Breathing is not respiration
Cellular respiration is invisible, but in some animals it can be observed happening through their breathing movements.
The action carried out to take the oxygen that cellular respiration needs into the cells, and to expel the carbon dioxide produced there, is breathing. It is not respiration — it is what supplies respiration with its gases.
Assignment 8.3
For the animals below, what movements does the body make for respiration, or what processes are connected with it?
- Frog
- Japanese koi carp
- Human being
- Whale
- Dog
- Grasshopper
What to look for
Ask three questions about each animal: which organ the gas enters through, what movement carries it in and out, and whether that movement is visible from outside.
For a human, say: the lungs, the movement of the ribs and diaphragm, and yes — the chest rising and falling can be seen. For a koi carp all three answers are different.
The common error
Writing "fish respire through their gills" is wrong. What the gills do is obtain the oxygen dissolved in the water — the respiring happens in every cell that oxygen reaches.