The Cell Cycle and Mitosis

Vocabulary flashcards covering the cell cycle, stages of mitosis, cell cycle regulation, apoptosis, and the genetic basis of cancer.

Cell Cycle

A cell process composed of Interphase, where chromosomes are replicated during $\text{G}_1$, $\text{S}$, and $\text{G}_2$ phases, and M phase (Mitosis), which involves the division of the nucleus and cytoplasm.

Mitosis

Cell division used for growth and repair (cloning division) that produces daughter cells genetically identical to the parent cell, consisting of four phases: Prophase, Metaphase, Anaphase, and Telophase.

Prophase

The phase of mitosis in a diploid cell ($2n$) where the nuclear envelope degrades and replicated chromosomes from interphase become condensed.

Metaphase

The phase of mitosis acting as a checkpoint in cell division during which chromosomes line up individually at the metaphase plate.

Anaphase

The phase of mitosis in which centromeres dissolve and sister chromatids separate, moving towards opposite poles of the cell.

Telophase

The phase of mitosis where chromosomes condense again, the nuclear envelope reforms, and two new identical daughter cells are created.

Telomeres

Structures located at the tips of chromosomes that are degraded with each mitosis.

Apoptosis

Programmed cell death triggered when a death receptor receives a signal for the cell to die, causing intracellular enzymes to begin degrading cellular components.

Benign Tumor

A tumor that stays in one place and does not grow into surrounding tissue.

Malignant Tumor

An invasive tumor that moves to other parts of the body.

Metastasis

The movement of cancer cells around the body.

Proto-oncogenes

Genes that normally trigger cell division and have the potential to become cancerous; estimated to comprise $1\%$ of the $\sim 30,000$ genes in the human genome.

Oncogenes

Genes that convert cells into cancer cells when mutated or expressed at abnormally high levels.

Inherited Cancers

Cancers caused by damage to both germline and somatic cells, resulting in inherited cancer susceptibility; rare and typically occurring earlier in life than somatic cancers.

Sporadic Cancers

Cancers caused by spontaneous damage to somatic (non-sex) cells resulting from a single dominant mutation or two recessive mutations in the same gene, with susceptibility not passed to offspring.

Telomerase Activation

The process in cancer cells where telomerase is turned on, extending telomere length and contributing to uncontrollable cell division.