3.1 Cell division occurs in all organisms.

Vocabulary: DNA, chromosome

Review:

1. It leads to growth, development, and repair.

2. It condenses and forms chromosomes.

3. Cells divide to make more cells, which allow multicellular organisms to grow. As cells divide, they can specialize.

4. It wraps in coils around proteins, and then compacts further as it arranges into chromosomes.

5. Skin cells wear out quickly, so they duplicate frequently. Brain cells usually last a long time and do not replace themselves often. Skin heals faster because its cells are better equipped to replace themselves.