The Cell Cycle: An Overview

Vocabulary flashcards covering the key phases, stages, structures, and checkpoints of the cell cycle and mitosis.

Cell Cycle

An ordered set of events that culminates in cell division, crucial for growth, repair, and reproduction in organisms.

Interphase

The longest part of the cell cycle, during which the cell grows, duplicates its DNA, and prepares for division. It consists of G1, S, and G2 sub-phases.

M Phase

The phase of the cell cycle involving two major processes: mitosis (nuclear division) and cytokinesis (cytoplasmic division).

G1 Phase (First Gap)

A sub-phase of Interphase where the cell grows, synthesizes proteins, carries out normal metabolic functions, and decides whether to divide or enter a resting state (G0).

S Phase (Synthesis)

A sub-phase of Interphase where DNA replication occurs, resulting in each chromosome being duplicated into two identical sister chromatids joined at the centromere.

G2 Phase (Second Gap)

A sub-phase of Interphase where the cell continues to grow, synthesizes proteins and organelles in preparation for mitosis, and checks duplicated chromosomes for errors.

Mitosis

The process of nuclear division where replicated chromosomes are separated into two new, genetically identical nuclei, essential for asexual reproduction, growth, and repair.

Cytokinesis

The division of the cytoplasm, usually overlapping with the late stages of mitosis, resulting in two distinct daughter cells.

Prophase

The first stage of Mitosis where chromosomes condense and become visible, the nuclear envelope begins to break down, and the mitotic spindle starts to form.

Sister Chromatids

Two identical copies of a chromosome that are joined together at the centromere after DNA replication.

Centromere

The constricted region of a chromosome where two sister chromatids are joined.

Mitotic Spindle

A structure made of microtubules that forms from centrosomes and is responsible for separating chromosomes during mitosis.

Metaphase

The second stage of Mitosis where the chromosomes align along the metaphase plate, and spindle fibers attach to the kinetochores.

Metaphase Plate

An imaginary equator in the middle of the cell where chromosomes align during metaphase.

Kinetochores

Protein structures on the centromeres of sister chromatids where spindle fibers attach.

Anaphase

The third stage of Mitosis where sister chromatids separate and are pulled apart towards opposite poles of the cell by the shortening of spindle microtubules.

Telophase

The fourth stage of Mitosis where chromosomes arrive at opposite poles, begin to decondense, new nuclear envelopes form, and the mitotic spindle disassembles.

Cleavage Furrow

In animal cells, an indentation that forms during cytokinesis, pinching the cell into two distinct daughter cells.

Cell Plate

In plant cells, a structure that forms in the middle of the cell during cytokinesis, eventually developing into a new cell wall separating the daughter cells.

Cell Cycle Checkpoints

Control mechanisms that ensure the proper progression of the cell cycle, preventing errors and allowing for repair.

G1 Checkpoint

A cell cycle checkpoint that checks for cell size, nutrients, growth factors, and DNA damage; if conditions are not favorable, the cell may enter the G0 phase.

G2 Checkpoint

A cell cycle checkpoint that checks for cell size, completion of DNA replication, and DNA damage.

M Checkpoint (Spindle Checkpoint)

A cell cycle checkpoint that occurs during metaphase, ensuring that all sister chromatids are properly attached to the spindle microtubules before anaphase begins.