Chapter 2 - Cell division

• What are chromosomes made of?

  The molecule DNA
• How many pairs of chromosomes do human body cells contain?

  23 pairs of chromosomes
• What type of cells have unpaired chromosomes?

  Gametes
• What is the process called when cells divide?

  The cell cycle
• How many identical cells are formed at the end of mitosis?

  Two identical cells
• What is the significance of mitosis for multicellular organisms?

  It is essential for growth and development
• When does mitosis occur in an organism?

  When an organism repairs itself
• What are the stages of the cell cycle involving mitosis?

  1. DNA replication: forms two copies of each chromosome
  2. Mitosis: one set of chromosomes pulled to each end
  3. Cytoplasm and cell membrane divide: forms two identical cells
• What are the functions of mitosis?

  • Essential for growth and development of multicellular organisms
  • Repairs damaged tissues (e.g., healing a broken bone)
  • Occurs during asexual reproduction
• What is a stem cell?

  An undifferentiated cell that can differentiate
• Where are stem cells found in animals?

  In embryos and adult organisms
• Where are stem cells found in plants?

  In meristem tissue at root tips and buds
• What happens during fertilization in humans?

  A sperm cell joins with an ovum
• What is the process called when cells become specialized?

  Differentiation
• What are embryonic stem cells capable of?

  They can differentiate into any body cell
• How do adult stem cells differ from embryonic stem cells?

  Adult stem cells cannot differentiate into all cell types
• What is a common use of stem cells in medicine?

  Bone marrow transplants for leukemia treatment
• What is the first step in a bone marrow transplant for leukemia?

  Destroying the patient's existing bone marrow
• What is a risk associated with bone marrow transplants?

  Donor compatibility issues
• What is therapeutic cloning?

  Producing an embryo with the patient's genes
• Why are stem cells from therapeutic cloning less likely to be rejected?

  They have the same genes as the patient
• What medical conditions could therapeutic cloning potentially help?

  Diabetes and paralysis
• What ethical concerns are associated with therapeutic cloning?

  Objections based on ethics or religion
• What is meristem tissue in plants?

  Stem cells that can differentiate into any plant tissue
• How can meristem tissue be used in agriculture?

  To produce clones of plants quickly
• Why might farmers want to clone plants?

  To produce disease-resistant crop plants
• What are the main uses of stem cells in medicine and agriculture?

  • Medical treatments (e.g., bone marrow transplants)
  • Therapeutic cloning for various conditions
  • Cloning plants for agriculture
• What are the differences between embryonic and adult stem cells?

  • Embryonic stem cells:
  • Undifferentiated
  • Can become any cell type
  • Adult stem cells:
  • Limited differentiation
  • Found in specific tissues (e.g., bone marrow)
• What are the advantages and disadvantages of using stem cells in medicine?

  Advantages:

  • Potential to treat various diseases
  • Can regenerate damaged tissues

  
  

  Disadvantages:

  • Ethical concerns
  • Risk of rejection(may only occur in adult stem cells) transfer of viral infection