3.2.2 Gas Exchange

Question 1

3 factors efficiency of gas exchange depends on

Answer 1

1) high surface area
2) short diffusion distance
3) high conc gradient

Question 2

In Insects, what does air enter through?

Answer 2

Spiracles

Question 3

What does oxygen travel along and how does it get into the cells?

Answer 3

02 travels down conc gradient along the trachea
The trachea are closely surrounded by cells
02 diffuses into cells

Question 4

What helps maintain a high conc gradient as oxygens diffuses into cells in insects

Answer 4

Ventilation

Question 5

How do insects prevent water loss

3 ways

Answer 5

1) Waxy cuticle covers body to reduce evaporation
2) Insects can close their spiracles
3) small insects are covered by a hard exoskeleton to prevent them drying out

Question 6

What two features in a fish have a big surface area

Answer 6

Filaments and Lamellae

Question 7

What feature do fish have which enable a short diffusion distance

Answer 7

Thin epithelium

Question 8

What is counter current in flow fish

Answer 8

Blood and water move in opposite directions which maintain a high conc gradient
Water is always next to blood with a lower conc 02
Circulation of blood replaces blood that is saturated with 02
Ventilation of water replaces water low in 02