cell division

• What does the nucleus of a cell contain?

  Chromosomes
• What do chromosomes carry?

  A large number of genes
• How are chromosomes found in normal body cells?

  In pairs
• What are chromosomes made of?

  DNA molecules
• What is the cell cycle?

  A series of stages for cell division
• Why is cell division by mitosis important?

  For growth and repair of cells
• What is produced by cell division through mitosis?

  Two identical daughter cells
• What are the stages of the cell cycle?

  1. Cell grows bigger
  2. DNA replicates (chromosomes are doubled)
  3. Increase in number of sub-cellular structures (ribosomes, mitochondria)
  4. Mitosis: chromosomes pulled to each end, nucleus divides
  5. Cytoplasm and cell membrane divide to form two identical daughter cells
• What is a stem cell?

  An undifferentiated cell
• What can stem cells develop into?

  One or more types of specialised cells
• What are the two types of stem cells in mammals?

  Adult and embryonic
• What can stem cells be cloned to produce?

  Large numbers of identical cells
• What are the characteristics of adult stem cells?

  • Found in specific parts of the body (bone marrow)
  • Can only differentiate into certain types of specialised cells
  • Fewer ethical issues
  • Established techniques for treating diseases
  • Relatively safe and quick recovery for donors
• Where are adult stem cells found?

  Bone marrow
• What can adult stem cells differentiate into?

  Certain types of specialised cells
• What are the advantages and disadvantages of adult stem cells?

  Advantages:

  • Fewer ethical issues
  • Established treatment techniques
  • Safe and quick recovery for donors

  
  

  Disadvantages:

  • Requires a donor, leading to wait times
  • Limited differentiation potential
• What are the characteristics of embryonic stem cells?

  • Found in early human embryos
  • Can differentiate into any type of specialised cells
  • Can treat a wide range of diseases
  • May grow whole replacement organs
• What can embryonic stem cells differentiate into?

  Any type of specialised cells
• What are the advantages and disadvantages of embryonic stem cells?

  Advantages:

  • Can treat a wide range of diseases
  • Possible to grow whole replacement organs
  • Usually no donor needed

  
  

  Disadvantages:

  • Ethical issues regarding potential life
  • Risk of viral infections
  • Relatively under-researched
• What are the characteristics of plant meristem cells?

  • Found in roots and shoots of plants
  • Can differentiate into all cell types
  • Used to create clones of whole plants
• What can plant meristem cells differentiate into?

  All cell types
• What are the advantages and disadvantages of using plant meristem cells?

  Advantages:

  • Cloning rare species to prevent extinction
  • Cloning plants with desirable traits
  • Fast and low-cost production of plants

  
  

  Disadvantages:

  • Genetic uniformity risks entire crop
• What is therapeutic cloning?

  Creating a cloned early embryo from patient cells
• Why are stem cells from a cloned embryo used for medical treatments?

  They can grow new organs and treat diseases
• What is the genetic advantage of using stem cells from a patient's cloned embryo?

  They have the same genes as the patient
• How does the genetic similarity of stem cells affect transplant success?

  It reduces the likelihood of rejection
• What are the key steps and benefits of therapeutic cloning?

  • Cells from the patient's body are collected
  • A cloned early embryo is created
  • Stem cells are harvested from the embryo
  • Benefits:
  • Stem cells can be used for medical treatments
  • Potential to grow new organs
  • Reduced rejection risk due to genetic similarity