Excretion and respiration in protozoa

Master Veterinary Protozoology – Notes, Case Studies & Practical Insights – with Lomash

Excretion in protozoa

Metabolic waste products in protozoa pass out either by diffusion through the body surface membrane or by means of contractile vacuole, which plays osmoregulatory function.
In case of B. coli, spiral opening called cytopyge is present through which waste materials are excreted.

Biology, Animal Structure and Function, Osmotic Regulation and Excretion, Excretion Systems | VIVA Open

Respiration

Most protozoa absorb oxygen through body surface and remove CO₂ through respiratory vacuole.