Understanding the Cell Cycle and Mitosis

Cell Cycle

Life of a cell from formation to division.

Interphase

Longest phase of the cell cycle (90%).

Mitosis

Division of the nucleus into two identical nuclei.

Cytokinesis

Division of the cytoplasm after mitosis.

Chromatin

Non-condensed form of DNA in interphase.

Chromosome

Condensed DNA structure during cell division.

Sister Chromatids

Identical copies of a chromosome joined together.

Centromere

Region where sister chromatids are attached.

Kinetochore

Protein structure linking chromatids to spindle.

Genome

Total genetic information of a cell.

Prokaryotes

Organisms with singular, circular DNA.

Eukaryotes

Organisms with linear chromosomes.

Homologous Chromosomes

Chromosomes from each parent with same genes.

Somatic Cells

Body cells that are diploid (2n).

Gametes

Reproductive cells that are haploid (n).

Diploid

Cells with two sets of chromosomes (2n).

Haploid

Cells with one set of chromosomes (n).

G1 Phase

First gap phase; cell growth occurs.

S Phase

Synthesis phase; DNA replication occurs.

G2 Phase

Second gap phase; preparation for mitosis.

Prophase

Chromatin condenses; spindle begins to form.

Prometaphase

Nuclear envelope fragments; microtubules attach to kinetochores.

Metaphase

Chromosomes align at the metaphase plate.

Anaphase

Sister chromatids separate to opposite cell ends.

Telophase

Nuclear membranes reform; chromosomes de-condense.

G1 Checkpoint

Checks cell size, growth factors, and DNA damage.

G0 Phase

Non-dividing state some cells enter.

G2 Checkpoint

Checks DNA replication completion and damage.

M Checkpoint

Checks microtubule attachment to chromosomes.

Cyclins

Proteins regulating the cell cycle phases.

CDKs

Enzymes active with specific cyclins present.

Growth Factors

Hormones stimulating cell growth and division.

Contact Inhibition

Cells stop dividing upon contact with others.

Anchorage Dependence

Cells require attachment to divide.

Cancer Cells

Cells that divide uncontrollably due to mutations.

Benign Tumor

Non-cancerous mass of abnormal cells.

Malignant Tumor

Cancerous mass capable of spreading.

Metastasis

Spread of cancer cells to other body parts.

Apoptosis

Programmed cell death in response to damage.

Tumor

Mass of tissue formed by abnormal cell growth.

Cancer Prevention

Strategies to minimize cancer risk.

DNA Mutations

Changes in DNA leading to cancer.

Cell Cycle Regulation

Control points ensuring proper cell cycle progression.

Chromosome Number

Humans have 46 chromosomes (2n=46).

Chromatid Count

After S phase, 4 chromatids present.