Mitosis and the cell cycle

• How many pairs of chromosomes do humans have?

  23 pairs
• What are chromosomes made of?

  DNA molecules
• What do DNA molecules code for?

  Genes
• What are the stages of the cell cycle?

  1. Stage 1: Longest stage, cell growth, increase in subcellular structures, DNA replication.
  2. Stage 2: Mitosis, chromosomes pulled to each cell, nucleus divides.
  3. Stage 3: Cytoplasm and cell membrane divide, resulting in 2 identical cells.
• What happens during Stage 1 of the cell cycle?

  Cells grow and DNA replicates, forming 2 copies of each chromosome
• What is the main event that occurs during mitosis?

  One set of chromosomes is pulled to each of the cells
• What happens to the nucleus during mitosis?

  The nucleus divides
• What occurs in Stage 3 of the cell cycle?

  The cytoplasm and cell membrane divide
• What is the result of the cell cycle?

  2 genetically identical cells
• Why is mitosis important for development?

  • Necessary for growth from an embryo to a baby
  • Provides more cells for development
• How does mitosis contribute to growth and repair?

  • Needed for cell growth during childhood and puberty
  • Provides new cells to repair damage