CB2 cells and control

• What are the two types of cell division?

  Mitosis and Meiosis
• What is the purpose of mitosis?

  For growth and repair
• What type of cells does mitosis produce?

  Diploid cells identical to each other
• What is the purpose of meiosis?

  For sexual reproduction
• What type of cells does meiosis produce?

  Haploid cells different from each other
• How many cells do humans consist of?

  Trillions of cells
• What are the benefits of having trillions of cells in humans?

  • Specialization of cells for tasks
  • Formation of organs for efficiency
  • Ability to grow very large
• Why are new cells needed throughout life?

  For growth, repair, and replacing damaged cells
• What type of chromosomes do normal human body cells have?

  Diploid chromosomes
• How many chromosomes do human body cells have?

  46 chromosomes
• What is the process called when chromosomes are copied in mitosis?

  Mitosis
• What happens to chromosomes during mitosis?

  They are copied exactly and linked
• What is the role of centromeres in mitosis?

  They link new chromosomes together
• What happens to chromosomes before the cell divides in mitosis?

  They are moved to opposite sides of the cell
• What is the result of mitosis?

  Two identical diploid cells
• Why is constant cell division important?

  To prevent cells from becoming too large
• What happens to the surface-area-to-volume ratio as a cell grows larger?

  It becomes smaller
• Why is it more efficient for large organisms to be multicellular?

  To maintain material exchange with the environment
• What type of cells does meiosis produce?

  Male and female gametes
• How many chromosomes do gametes contain?

  23 chromosomes
• What is formed at fertilization?

  The zygote
• How many pairs of chromosomes does a zygote contain?

  23 pairs of chromosomes
• What does the zygote contain from each parent?

  A complete set of chromosomes
• Where are gametes formed?

  In the reproductive organs
• What is the process called that forms gametes?

  Meiosis
• What are the key differences between mitosis and meiosis?

  Mitosis:

  • Produces diploid cells
  • Used for growth and repair
  • Cells are identical

  
  

  Meiosis:

  • Produces haploid cells
  • Used for sexual reproduction
  • Cells are different
• What is faster, asexual or sexual reproduction?

  Asexual reproduction
• Why does asexual reproduction not produce variation?

  It relies on a single parent organism
• What can uncontrolled cell division lead to?

  Formation of tumours
• How can cancer cells damage the body?

  By forming tumours that disrupt normal function
• What type of reproduction involves just one parent?

  Asexual reproduction
• What are the offspring produced by asexual reproduction like?

  They are clones, genetically identical
• What process does asexual reproduction rely on?

  Mitosis
• Compare asexual reproduction and sexual reproduction.

  • Asexual reproduction:
  • Faster process
  • No variation in offspring
  • Involves one parent
  • Offspring are clones
  • Sexual reproduction:
  • Slower process
  • Produces variation in offspring
  • Involves two parents
• What are the consequences of uncontrolled cell division?

  • Formation of cancer cells
  • Development of tumours
  • Potential damage to body functions
  • Risk of death
• Mitosis

   

  Mitosis consists of the following stages:

   

  1.     Prophase

  Chromosomes condense and become more visible. The nuclear membrane starts to break down and spindle fibres appear.

   

  2.     Metaphase

  The chromosomes line up on the spindle fibres across the middle of the cell.

   

  3.     Anaphase

  The chromosome copies are separated and pulled to opposite sides of the cell.

   

  4.     Telophase

  The nuclear membrane forms around each set of chromosomes to form nuclei.

   

   

   
• What is the process called that produces new cells?

  The cell cycle
• Why do living things need the cell cycle?

  To grow and repair themselves
• What are the two phases of the cell cycle?

  1. Interphase
  2. Mitosis
• What happens during interphase of the cell cycle?

  Cell makes organelles and replicates DNA