Cell Cycle and Mitosis – Key Vocabulary

Vocabulary flashcards covering the major terms related to the eukaryotic cell cycle, chromosome structure, and the stages of mitosis.

Cell Division

Process by which a cell reproduces itself, enabling growth, development, maintenance, and repair.

Binary Fission

Asexual reproduction in prokaryotes where the cell replicates its DNA and splits into two identical daughter cells.

Cell Cycle

Ordered series of events in eukaryotic cells composed of Interphase (G1, S, G2), Mitosis, and Cytokinesis.

Interphase

Longest part of the cell cycle during which the cell performs normal functions and prepares for division (includes G1, S, G2).

G1 Phase

First gap phase of Interphase; cell recovers from previous division, grows, and doubles organelles while gathering materials for DNA synthesis.

S Phase

Synthesis phase of Interphase in which DNA is replicated, producing two identical sister chromatids for each chromosome.

G2 Phase

Second gap phase of Interphase; cell synthesizes proteins necessary for mitosis and checks DNA for errors.

Chromatin

DNA-protein complex present during Interphase that is loosely packed and not visible under a light microscope.

Chromosome

Condensed, coiled structure of DNA and protein visible during mitosis; consists of two sister chromatids after DNA replication.

Sister Chromatids

Identical copies of a chromosome connected at the centromere following DNA replication.

Centromere

Region where sister chromatids are joined and where spindle fibers attach during mitosis.

Kinetochore

Protein complex at the centromere that serves as the attachment site for spindle microtubules.

Diploid (2n)

Condition of having two complete sets of chromosomes, one from each parent; typical of somatic cells.

Haploid (1n)

Condition of having one set of chromosomes; characteristic of gametes (egg and sperm).

Gametes

Haploid reproductive cells (oocyte and sperm) that unite during fertilization to form a diploid zygote.

Zygote

Diploid cell formed when two haploid gametes fuse during fertilization.

Homologous Chromosomes

Pair of chromosomes of the same type and length with genes for the same traits located at identical positions, one maternal and one paternal.

Autosomes

The 22 pairs of non-sex chromosomes in humans that carry genes unrelated to sex determination.

Sex Chromosomes

Chromosomes (X and Y in humans) that determine biological sex; XX is female, XY is male.

Mitosis

Nuclear division that produces two genetically identical diploid daughter cells; occurs in somatic cells.

Somatic Cell Division

Another term for mitosis; division of non-reproductive body cells.

Prophase

First stage of mitosis where chromatin condenses into chromosomes, nuclear membrane breaks down, and spindle apparatus begins to form.

Prometaphase

Late prophase stage characterized by complete nuclear envelope breakdown and attachment of spindle microtubules to kinetochores.

Asters

Star-shaped arrays of microtubules radiating from centrosomes during prophase to help orient the spindle.

Metaphase

Stage of mitosis where chromosomes align at the cell’s equatorial plane attached to spindle fibers.

Anaphase

Mitotic phase in which centromeres split and sister chromatids are pulled apart to opposite poles of the cell.

Telophase

Stage of mitosis where chromosomes reach poles, nuclear membranes reform, and chromosomes decondense back into chromatin.

Cytokinesis

Division of the cytoplasm resulting in two separate daughter cells; follows or overlaps telophase.

Cleavage Furrow

Indentation of the cell membrane in animal cells that deepens to separate daughter cells during cytokinesis.

Cell Plate

Structure that forms in plant cells during cytokinesis, eventually developing into a separating cell wall.

Spindle Fibers (Microtubules)

Protein filaments that emerge from centrosomes, attach to kinetochores, and segregate chromosomes during mitosis.