| A | B |
|---|
| chromosome | long, continuous thread of DNA that consists of numerous genes and regulatory information |
| histone | protein that organizes chromosomes and around which DNA wraps |
| chromatin | loose combination of DNA and proteins that is present during interphase |
| chromatid | one half of a duplicated chromosome |
| centromere | region of condensed chromosome that looks pinched; where spindle fibers attach during meiosis and mitosis |
| telomere | repeating nucleotides at the ends of DNA molecules that do not form genes and help prevent loss of genes |
| prophase | first phase of mitosis when chromatin condenses, the nuclear envelope breaks down, the nucleolus disappears, and the centrosomes and centrioles migrate to opposite sides of the cell |
| metaphase | second phase of mitosis when spindle fibers align the chromosomes along the cell equator |
| anaphase | third phase of mitosis during which chromatids separate and are pulled to opposite sides of the cell |
| telophase | last phase of mitosis when a complete set of identical chromosomes is positioned at each pole of the cell, the nuclear membranes start to form, the chromosomes begin to uncoil, and the spindle fibers disassemble |
