Unit 1 Topic 4

Question 1

What is differentiation?

Answer 1

the process by which cells or tissues undergo a change towards a more specialised function

Question 2

What are the levels of organisation in order?

Answer 2

cell -> tissues -> organs -> organ systems

Question 3

Where does growth take place in a plant

Answer 3

meristems

Question 4

what are meristems

Answer 4

regions of unspecialised cells in plants that can divide/ self-renew and/or differentiate

Question 5

what is the process by which cells divide

Answer 5

unspecialised cells divide rapidly by mitosis to differentiate and form new plant tissues

Question 6

where are apical meristems located

Answer 6

at the tips of the roots and shoots in a plant

Question 7

what meristems are located only at the tips of the roots and shoots of a plant

Answer 7

apical meristems

Question 8

what are stem cells

Answer 8

unspecialised cells

Question 9

what can stem cells do

Answer 9

self-renew
differentiate

Question 10

what special characteristics that stem cells have make them different to other body cells?

Answer 10

•undifferentiated, allowing them to divide and maintain a supply of stem cells for the body
•found in all multicellular organisms
•self-renewing and can differentiate

Question 11

what are the two types of stem cells

Answer 11

embryonic stem cells
tissue (adult) stem cells

Question 12

where are embryonic stem cells derived from?

Answer 12

embryos at the blastocyst stage

Question 13

how can embryonic stem cells be described?

Answer 13

pluripotent

Question 14

What type of stem cells are pluripotent and what does it mean?

Answer 14

embryonic stem cells
pluripotent means they can differentiate into many different types of cells

Question 15

What are tissue stem cells involved in?

Answer 15

the growth, repair and renewal of the cells found in that tissue

Question 16

How can tissue stem cells be described?

Answer 16

Multipotent

Question 17

What type of stem cells are multipotent and what does it mean

Answer 17

tissue stem cells
multipotent means they can differentiate into only certain types of cells

Question 18

where can tissue stem cells be found?

Answer 18

brain
bone marrow
peripheral blood
blood vessels
skeletal muscle
skin

Question 19

What is cellular differentiation

Answer 19

the process by which a cell develops more specialised functions by expressing the genes characteristic for that type of cell

Question 20

what is cellular differentiation the result of?

Answer 20

gene expression

Question 21

Why don’t all cells complete the process of differentiation and pause at the stage where they can still undergo duplication?

Answer 21

it allows them to generate replacement cells which may die or be damaged- it allows for growth and repair. These cells are known as tissue stem cells

Question 22

Give examples of therapeutic uses of stem cells?

Answer 22

Skin: patients with serious burns can be treated using a technique which grows new skin in the lab from skin stem cells
Blood: bone marrow transplants have been carried out for many years as a treatment for diseases such as leukaemia and other blood disorders
Cornea: corneal stem cells can be transplanted onto the diseases cornea to repair it

Question 23

What can research involving stem cells allow scientists to find out?

Answer 23

Stem cell research allows scientists to discover more info about key cell processes such as growth, differentiation and gene regulation. Stem cells can also be used to study how diseases develop. Stem cells may be a viable alternative to animals for testing new drugs in the future

Question 24

Give an ethical issue of stem cells

Answer 24

some people believe the destruction of the blastocyst is unethical

Question 25

What can stem cells be used as to study how diseases develop or being used for drug testing?

Answer 25

model cells