6.5 - Stem Cells

Question 1

What is potency and what are the types of stem cell potency?

Answer 1

Potency: the ability to differentiate into different cell types

• Totipotent: can differentiate into any type of cell found in zygotes (the first 8-16 cells)(can form entire organisms)
• Pluripotent: can form all tissue types but not whole organisms (found in early embryos)
• Multipotent: only form a range of cells within a certain type of tissue (found in bone marrow)

Question 2

Where are all blood cells derived from?

Answer 2

Stem cells in the bone marrow

Question 3

Explain the replacement of RBCs

Answer 3

• Short lifespan of 120 days

- stem colonies in bone marrow produce 3 billion per kg of body mass per day

Question 4

Explain the replacement of Neutrophils

Answer 4

• Live for 6 hours

- Colonies of stem cells in bone marrow produce 1.6 billion per kg per hour and will increase during infection

Question 5

Where are stem cells found in plants?

Answer 5

• In the meristematic tissue (meristem)
• Is located where growth occurs in plants e.g roots and shoots
• The tissue is located sandwiched between the phloem and xylem tissues and is called the vascular cambium
• Results in differentiation into different cells present in xylem and phloem tissue, so as the plant grows, the vascular tissue grows too
• These stem cells are pluripotent

Question 6

What are the uses of Stem Cells?

Answer 6

• Heart disease
• Type 1 diabetes
• Parkinson’s disease
• Alzheimer’s disease
• Mascular degeneration
• Birth defects
• Spinal injuries
• Treatment of burns
• Drug Trials
• Developmental biology