Stem cells

• What are stem cells?

  Undifferentiated cells that can specialize
• How can cells differentiate?

  Through changes in shape, contents, or organelle abundance
• Why do cells differentiate?

  Because certain genes are switched off or expressed
• Why do multicellular organisms need stem cells?

  They originate many specialized cell types for development
• How do specialized animal and plant cells differ in their ability to change?

  Animal cells remain in G0; plant cells can redifferentiate
• Where are stem cells found in humans?

  In early embryos and some adult tissues
• What are embryonic stem cells, and what is their potential?

  From embryos 3–5 days old; they are totipotent or pluripotent
• What are adult stem cells, and what is their potential?

  Found in tissues like bone marrow; they are multipotent
• What does totipotent mean?

  Can form any type of cell in the embryo and placenta
• What does pluripotent mean?

  Can form any type of cell in the embryo, not placenta
• What does multipotent mean?

  Can form a limited number of specialized cell types
• What is the origin of totipotent and pluripotent stem cells compared to multipotent stem cells?

  Totipotent and pluripotent are embryonic; multipotent are adult
• What are the medical uses of stem cells?

  Bone marrow transplants, drug research, tissue growth
• How are stem cells used in bone marrow transplants?

  To treat leukemia and return after chemotherapy
• Why are stem cells used for drug testing?

  They provide more valid results than animal tissues
• How do stem cells help in studying developmental biology?

  They help understand growth, development, and differentiation
• How could stem cells help replace tissues or organs?

  By growing specific cells for various diseases
• How could stem cells treat type-1 diabetes?

  By growing replacement pancreatic cells
• How could stem cells treat neurodegenerative diseases?

  By growing nerve tissue for Alzheimer’s and Parkinson’s
• How could stem cells help heart disease patients?

  By growing replacement heart cells for repair
• What ethical issues are associated with embryonic stem cells?

  Concerns about destroying embryos for research
• Why are adult stem cells less controversial?

  They are donated with consent, causing no harm
• What practical challenges exist in stem cell research?

  Expensive, slow, hard to control differentiation
• What are the risks of stem cell therapies?

  Tumors may form if differentiation is uncontrolled
• What are the main types of stem cells used in medicine?

  Embryonic (totipotent or pluripotent) and adult (multipotent)
• What makes embryonic stem cells unique?

  They can form almost any cell type in the body
• What makes adult stem cells different from embryonic stem cells?

  They can form a limited range of cell types
• What is the role of stem cells in cancer treatment?

  To restore healthy blood cells after chemotherapy
• How could stem cells be used to repair spinal cord injuries?

  By growing new nerve tissue to replace damaged cells
• Why is testing drugs on human stem cells advantageous?

  It offers more accurate predictions of human responses
• What is the significance of stem cells in understanding differentiation?

  They allow study of gene activation during development
• How do stem cells contribute to regenerative medicine?

  By potentially growing tissues or organs for treatment
• What challenges do scientists face with differentiation of stem cells?

  Identifying signaling molecules and controlling differentiation
• Why might tumors form during stem cell therapy?

  Uncontrolled differentiation can lead to cell growth
• What are the steps to using bone marrow stem cells for transplantation?

  Harvest, process, and transplant into the recipient
• How do ethical concerns differ between embryonic and adult stem cells?

  Embryonic raise concerns about destroying embryos
• How could stem cells help in Alzheimer’s treatment?

  By growing replacement nerve cells for memory loss
• How could stem cells help in Parkinson’s treatment?

  By replacing specific brain cells to reduce tremors
• What are the two main types of blood cells formed from bone marrow stem cells?

  Neutrophils and erythrocytes
• What is the function of neutrophils?

  They are white blood cells that fight infection