Mitosis

• Why do multicellular eukaryotic organisms require a continuous supply of new cells?


  They require new cells for growth, development, and repair.
• What is the process through which new cells are generated called?


  The process is known as the cell cycle.
• What are the three main stages of the cell cycle?


  The three main stages are growth, DNA replication, and mitosis (division or cytokinesis).
• What happens during the first step of the cell cycle?

  The cell grows in size and increases the number of subcellular structures it contains.
• What occurs during DNA replication in the cell cycle?

  The DNA is duplicated so that the two new cells will each have a full set of DNA.
• How does DNA appear when a cell is not dividing?


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


  The DNA condenses into chromosomes.
• What do chromosomes contain?


  Chromosomes contain a large number of genes.
• How many copies of each chromosome do eukaryotic cells have?


  Eukaryotic cells have two copies of each chromosome, known as a pair.
• How many pairs of chromosomes do humans have?

  Humans have 23 pairs of chromosomes.
• Why can't animals of different species reproduce to have fertile offspring?


  Different species have different numbers of chromosomes.
• What happens to each of the 46 chromosomes during cell division?


  Each chromosome duplicates and stays attached to the original chromosome, forming an X shape.
• What is the significance of the right and left arms of the X-shaped chromosome?

  The right arm is a duplicate of the left arm, containing the same DNA.
• What occurs when the cell is ready to divide?

  All 46 chromosomes line up along the center of the cell.
• What attaches to the chromosomes during cell division?

  Fibers from either side of the cell attach to their respective half of each chromosome.
• What happens to the chromosomes during the pulling process in cell division?

  The pulling process breaks the chromosomes in half into two separate arms.
• What is the final stage of the cell cycle called?

  The final stage is called cytokinesis.
• What occurs during cytokinesis?

  The cell membrane and cytoplasm pull apart, forming two daughter cells.
• What is the result of cell division in terms of genetic material?

  Each daughter cell has the same DNA and is identical to each other and to the parent cell.
• What can the resulting daughter cells contribute to after division?

  The resulting daughter cells can contribute to growth, development, or repair.
• What happens to the daughter cells after they are formed?

  The daughter cells undergo the cell cycle all over again.
• What are the stages of the cell cycle and their functions?

  1. Growth: Cell increases in size and number of organelles.
  2. DNA Replication: DNA is duplicated for two new cells.
  3. Mitosis (Cytokinesis): Division of the cell into two identical daughter cells.
• What is the significance of chromosomes in cell division?


  • Chromosomes condense to ensure accurate DNA distribution.
  • Each chromosome duplicates and forms an X shape.
  • Chromosomes ensure genetic consistency in daughter cells.