The Cell Cycle

Flashcards about cell cycle phases and related terminology.

Cell Cycle

The life cycle of a cell, the period between successive divisions of a cell.

Binary Fission

The normal life cycle of a bacterial cell, involving replication, division, and interval phases.

Replication Phase (R-phase or C-period)

The phase in binary fission where the bacterial genome is replicated.

Division Phase (D-phase or D-period)

The phase in binary fission where daughter chromosomes and cellular components are segregated into daughter cells, initiated by FtsZ proteins forming the Z-ring.

Interval Phase (I-phase or B-period)

The phase in binary fission between division and the initiation of chromosome replication.

Highly Specialized Cells

Cells that lack the ability to divide (like RBCs and neurons).

Cells Inducible by Stimulus

Cells that can induce cell division by a specific stimulus (like liver cells and lymphocytes).

Cells with High Mitotic Activity

Cells with a relatively high level of mitotic activity (like hematopoietic stem cells and epithelial cells).

Interphase

G1, S, and G2 phases. In a typical human cell cycle of 24 hours, G1 lasts about 11 hours, S phase about 8 hours, G2 about 4 hours, and M about 1 hour.

G1 Phase

The gap phase after cell division, a growth and biosynthesis activity phase where the cell conducts checks before entering the S phase.

S Phase

The DNA synthesis phase, starting with DNA replication and finishing when the amount of DNA is doubled; duplication of centrioles takes place.

G2 Phase

The gap phase after DNA synthesis and before cell division, where the cell conducts checks before entering the M phase.

M Phase

The phase where the cell actually divides.

G0 Phase

The resting phase where most differentiated cells exit the cell cycle; cells may be quiescent or senescent.

Quiescent Cells

Dormant cells that may re-enter the cell cycle.

Senescent Cells

Aging or deteriorating cells that do not re-enter the cell cycle.