Unit 2 – The Cell Cycle Flashcards

A set of vocabulary flashcards defining essential terms, phases, and concepts related to the cell cycle, mitosis, meiosis, and prokaryotic binary fission.

Cell Cycle

The series of events that a cell goes through as it grows, prepares for division, and produces new cells.

Interphase

The longest stage of the cell cycle where the cell grows, copies its DNA, and serves as preparation for cell division.

Cell Division

A vital biological process in which a single cell splits into two or more daughter cells, enabling growth, repair, and reproduction in organisms.

Mitosis

A type of cell division that produces identical body cells used for growth, repair, and replacement.

Meiosis

A type of cell division in sexually reproducing organisms that produces reproductive cells (gametes) and reduces the chromosome number to haploid ($n$), generating genetic variation.

Apoptosis

Programmed cell death used by the body to remove damaged or unnecessary cells.

Necrosis

An uncontrolled form of cell death caused by injury, infection, or lack of blood supply that often results in inflammation and damage to nearby tissues.

Tumor

A mass of abnormal cells caused by uncontrolled cell division, which may be benign (non-cancerous) or malignant (cancerous).

Cancer

A condition where abnormal cells divide uncontrollably and may spread to other parts of the body.

G1 Phase

The first stage of interphase (preparation stage) where the cell grows larger, organelles such as mitochondria and ribosomes increase in number, and proteins and enzymes for DNA replication are produced.

G0 Phase

A nondividing state into which a cell switches if it does not receive the go-ahead signal at a checkpoint.

S Phase

The synthesis stage of interphase where DNA replicates inside the nucleus, producing two identical sister chromatids joined at the centromere for each chromosome.

G2 Phase

The stage of interphase where the cell continues to grow, synthesizes more proteins and microtubules, checks and repairs DNA, and prepares for mitosis.

M-Phase

The stage of the cell cycle where the cell divides its nucleus through mitosis, consisting of Prophase, Metaphase, Anaphase, and Telophase.

Prophase (Mitosis)

The first stage of mitosis where chromatin condenses into visible chromosomes, the nucleolus disappears, the nuclear envelope breaks down, centrosomes move to opposite poles, and spindle fibers form.

Metaphase (Mitosis)

The stage of mitosis where chromosomes line up in the center of the cell along the metaphase plate to prepare for separation.

Anaphase (Mitosis)

The stage of mitosis where centromeres split, sister chromatids separate, and spindle fibers pull each chromatid toward opposite poles.

Telophase (Mitosis)

The final stage of mitosis where new nuclear membranes form around the separated chromosomes at opposite poles.

Cytokinesis

The division of the cytoplasm following nuclear division, resulting in two distinct daughter cells.

Cleavage Furrow

A structure formed during cytokinesis in animal cells when the cell membrane pinches inward.

Cell Plate

A structure formed between two new cells during cytokinesis in plant cells to give rise to a new cell wall.

Binary Fission

A simple, rapid, and efficient cell division process in prokaryotes where single circular DNA replicates, moves to opposite ends, and splits the cell into two genetically identical daughter cells via a septum.

Chromosomes

Compact structures inside the cell nucleus composed of long strands of DNA wrapped around proteins called histones.

Chromatin

The loose, thread-like complex of DNA and proteins (primarily histones) found in the nucleus of eukaryotic cells during interphase.

Chromatid

A highly condensed, rod-like structure that represents one-half of a duplicated chromosome.

Crossing Over

The physical exchange of DNA between non-sister chromatids of paired homologous chromosomes during Prophase I of meiosis, creating new allele combinations.

Synapsis

The physical aligning and pairing up of homologous chromosomes along their entire length during Prophase I of meiosis.

Tetrad

A structure formed during Prophase I of meiosis consisting of a pair of homologous chromosomes with four total chromatids; also known as a bivalent.

Independent Assortment

The phenomenon in Metaphase I of meiosis where the orientation of each paired homologous chromosome (tetrad) at the cell equator is random.

Interkinesis

A short time frame between Meiosis I and Meiosis II that enables cellular machinery to rearrange without DNA replication.