mitosis

• Why do multicellular eukaryotic organisms need new cells?

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

  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 in the cell cycle?

  The DNA is duplicated for new cells
• How does DNA appear 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 chromosomes take when duplicated?

  An X shape
• What are the two sides of the cell called during division?

  Poles
• What happens to the chromosomes during cell division?

  They are pulled to opposite sides of the cell
• What is cytokinesis?

  The division of the cell membrane and cytoplasm
• 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 facilitate cell division?

  • Chromosomes condense for easy separation
  • Each chromosome has identical copies for distribution
  • X shape allows for organized pulling to poles
• What is the significance of genes in chromosomes?

  • Control development of characteristics
  • Determine traits like eye color
  • Essential for organism's biological functions