6.5 - Stem Cells

Question 1

What are stem cells? Why would they be needed?

Answer 1

Stem cells are undifferentiated cells that have the potential to differentiate into various specialized cell types. They are capable of repeated division to generate new cells for growth, repair, and tissue maintenance.

Question 2

What is the difference between stem cells and differentiated cells?

Answer 2

Stem cells are unspecialized and can differentiate into various types of cells, while differentiated cells are specialized to perform specific functions and have lost the ability to divide.

Question 3

What is potency in stem cells?

Answer 3

Potency refers to the ability of a stem cell to differentiate into various types of cells. The more types of cells a stem cell can become, the higher its potency.

Question 4

What is a totipotent stem cell?

Answer 4

Totipotent stem cells can differentiate into any cell type, including all embryonic tissues and extra-embryonic tissues (like the placenta). A fertilized egg and the first few divisions of the zygote are totipotent.

Question 5

What is a pluripotent stem cell? Where are they found?

Answer 5

Pluripotent stem cells can differentiate into any cell type within an organism, but not extra-embryonic tissues. These cells are found in early embryos and can form all the tissues in the body.

Question 6

What is a multipotent stem cell?

Answer 6

Multipotent stem cells can differentiate into a limited range of cell types, usually within a specific tissue type. An example is hematopoietic stem cells, which give rise to different blood cells.

Question 7

What are the 3 sources of animal stem cells?

Answer 7

1. embryonic stem cells
2. adult stem cells
3. umbilical cord stem cells

Question 8

Where are embryonic stem cells found? What type of cells are they?

Answer 8

These are totipotent or pluripotent cells found in early embryos.

Question 9

Where are adult stem cells found? What type of cells are they? What can the be used for?

Answer 9

These multipotent cells are found in specific tissues, such as bone marrow and can be used for tissue repair.

Question 10

Where are the umbilical cord stem cells found? What type of cells are they?

Answer 10

These are collected from the umbilical cord at birth and are a rich source of multipotent cells.

Question 11

What are induced pluripotent stem cells (iPSCs)?

Answer 11

iPSCs are adult cells that have been genetically reprogrammed to become pluripotent. They can differentiate into many types of cells, similar to embryonic stem cells, but without using embryos.

Question 12

What are the sources of plant stem cells?

Answer 12

Stem cells in plants are found in meristematic tissue, such as the apical meristems at the tips of roots and shoots, as well as the vascular cambium between xylem and phloem tissues.

Question 13

What are some medical uses of stem cells?

Answer 13

Treats:
1. Heart Disease
2. Type 1 Diabetes
3. Parkinson’s disease
4. Alzheimer’s disease
5. Macular Degeneration
6. Spinal injuries

Question 14

How can stem cells be used to treat: Heart Disease?

Answer 14

Stem cells may help regenerate heart muscle damaged after a heart attack.

Question 15

How can stem cells be used to treat: Type 1 Disease?

Answer 15

Stem cells can be used to regenerate insulin-producing cells in the pancreas.

Question 16

How can stem cells be used to treat: Parkinson’s Disease?

Answer 16

Stem cells can potentially replace dopamine-producing cells lost in the disease.

Question 17

How can stem cells be used to treat: Alzheimer’s disease?

Answer 17

Stem cells could help replace brain cells lost due to abnormal protein build-up.

Question 18

How can stem cells be used to treat: Macular Degeneration?

Answer 18

Stem cells may restore vision in individuals with macular degeneration.

Question 19

How can stem cells be used to treat: Spinal Injuries?

Answer 19

Stem cell therapies may help restore movement in spinal cord-injured patients.

Question 20

What are some non-medical uses of stem cells?

Answer 20

1. Burn treatment
2. Drug testing
3. Developmental biology

Question 21

How can stem cell be used for: Burn Treatment?

Answer 21

Stem cells can be used to grow new skin for burn victims.

Question 22

How can stem cell be used for: Drug Testing?

Answer 22

New drugs can be tested on stem cell cultures before clinical trials.

Question 23

How can stem cell be used for: Developmental Biology?

Answer 23

Stem cells are used to study organism development and growth from a single fertilized cell.

Question 24

What are some challenges of using stem cells? (4)

Answer 24

1. Immune Rejection
2. Tumour Formation
3. Technical Difficulties
4. Ethical Concerns

Question 25

Why may using stem cells cause: Immune Rejection?

Answer 25

Transplanted stem cells may be recognized as foreign and attacked by the immune system.

Question 26

Why may using stem cells cause: Tumour Formation?

Answer 26

If stem cells divide uncontrollably, they can form tumors, including cancer.

Question 27

Why may using stem cells cause: Technical Difficulties?

Answer 27

Generating and maintaining stem cells in a laboratory setting is complex and requires precise conditions.

Question 28

Why may using stem cells cause: Ethical Concerns?

Answer 28

Use of embryonic stem cells raises debates about the morality of destroying embryos.

Question 29

What are some ethical issues surrounding stem cell research?

Answer 29

Ethical issues include the destruction of embryos to obtain stem cells, concerns about consent and ownership of genetic material, and religious objections to using embryonic stem cells.

Question 30

How do induced pluripotent stem cells (iPSCs) address some ethical concerns?

Answer 30

iPSCs are derived from adult cells, avoiding the destruction of embryos, which makes them less controversial compared to embryonic stem cells.

Question 31

How do stem cells function in plants?

Answer 31

Plant stem cells in meristematic tissue continue to divide and differentiate throughout the plant's life. This enables the plant to grow and form new tissues, such as vascular tissue (xylem and phloem).

Question 32

What are some uses of stem cells in plant biology?

Answer 32

Stem cells in plants are essential for growth, repair, and regeneration, especially in the formation of new tissues as the plant matures.

Question 33

How are erythrocytes (red blood cells) replaced in mammals?

Answer 33

These have a lifespan of around 120 days. They are constantly produced in bone marrow from hematopoietic stem cells at a rate of approximately 3 billion cells per kg of body mass per day.

Question 34

How are neutrophils (white blood cells) replaced in mammals?

Answer 34

These cells live for about 6 hours and are produced at a rate of 1.6 billion cells per kg per hour, with production rates increasing during infections.

Question 35

How does stem cell differentiation lead to specialized blood cells?

Answer 35

Stem cells in the bone marrow differentiate into specialized blood cells (erythrocytes, neutrophils, etc.) as they mature and lose their ability to divide, adapting to the specific functions they perform in the body.

Question 36

What are some promising areas for future stem cell research and therapies?

Answer 36

1. Regenerative Medicine 2. Cancer Treatment 3. Personalised Medicine

Question 37

Why may stem cells be used in: Regenerative Medicine?

Answer 37

Stem cells may be used to regenerate damaged tissues, such as heart muscle or nerve cells.

Question 38

Why may stem cells be used in: Cancer Treatment?

Answer 38

Stem cells could help target and treat cancers by regenerating healthy cells and replacing damaged ones.

Question 39

Why may stem cells be used in: Personalised Medicine?

Answer 39

Stem cells could be used to create tissues specific to an individual, reducing rejection in transplants.