Module 3

Question 1

Why do single celled organisms not need specialist exchange systems?

Answer 1

Substances can diffuse directly across the cell membrane

Question 2

3 reasons multi-cellular organisms need a specialist exchange system

Answer 2

Some cells deep within the body, low surface area to volume ratio, higher metabolic rates

Question 3

3 special features of exchange surfaces

Answer 3

Large surface area, they’re thin, good blood supply

Question 4

List the structures from the trachea to alveoli in size order large to small

Answer 4

Trachea, bronchi, bronchioles, alveoli

Question 5

Function of goblet cells

Answer 5

Secrete mucus that traps microorganisms and dust particles

Question 6

Function of cilia

Answer 6

Beat mucus secreted by goblet cell, moving the mucus towards the throat

Question 7

What is the function of elastic fibres?

Answer 7

They recoil to help push air out while exhaling

Question 8

What is the function of smooth muscle?

Answer 8

Allows for diameter of bronchi, trachea and bronchioles to be controlled

Question 9

Function of cartilage

Answer 9

Provide support for the trachea and bronchi