Unit 1 Differentiation

Question 1

Define differentiation

Answer 1

Is the process by which all a cell expresses certain genes to produce proteins that are characteristics for that type of cell

Question 2

Why is differentiation important in multicellular organism

Answer 2

Having cells that are specialised and carry out specific functions in the cell allows for the “division of labour” in larger more complex organisms

Question 3

How is a muscle cell different from that of a fat cell in terms of Gene expression

Answer 3

A muscle cell will have different genes switched on and off compared to that of a fat cell. Therefore it will produce different proteins

Question 4

How do we define a stem cell

Answer 4

Stem cells are unspecialised cells that have the ability to self renew and differentiate

Question 5

What two processes can be carried out by all stem cells

Answer 5

Self renewal

Differentiation

Question 6

Where are unspecialised cells found in plants

Answer 6

Meristems

Question 7

What are the two types of stem cells found in humans

Answer 7

Embryonic and adult tissue

Question 8

Describe a tissue stem cell

Answer 8

Found in all tissues throughout the body and are involved in growth repair and renewal of cells
Multi potent= differentiate into a narrow range of cells found in the tissue

Question 9

Two places you might find tissue stem cells

Answer 9

Skin

Bone marrow

Question 10

Describe embryonic stem cells

Answer 10

Taken from the inner cell mass of a blastocyst- an early embryonic stage before implantation begins
Pluripotent= all genes have the ability to be switched on so it can differentiate into any type of cell

Question 11

Where do we find embryonic cells in the body

Answer 11

Blastocyst

Question 12

Difference between embryonic and tissue stem cells

Answer 12

Embryonic=pluripotent, genes have the ability to be switched on and can become any type of cell
Tissue= multi potent, only specific genes can be turned on/ can only become a narrow range of cells found in the tissue

Question 13

Describe a therapeutic use of stem cells

Answer 13

Can be used to treat damaged or disease tissues or organs

Question 14

Describe a research purpose of stem cells

Answer 14

Can be used as a model cell to investigate how diseases develop
Or can be used to test responses of cells to new drugs

Question 15

Give two arguments for using embryonic stem cells

Answer 15

Uses embryos left over from IVF so the eggs where going to be discarded anyways
Embryonic stem cells have the ability to benefit humanity

Question 16

Give two arguments against using embryonic stem cells

Answer 16

A fertilised egg had a soul/ is a life

Human life starts at conception so can be considered murder

Question 17

Uses of non coding sequences/ regulating transcription steps

Answer 17

RNA polymerase needs the assistance of transcription factors such as activators to stay transcription
Activators bond to the non coding regulator sequences of DNA

Question 18

Uses of non coding sequences/ coding for translated RNA steps

Answer 18

tRNA and rRNA are coded for by no. Coding DNA

Both have specific functions but aren’t translated into proteins

Question 19

Uses of non coding sequences/ protection

Answer 19

Some non coding sequences make up protective structures called teromeres at the end of chromosomes

Question 20

Define the genome

Answer 20

The genome of an organism is its entire hereditary information encoded in DNA

Question 21

What is the human genome made up of

Answer 21

Made up of genes which code for proteins and other DNA sequences which don’t code for proteins

Question 22

Which for of RNA is transcribed and translated

Answer 22

mRNA