Question

Which of the following have species that can establish a symbiotic relationship with other organisms?

1. Cnidarians 
2. Fungi
3. Protozoa

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer 1

Correct option is (d) 1, 2 and 3

Some organisms live together and share both shelter and nutrients. This relationship is called symbiosis. 

Statement 1 is correct. Cnidaria is an invertebrate phylum which often involves in a symbiotic relation with the unicellular dinoflagellate algae, called zooxanthellae. 

Statement 2 is correct. Certain fungi live inside the roots of plants. The plants provide nutrients to the fungus and, in return, the fungus provides water and certain nutrients. Fungi also lives in a symbiotic relation with algae as a lichen. 

Statement 3 is correct. Protozoa also forms symbiotic relations with other organisms. Symbiosis in protozoa mostly represents: 

•  a close mutualistic association between a protozoan and unicellular symbiont (like bacteria, cyanobacteria or/and unicellular algae) or  

• protozoans and a multicellular organism (ruminants, lower termites, wood-eating cockroaches, plants)