Unit 1 : Stem Cells

Question 1

An embryo contains only a few unspecialised cells. What are these called?

Answer 1

Stem cells

Question 2

What are stem cells?

Answer 2

Simple undifferentiated cells

Question 3

What can stem cells do?

Answer 3

• continue dividing by cell division to produce more stem cells
• differentiate into a wide varity of specialised cell types

Question 4

What are ‘embryonic stem cells’?

Answer 4

undifferentiated cells found in very early animal embryos and can form any cell type.

Question 5

Where can embryonic stem cells be sourced from?

Answer 5

early embryos, umbilical cord and placenta.

Question 6

What is an advantage of embryonic stem cells?

Answer 6

They grow rapidly and ae easy to culture.

Question 7

What are adult stem cells?

Answer 7

Unspecialised cells found in certain organs in adults - bone marrow, blood, heart tissue.

Question 8

What is a disadvantage of adult stem cells?

Answer 8

They are more difficult to grow and culture.

Question 9

Where are ‘plant stem celss’ found?

Answer 9

In the APICAL growing points or MERISTEMS at the end of the shoots and the roots.

Question 10

What is meant by ‘redifferentiate’?

Answer 10

Under certain conditions the specialisation of plant stem cells can be reversed. This allows scientists to produce large numbers of genetically identical plants in a very short time.

Question 11

Which blood cancer can stem cells be used to treat?

Answer 11

Leukaemia

Question 12

Ste cells can be used to produce new nervous tissue. What can this treat?

Answer 12

To treat Parkinson’s disease or paralysis due to spinal injuries.

Question 13

How can stem cells help repair danaged joints?

Answer 13

To build new bone, tissue or cartilage.

Question 14

How can they fight disease?

Answer 14

Stem cells can produce new immune cells which can fight disease.

Question 15

How can stem cells be used in organ transplants?

Answer 15

To produce replacememt organs that match the patient’s tissue type, to stop organ rejection.

Question 16

Fill in the gaps in the flow chart to explain how stem cells are used to treat leukaemia:
______ and _______ destroy cancerous blood cells in the patient.

Answer 16

Chemotherapy and radiotherapy

Question 17

The patient’s _______ ________
stops producing new blood cells.

Answer 17

Bone marrow

Question 18

Patient is given a transplant of bone marrow containing _______ _________ from a healthy matching donor.

Answer 18

Stem cells

Question 19

Donor stem celss multiply and produce healthy _______ _______ in the patient.

Answer 19

Blood cellls

Question 20

Chemotherapy and radiotherapy destroy patients white blood cells before the stem cell transplant. Hoe does this make the patient very vunerable?

Answer 20

It leaves the patient with no immune system.

Question 21

Stem stills are at risk of dividing in an uncontrolled way. What can this cause?

Answer 21

it may cause tumours or unwanted cell types.

Question 22

What ethical issues surround the use of stem cells?

Answer 22

• use of embryo in this way may be considered murder by some
• human rights of embryo are ignored
• religous grounds, feel that scientists are ‘playing God’
• may lead to cloning and designer babies