Question

Match the following list of animals with their level of organisation:

p. Organ level	i. Pheretima
q. Cellular level	ii. Fasciola
r. Tissue level	iii. Spongilla
s. Organ system level	iv. Obelia

• A. i-B, ii-C, iii-D, and iv-A
• B. i-B, ii-D, iii-C, and iv-A
• C. i-D, ii-A, iii-B, and iv-C
• D. i-A, ii-D, iii-C, and iv-B

Answer 1

The correct option is C

i-D, ii-A, iii-B, and iv-C

Depending on the level of organisation in the body, animals are classified. Spongilla belongs to Phylum Porifera (sponges), all the organisms of which exhibit cellular level of organisation. Obelia belongs to Phylum Cnidaria, which generally exhibits tissue level of organisation. Fasciola is a flatworm (Phylum Platyhelminthes) and shows organ level of organisation. Pheretima (earthworm) belongs to Phylum Annelida. These animals are more complex than the lower invertebrates, and exhibit organ system level of organisation.