Stem cells

• What is a stem cell


  An undifferentiated cell of an organism which is capable of dividing into many more cells of the same type
• Name 3 types of stem cells

  -embryonic stem cells

  -adult stem cells

  -meristems
• Stem cells can differentiate into specialised cells
• Stem cells can divide by mitosis to form more different types of cells depending in what instructions they're given
• What can adult stem cells only differentiate into

  -platelets

  -red blood cells

  -white blood cells

  (To replace those that are damaged, meaning they dont form any new tissue)
• Where are adult stem cells found

  mainly in the bone marrow but can be also be found in the skin and blood vessels
• How are adult stem cells used to treat people with diseases


  A person with a blood disease can get a bone marrow transplant. This tissue thats found inside bones have stem cells that can turn into new blood cells to replace faulty ones
• Where do adult stem cells grow

  In specific areas of the body (for example Bone marrow, intestines and hair follicles - you can‘t take adult stem cells from the intestines and grow them into blood cells for example)
• Why are embryonic stem cells and plant stem cells more useful than adult stem cells

  They can form into any type of cell
• Where are plant stem cells found

  Meristems (parts of the plant where growth occurs)
• How long can cells in the meristem tissues be able to differentiate 


  Throughout the plants entire life
• Because the plant stem cells last for the plants life it can be used to produce identical copies of whole plants quickly and cheaply
• How can rare species of plants be prevented from extinction 


  Using the plants stem cells to grow more of the same plant
• Advantages of plant stem cells


  -stops rare plant extinction

  -grow crops of identical plants that have desired features such as disease resistance for example
• How does embryonic stem cells work in medicine

  -embryo cells are extracted from early embryos

  -they are then grown in a laboratory

  -they are stimulated to differentiate into the specific cell needed

  -they are given to patients with faulty cells
• Conditions that are caused by faulty cells


  -Type 1 diabetes (can give insulin-producing cells-embryonic)

  -paralysed by spinal injuries (can give nerve cells-embryonic)
• What are common problems people are most concerned about with embryonic stem cells being used for a patient

  -Limited suply of embryonic stem cells

  -ethical, social, clinical issues

  -body may reject and destroy these cells (medication may not always stop rejection)

  -possible virus transmission

  -possible tumour development

  -embryos have potential for human life
• Which 2 stem cells can be grown in a laboratory to produce clones (genetically identical cells)


  -embryonic stem cells

  -adult stem cells
• An advantage of cloning


  they’re designed to differentiate and to become specialised for medicine and research
• Where are stem cells found

  In early human embryos
• Adult stem cells can only differentiate into related cell types - for example bone marrow can only differentiate into blood cells and cells of the immune system (the role of the immune system is to prevent disease)
• How can an embryo be made to have the same genetic information as the patient


  By therapeutic cloning
• How could you find a way to not let the stem cells be rejected by a patients body


  The stem cells produced in therapeutic cloning would contain the same genes so they wouldnt be rejected by the patients body if they need to replace faulty cells
• What is a risk of a stem cell being grown in a laboratory 


  Stem cells could become contaminated with a virus which could be passed on to the parient and make them sicker
• Why might some people be against stem cell research

  -embryos have potential human life

  -if the unwanted embryonic stem cells weren’t used from fertility clinics they would probably be destroyed (this if why some may disagree with IVF and abortion)

  -some may want people to find other sources of stem cells instead of having to use embryos

  -some countries ban stem cell research but in the uk it follows strict guidelines
• What is a multicellular organism 


  Organisms that are made from more than one cell
• What is the process called through which specialised cells form?

  Differentiation
• How many specialised cell types are there in the human body?

  About 250
• What happens to daughter cells produced by a specialised cell that can divide by mitosis?

  They will be the same type of specialised cell
• What are stem cells capable of doing?

  They can divide and give rise to many more cells of the same type
• Where are embryonic stem cells found?

  On the inside layer of an embryo
• What is the potential of embryonic stem cells?

  They can differentiate into all the different types of specialised cells
• What is the source of adult stem cells?

  Bone marrow
• What types of cells can adult stem cells mainly produce?

  Mainly cells of the blood
• What is the role of meristem cells in plants?

  They can differentiate into the cells needed by the plant in growing regions
• How do meristem cells in roots contribute to plant growth?

  They can differentiate into root hair cells and other necessary cells
• What is the significance of embryonic stem cells in development?

  They help to form all the different tissues and organs needed during development
• What is the primary function of adult stem cells?

  To replace cells lost through damage or to produce new cells for growth
• What can stem cells from the umbilical cord blood differentiate into?

  Cells of the blood, muscle, and nerve tissue
• What is the potential of meristem cells in plants?

  They can differentiate into any type of plant cell throughout the life of the plant