The Cell Cycle

Cell cycle

Interphase, mitosis, cytokinesis

Restriction checkpoint

determines fate of cell: to continue cell cycle and divide, to enter a non-dividing stage as a specialized cell, or to die

Interphase

Before cell division begins, where the cell grows and synthesizes new molecules, membranes, DNA, and organelles (longest phase) (G1, S, G2)

G1 & G2

Phases where the cell grows, and structures other than DNA are duplicated

Synthesis

Phase where DNA of the cell is replicated in preparation for cell division

Meiosis

Only used for sperm & egg cell production (half the normal number of chromosomes)

Mitosis

Process of a single cell divides its replicated DNA into two identical nuclei, creating two genetically identical daughter cells (creates somatic cells)

Prophase

Chromosomes condense into visible structures, the nuclear membrane breaks down, and spindle fibers start to form

Prometaphase

The nuclear envelope completely breaks down, and spindle fibers attach to the kinetochores (centromeres) on the chromosomes

Metaphase

Chromosomes line up single-file along the equator (metaphase plate) of the cell

Anaphase

Sister chromatids are pulled apart by spindle fibers toward opposite poles (centrosomes) of the cell

Telophase

New nuclear membranes form around the two sets of chromosomes, which begin to decondense back into chromatin

Cytokinesis

The cytoplasm divides, splitting the original cell into two identical daughter cells

Apoptosis

Programmed cell death