| A | B |
|---|
| Gap1 (G1) | 1st stage of cell cycle: Cells grow, carry out normal functions, and replicate their organelles |
| Synthesis (S) | 2nd stage: DNA replication duplicates chromosomes, resulting in two identical copies (sister chromatids) |
| Gap 2 (G2) | 3rd stage: additional growth, duplication of centrioles (centrosomes) |
| Mitosis (M) | 4th stage of cell cycle: division of nucleus and contents (mitosis) and division of cytoplasm (cytokinesis) |
| mitosis | division of the nucleus and its contents (divided into 4 phases) |
| cytokinesis | division of the cytoplasm, producing 2 daughter cells |
| chromosome | one long continues thread of DNA that consists of numerous genes along with regulatory information |
| histones | positively charged proteins that DNA wraps around, forming chromatin |
| chromatin | the loose combination of DNA and proteins in interphase, when the cell is not actively dividing |
| chromatid | one half of a duplicated chromosome (sister chromatids) |
| prophase | chromatin condenses to form chromosomes, the nuclear envelope breaks down, centrioles begin to move to opposite poles, spindle fibers form |
| metaphase | spindle fibers attach to each chromosome and chromosomes are aligned along the equator |
| anaphase | chromatids separate and move to opposite sides of the cell |
| telophase | chromosomes begin to decondense, nuclear membranes start to reform, spindle fibers disappear |
| interphase | the cell copies its DNA and grows in preparation for division |
 | 1st stage of mitosis, prophase |
 | 2nd stage of mitosis, metaphase |
 | 3rd stage of mitosis, anaphase |
 | final stage of mitosis, telophase |
| Gap 0 (G0) | cells have left the cell cycle, are not dividing but are metabolically active |
