Chapter 3: Exchange Surfaces

Question 1

What do larger organisms need to exchange materials?

Answer 1

Transport systems

Question 2

What are the characteristics of fish gills?

Answer 2

Large surface area,
Short diffusion path,
Ventilated,
Vascularised,
Countercurrent

Question 3

Why can’t larger organisms rely on body surfaces to exchange materials?

Answer 3

The surface area relative to volume is insufficient for exchange - distance is too big

Question 4

Name the characteristics of a body surface

Answer 4

Large surface area, short distance (0.5mm)

Question 5

What are the characteristics of the lungs (in terms of exchange surfaces)

Answer 5

Large surface area,
Alveoli,
Alveolar wall is squamous epithelium

Question 6

What are the characteristics of a leaf (in terms of an exchange surface)?

Answer 6

Internally larger surface area,
thin - short diffusion path,
permeable,
photosynthesis maintains gradient

Question 7

What are the characteristics of tadpole gills?

Answer 7

External,
Highly branched,
Short diffusion path,
Vascularised,
Movement provides water current

Question 8

What do small organisms rely on for the supply and removal of materials?

Answer 8

Diffusion across body surface

Question 9

What are the characteristics of root hairs?

Answer 9

Large surface area,
Concentration gradient maintained by active transport

Question 10

What are the characteristics of the small intestine (in terms of exchange surfaces)

Answer 10

Large surface area (villi, microvilli)
Epithelium = 1 cell thick,
vascularised,
Replenishes absorbed nutrients

Question 11

Define ‘vascularised’

Answer 11

To provide a structure (tissue) with vessels eg. blood vessels