Which of the following have species that can establish symbiotic relationship with other organisms?1.Cnidarians2.Fungi3.ProtozoaSelect the correct answer using the code given below

1. A

   1 and 2 only

   1 and 2 only. Protozoa also form symbioses (e.g. termite gut, coral?).

2. B

   2 and 3 only

   2 and 3 only. Cnidarians (coral–zooxanthellae) too.

3. C

   1 and 3 only

   1 and 3 only. Fungi (mycorrhiza, lichen) too.

4. D

   1, 2 and 3

   All three. Coral, lichen/mycorrhiza, and protozoan endosymbionts.

Summary. Official key is (d) 1, 2 and 3. Cnidarians (coral and algae), fungi (mycorrhiza, lichen) and protozoa (gut and aquatic symbionts) all form symbiotic ties.