Stem Cells

Question 1

Stem cell:

Answer 1

An undifferentiated/unspecialised cell which an self-renew to produce more cells of the same type or
specialise to carry out a specific function

Question 2

Unspecialised cells:

Answer 2

• They can become any type ofcell
• stem cells

Question 3

Specialised cells:

Answer 3

• These cells are fixed
• They can onlydivide to make its own type of cell

Question 4

When do plant stem cells differentiate?

Answer 4

Many plant cells retain the ability to differentiate throughout their lives

Question 5

Where are plant stem cells found?

Answer 5

• Plants have layers of unspecialised stem cells in the roots and shoots
• The layers are called the meristem

Question 6

What can the meristem tissue in plant cells differentiate into?

Answer 6

Meristem tissue in plants can differentiate into any type of plant cell, throughout the life of the plant

Question 7

Why are plant stem cells useful

Answer 7

• Stem cells from meristems in plants can be used to produce clones of plants quickly and economically
• Rare species can be cloned to protect them from extinction
• Crop plants with special features such as disease
resistance can be cloned to produce large numbers of identical
plants for farmers so more crops can survive

Question 8

What are all the types of human stem cells?

Answer 8

• Embryonic stem cells
• Umbilical stem cells
• Adult stem cells
• Therapeutic stem cells (therapeutic cloning)

Question 9

Where are embryonic stem cells found?

Answer 9

Developing cells of an embryo (3-5 days old)

Question 10

What can embryonic stem cell differentiate into?

Answer 10

Any type of cell

Question 11

What are the positives of embryonic stem cells?

Answer 11

• Can differentiate into any type of cell
• [Uses ‘wasted’ embryos from
IVF]
• All types of tissues can be grown
• Replace cells that have been damaged or destroyed e.g. paralysis

Question 12

What re the negatives of embryonic stem cells?

Answer 12

• Ethical issues - destroying the embryo and therefore a chance of life
• Need to take
immunosuppressant drugs
• Technology is still developing
• Expensive

Question 13

Where are umbilical stem cells found?

Answer 13

In the umbilical cord after the birth of a child

Question 14

What can umbilical stem cells differentiate into?

Answer 14

Blood cells - often used to treat blood disorder in the child later in life

Question 15

Where are adult stem cells found?

Answer 15

most parts of the body, including brain, bone marrow, blood vessels

Question 16

What can adult stem cells differentiate into?

Answer 16

all of the cells of the adult body

Question 17

What are the negatives of adult stem cells?

Answer 17

may not be able to be manipulated to produce all cell types

Question 18

What are positives of therapeutic stem cells?

Answer 18

regenerate functional tissue and replace damaged tissue

Question 19

What can stem cells be used to treat in medicine?

Answer 19

leukemia, Hodgkin disease, non-Hodgkin lymphoma and some solid tumor cancers

Question 20

Why is therapeutic cloning less ethically wrong than destroying embryonic stem cells?

Answer 20

destruction of the generated embryos in order to collect cells that would further be differentiated in vitro

Question 21

What has led to the development of stem cell technology?

Answer 21

Embryonic stem cells were first isolated in 1981 through studies focusing primarily on murine blastocysts