Gas exchange

Question 1

Single-celled organisms and gas exchange

Answer 1

can exchange oxygen and carbon dioxide directly through their plasma membrane via diffusion

Question 2

Smaller Insects and gas exchange

Answer 2

Insects exchange gas in their tracheal system. 1. Air enters via spiracles, 2. travels through the trachea and tracheoles, delivering oxygen directly to every tissue. 3. Tracheal fluid limits diffusion to cells

Question 3

Larger Insects and gas exchange

Answer 3

same as smaller insects and… also ventilate by the movement of the abdomen, flight muscles changing the volume of the thorax and the presence of air sacs.

Question 4

Gas exchange in fish

Answer 4

They ventilate their gills by a buccal-opercular pump The orientation of the gill filaments and lamellae ensure that the water flowing over them moves in the opposite direction to the flow of blood through the capillaries (countercurrent flow), maintaining a diffusion gradient.

Question 5

nice fishy diagram

Answer 5

see photo

Question 6

Gill lamellae diagram

Answer 6

see photo