Stem cells

Question 1

What are “stem cells”?

Answer 1

• Stem cells are unspecialised cells that have the potential to change into many other cell types.

Question 2

What 2 types of stem cells are there?

Answer 2

• Adult stem cells
• Embryonic stem cells

Question 3

What 2 processes can a stem cell undergo?

Answer 3

• Replication
• Differentiation

Question 4

How does a stem cell know whether it should replicate or differentiate?

Answer 4

• Depends on instructions given to cell.

Question 5

How does a stem cell know what cell it should differentiate into?

Answer 5

• Depends on instructions given to cell.

Question 6

What is the issue with using donor organs?

Answer 6

• Donor organ doesn’t have same antigens.
• Immunosuppressants need to be used: harmful to patient.

Question 7

What are the 3 advantages of using a patient’s adult stem cells to replace faulty cells?

Answer 7

• It won’t be rejected by the patient’s body.
• Quick recovery
• Reliable (used for many years. )

Question 8

What is the disadvantage of using a patient’s adult stem cells to replace faulty cells?

Answer 8

• They are multipotent (can only change into certain types of cells.)
• Extract from bone marrow = tres painful
• Cancer/ viral infections

Question 9

What does “multipotent” mean?

Answer 9

• Multipotent: can only become limited types of cells.

Question 10

What are the 3 advantages of using a embryonic stem cells to replace faulty cells?

Answer 10

• They are “pluripotent” - can differentiate into any type of cell.
• Painless
• Treats many diseases

Question 11

What are the diadvantages of using a embryonic stem cells to replace faulty cells?

Answer 11

• Religious and ethical issues
• Viral infections
• Potential tumour

Question 12

What is meant by “therapeutic cloning?”

Answer 12

In therapeutic cloning an embryo is produced with the same genes as
the patient. Stem cells from the embryo are not rejected by the patient’s
body so they may be used for medical treatment.

Question 13

What is the significance of “therapeutic cloning?”

Answer 13

• Embryo won’t be rejected by body.
• Embryo can change into any type of cell.

Question 14

Why isn’t the embryonic cell rejected by the patient’s body in “therapeutic cloning”?

Answer 14

• The adult cell genetic info instructs the cell to produce the same antigens as body.

Question 15

What is the difference between plants and animals in differentiation?

Answer 15

• Most types of animal cell differentiate at an early stage.
• Many types of plant cells retain the ability to differentiate throughout
life.

Question 16

What is “meristem tissue”?

Answer 16

• Meristem is made up of unspecialised cells that can change into any type of cell.

Question 17

What is the plant’s version of embryonic stem cells known as?

Answer 17

• Meristem cells.

Question 18

Where are “adult stem cells” found?

Answer 18

• Adult stem cells are found in bone marrow.

Question 19

What 3 conditions may stem cells be able to treat?

Answer 19

• Diabetes
• Paralysis
• Sickle cell anaemia

Question 20

Why are stem cells in meristems useful?

Answer 20

• Rare species can be cloned to proect from extinction.
• Crops with special features (ie. disease resistance) can be cloned to produce large numbers.

economical and quick

Question 21

Where are the “embryonic stem cells” used from?

Answer 21

• Embryonic stem cells are often from IVF.

Question 22

What is the FUNCTION of adult stem cells?

Answer 22

• To produce specialised cells for repair.
  ie. red and white blood cells

Question 23

Why are stem cells good to use?

Answer 23

• Avoids the need of transplant
• Avoids patient’s body rejecting organ.
• Avoids need to wait for donor

Question 24

Where are the “meristems” often found in plants?

Answer 24

• Located in the tips of shoots/ roots.

Question 25

Compare the genetic info of daughter and mother cell. Explain your reasoning.

Answer 25

- They are genetically identical because they are clones. *Produced from the mother's stem cells by mitosis*

Question 26

What happens during cell differentiation?

Answer 26

As a cell differentiates it acquires different** sub-cellular structures** to enable it to carry out a certain function. It has become a **specialised cell.**

Question 27

What is cell division restricted to in mature animal cells?

Answer 27

- In mature animals, cell division is mainly restricted to** repair and replacement.**

Question 28

What is the difference between cell differentiation in plants vs animals?

Answer 28

* Most types of animal cell differentiate at an early stage. * Many types of plant cells retain the ability to differentiate throughout life.

Question 29

How do stem cells make clones?

Answer 29

- Stem cells make clones by dividing by mitosis.

Question 30

How would diabetes be treated by using stem cells?

Answer 30

- Allow cells to divide and grow. - Transplant new pancreas.