Cell Cycle – Interphase and Related Concepts

Vocabulary flashcards summarizing key terms and definitions related to Interphase, mitosis, and overall cell cycle events.

Cell Cycle

The ordered series of events that leads to cell growth and division; includes Interphase and M phase.

Interphase

The most active, metabolically busy part of the cell cycle (>95% of its duration) in which the cell grows and prepares for division.

Resting Phase (historical term for Interphase)

A misnomer describing Interphase when no visible chromosomal changes occur, although intense metabolic activity proceeds.

M Phase (Mitotic Phase)

Portion of the cell cycle encompassing mitosis and cytokinesis, during which the nucleus and cytoplasm divide.

G₁ Phase (1st Gap / Pre-DNA-synthesis Phase)

Interphase sub-stage between mitosis and DNA replication; characterized by rapid cell growth and synthesis of RNA, proteins, and most organelles.

S Phase (DNA Synthesis Phase)

Interphase sub-stage where nuclear DNA and histone proteins are replicated, doubling DNA content from 2C to 4C without changing chromosome number (remains 2n).

G₂ Phase (2nd Gap / Post-DNA-synthesis Phase)

Interphase sub-stage involving final preparation for mitosis, continued growth, and synthesis of mitotic proteins such as tubulin.

Cytokinesis

Division of the cytoplasm following nuclear division, completing cell division.

Prophase

First stage of mitosis involving chromatin condensation and spindle apparatus formation.

Metaphase

Mitotic stage in which chromosomes align at the cell’s equatorial plate.

Anaphase

Mitotic stage where sister chromatids separate and move toward opposite poles.

Telophase

Final mitotic stage marked by chromosome de-condensation and nuclear envelope re-formation.

DNA Replication

The process of copying the cell’s DNA during S phase, doubling genetic material.

Histone Proteins

Proteins synthesized during S phase that package and organize DNA into nucleosomes.

Centriole Duplication

Event during S phase in animal cells where centrioles replicate in preparation for spindle formation.

Tubulin

Protein produced in G₂ that polymerizes to form microtubules of the mitotic spindle.

Spindle Fibres

Microtubule structures that attach to chromosomes and help segregate them during mitosis.

Diploid (2n)

Condition of having two complete sets of chromosomes; chromosome number remains 2n throughout S phase even though DNA content doubles.

2C → 4C DNA Content

Notation indicating DNA quantity doubles during S phase (from two to four copies) while chromosome count stays constant.