.

Telophase

The final stage of mitosis where the chromosomes decondense and nuclear envelopes reform.

Binary Fission

A method of asexual reproduction in prokaryotes where a single cell divides into two.

Cleavage Furrow

The indentation of the cell's surface that begins the process of cytokinesis in animal cells.

Cell Plate

A structure that forms during cytokinesis in plant cells, leading to the formation of a new cell wall.

Checkpoints

Regulatory points in the cell cycle that control progression through the cycle.

G1 checkpoint

The checkpoint that determines if the cell is ready to enter the S phase.

M checkpoint

The checkpoint that ensures all chromosomes are attached to the spindle before anaphase starts.

Cyclins

Proteins that regulate the cell cycle and activate cyclin-dependent kinases.

Growth Factors

External signals that stimulate cell division.

Density-Dependent Inhibition

A phenomenon where crowded cells stop dividing.

Anchorage Dependence

The requirement for cells to be attached to a substratum to divide.

Cancer Cells

Cells that divide uncontrollably due to loss of regulatory signals.

Tumor

A mass of abnormal cells that can be benign or malignant.

Benign Tumor

A tumor that remains at its original site and doesn't invade surrounding tissues.

Malignant Tumor

A tumor that invades surrounding tissues and can metastasize.

Metastasis

The spread of cancer cells to other parts of the body.

Cytoplasmic Signals

Molecules present in the cytoplasm that regulate the cell cycle.

Eukaryotic Cells

Cells with a true nucleus and organelles, including a structured cell cycle.

Prokaryotic Cells

Simple cells without a nucleus, typically reproduce by binary fission.

Microtubules

Cylindrical structures made of tubulin proteins that play a role in cell division.

Centrosome

A microtubule organizing center that helps form the mitotic spindle.

Kinetochores

Protein complexes that assemble on the centromere and attach to spindle microtubules.

Aster

A radial array of short microtubules that extends from the centrosome.

Experiment 1 (Cell Cycle Control)

A fusion experiment showing that cytoplasmic signals control cell cycle progression.

Experimental Results (G1 Checkpoint)

Cells need go-ahead signals to progress through the cell cycle.

Transformation

The process by which normal cells become cancerous.

Internal Signals

Regulatory signals from within the cell that affect the cell cycle.

External Signals

Regulatory signals from outside the cell that influence cell division.

Chromosome Duplication

The process of copying chromosomes in preparation for cell division.

Cell Growth

The increase in cell size that occurs during interphase.

Tissue Renewal

The process of replacing damaged or dead cells in multicellular organisms.

Cytoplasmic Regulation

The control of the cell cycle by signaling molecules in the cytoplasm.