The Cell Cycle

The cell cycle G1: Growth and cell “work” S: Synthesis of DNA/a copy of the blueprints of life is made G2: prepare for division G1, S, G2 together are called “INTERPHASE” M: Mitosis when the cell divides into two cells

Why do cells divide? Adds new cells for growth. Replaces worn out cells. Cells cannot grow too large because of surface area to volume ratio issues. Cells need lots of surface area to exchange resources with the environment surrounding the cell.

Why “S” Phase happens…DNA replication Prior to mitosis, the DNA must replicate itself so each new cell has the same amount of DNA as the parent cell

Parent Cell Daughter Cells

Steps of Mitosis Prophase- nuclear membrane dissolves, chromosomes become visible Metaphase- Chromosomes line up in the middle of the cell Anaphase- individual chromatids are pulled apart to opposite ends of the cell Telophase- new nuclear membranes form to create two nuclei Cytokinesis- the cell divides to form two

Diagram of a Chromosome

Mitosis

Animation explaining cell cycle https://www.youtube.com/watch?v=JcZQkmooyPk Time lapse of a lily cell splitting https://www.youtube.com/watch?v=aDAw2Zg4IgE Baylor University students doing “Mitosis Dance” https://www.youtube.com/watch?v=ZEwddr9ho-4