Cell Biology- Transport

Question 1

Diffusion is the _______ movement of particles from a ____ concentration to a ___ concentration.

Answer 1

Diffusion is the passive movement of particles from a high concentration to a low concentration.

Question 2

Rate of diffusion can be changed by altering _____________ gradient, ___________ and surface ____.

Answer 2

Rate of diffusion can be changed by altering concentration gradient, temperature and surface area.

Question 3

For _____________ organisms, surfaces and organ systems are specialised for __________ __________.

Answer 3

For multicellular organisms, surfaces and organ systems are specialised for exchanging materials.

Question 4

The effectiveness of an exchange surface is increased by :
- having a _____ surface area
- having a ____ membrane
- having an _________ blood supply (in _______)
- being __________ (in animals for ___ exchange)

Answer 4

The effectiveness of an exchange surface is increased by :
- having a large surface area
- having a thin membrane
- having an efficient blood supply (in animals)
- being ventilated (in animals for gas exchange)

Question 5

Osmosis is the _______ movement of water from an area of ______ water concentration to an area of _____ water concentration, across a _________ __________ membrane.

Answer 5

Osmosis is the passive movement of water from an area of higher water concentration to an area of lower water concentration, across a partially permeable membrane.

Question 6

____ changes are caused by the movement of water across a plant cell membrane.

Answer 6

Mass changes are caused by the movement of water across a plant cell membrane.

Question 7

Active transport uses energy from ___________, to transport substances across a
membrane from ___ concentration to ____ concentration.

Answer 7

Active transport uses energy from respiration, to transport substances across a
membrane from low concentration to high concentration.

Question 8

Active transport is used in ____ ____ _____ and the _____ _________ for the __________ of
nutrients.

Answer 8

Active transport is used in root hair cells and the small intestine for the absorption of
nutrients.

Question 9

how do you calculate the surface area:volume ratio

Answer 9

imagine you have a cube each side is 1mm long.
surface area of each side = 1mm x 1mm = 1mm^2
total surface area = 1mm^2 x 6 = 6mm^2
volume = 1mm x 1mm x 1mm = 1mm^3

sa:v = 6:1

Question 10

what happens to surface area:volume ratio as an organism increases

Answer 10

it falls sharply

Question 11

explain how fish are adapted for sa:v ratio

Answer 11

the oxygen rich water passes into the mouth. It then flows over the gills, where the oxygen is transported into the bloodstream

Question 12

what are gills covered in

Answer 12

filaments

Question 13

what are the 3 adaptations of the filaments

Answer 13

• large surface area
• thin membrane for a short diffusion pathway
• efficient blood supply

Question 14

required practical - osmosis

Answer 14

1. peel the potatoes
2. use a cork borer to produce the same sized cylinders
3. use a scalpel to make cylinders the same length (3cm)
4. measure the length using a ruler and the mass using a balance
5. add 10cm^3 of a 0.5 molar sugar solution into the first test tube
   then 10cm^3 of a 0.25 molar to the second test tube
   then 10cm^3 of distilled water to the third
6. leave potatoe cylinders overnight
7. remove and dry using a paper towel - just remove surface water
8. re measure the length and mass

Question 15

how do you calculate the percentage change

Answer 15

change in value / original value x 100