Unit 2 - Cell organisation and stem cells

Question 1

Define specialised

Answer 1

having particular structure to serve a particular function

Question 2

Why do multicellular organisms need specialised cells?

Answer 2

-complex communication in a multicellular organism
-specialised functions need specialised cells
-maximise efficiency of processes like absorbing nutrients

Question 3

What features does an red blood cell have to suit it for its function?

Answer 3

Biconcave disc- maximises SA to carry oxygen
No nucleus- more room for haemoglobin
Flexible- can squeeze through narrow capillaries

Question 4

What features does a root hair cell have to suit its function?

Answer 4

Root hairs- increase surface area to maximise uptake of water/minerals from the soil

Question 5

What features does a guard cell have to suit it for its function?

Answer 5

Cell wall thicker on inside than outside- so cell doesn’t change symmetrically as its volume changes
Gap in the centre- allows gases in and out

Question 6

What are the 4 main categories of tissues in animals?

Answer 6

Nerve tissue
epithelial tissue
muscle tissue
connective tissue

Question 7

What are stem cells?

Answer 7

Undifferentiated cells with the potential to differentiate into a variety of the specialised cell types of an organism

Question 8

What are stem cells used for in the body?

Answer 8

-growth
-development (of am embryo)
-tissue repair

Question 9

Where are stem cells found in plants?

Answer 9

Meristematic tissue (e.g roots and shoots)

Question 10

How do cells become specialised?

Answer 10

-all cells have the same DNA
-genes are switched on and off by epigenetics
-different proteins are produced in the cell
-so the cell can undergo a specialised function due to the proteins