Mitosis

• Why do multicellular eukaryotic organisms need new cells?

  For growth, development, and repair
• What is the process called through which cells are generated?

  The cell cycle
• What are the three main stages of the cell cycle?

  Growth, DNA replication, and mitosis
• What happens during the first step of the cell cycle?

  The cell grows and increases subcellular structures
• What occurs during DNA replication?

  The DNA is duplicated for new cells
• How is DNA structured when a cell is not dividing?

  It is spread out in long strings
• What happens to DNA when a cell prepares for division?

  It condenses into chromosomes
• What do chromosomes contain?

  A large number of genes
• How many copies of each chromosome do eukaryotic cells have?

  Two copies, one from each parent
• How many pairs of chromosomes do humans have?

  23 pairs
• Why can't animals of different species reproduce fertile offspring?

  They have different numbers of chromosomes
• What shape do duplicated chromosomes take?

  An X shape
• What is the significance of the right arm of each chromosome?

  It is a duplicate of the left arm
• What do we call the process of the cell membrane and cytoplasm pulling apart?

  Cytokinesis
• What happens to the chromosomes during cytokinesis?

  They are divided between two daughter cells
• What do the resulting daughter cells contribute to?

  Growth, development, or repair
• What are the stages of the cell cycle?

  1. Growth
  2. DNA replication
  3. Mitosis and cytokinesis
• How does the structure of chromosomes change during the cell cycle?

  • DNA is long and spread out when not dividing
  • DNA condenses into X-shaped chromosomes when preparing for division
  • Each chromosome duplicates and forms two identical arms
• What is the role of chromosomes in cell division?

  • Carry genetic information
  • Ensure each daughter cell receives identical DNA
  • Facilitate the process of cell division