A-Level Exchange surfaces

High Surface area to volume ratio allows cells to do what quickly?

• Move materials around inside the cell
• Move materials in and out of the cell 
• Communicate to other cells
• Divide

Which block has the smallest surface area to volume ratio?

• Green

• Pink

• Yellow

Exchanges between oganisms and their environment can take place by

• Diffusion

• Active Transport

• Osmosis

• All of the above

Find out the surface area to volume ratio for a cube with sides 2cm

• 1:3

• 3:1

• 0.33

• 2:1

lower S:A ratio...

• decreases the rate of gas exchange
• increases the rate of gas exchange
• none of the above

Which of these is NOT a feature of specialised exchange surfaces?

• large surface area relative to the volume of the organism

• very thin so that diffusion distance is short

• fully permeable to allow all materials to cross

• movement of the environmental medium (e.g. air) to maintain a diffusion gradient

• A transport system to ensure the movement of the internal medium, for example blood, in order to maintain a diffusion gradient

The flow of oxygen (in order) into the cells of an insect is

• spiracles - trachea - tracheole fluid - cells - tracheole

• spiracles - cells - trachea - tracheole - tracheole fluid

• cells - tracheole fluid - tracheole - trachea - spiracles

• spiracles - trachea - tracheole - tracheole fluid - cells

To prevent moisture loss Insects have a?

• permeable exoskeleton

• impermeable exoskeleton

Name the structure through which gases enter and leave the body of an insect.

• tracheoles

• alveoli

• spiracle

• lungs

Tubifex worms are small, thin animals that live in water. They have no specialised gas exchange or circulatory system. Name the process by which oxygen reaches the cells inside the body of a tubifex worm.

• active transport

• respiration

• diffusion

• facilitated diffusion