| I: | Four pairs of gills covered by an operculum on each side | 
| II: | Skin covered with placoid scales | 
| III: | Regulation of buoyancy by an air bladder | 
| 1. | marine bony fish | 
| 2. | fresh water bony fish | 
| 3. | cartilaginous fish | 
| 4. | limbless amphibian | 
| I: | Annelids are metamerically segmented animals with a true coelom. | 
| II: | Arthropods are the most abundant group of animals characterised by the presence of jointed appendages. | 
| III: | Molluscs have a soft body surrounded by an external calcareous shell. | 
| IV: | Echinoderms possess a spiny skin. | 
| V: | Hemichordates are fresh water animals. | 
| 1. | 2 | 2. | 3 | 
| 3. | 4 | 4. | 5 | 
| I: | possess a jaw | 
| II: | have a cartilaginous endoskeleton | 
| 1. | Only I is correct | 
| 2. | Only II is correct | 
| 3. | Both I and II are correct | 
| 4. | Both I and II are incorrect | 
| Assertion (A): | The digestive system in Platyhelminthes is called incomplete. | 
| Reason (R): | Platyhelminthes are mostly endoparasites found in animals including human beings. | 
| 1. | (A) is True but (R) is False. | 
| 2. | Both (A) and (R) are True and (R) is the correct explanation of (A). | 
| 3. | Both (A) and (R) are True but (R) is not the correct explanation of (A). | 
| 4. | (A) is False but (R) is True. | 
| 1. | radially symmetrical, triploblastic and pseudocoelomate animals. | 
| 2. | bilaterally symmetrical, triploblastic and acoelomate animals. | 
| 3. | bilaterally symmetrical, triploblastic and pseudocoelomate animals. | 
| 4. | radially symmetrical, diploblastic and eucoelomate animals. | 
| 1. | Arthropods | 2. | Hemichordates | 
| 3. | Most molluscs | 4. | Annelids | 
| I: | They are exclusively marine. | 
| II: | They have cellular level of organisation. | 
| III: | They have a water vascular system with tube feet. | 
| IV: | Digestion is intracellular. | 
| V: | Fertilisation is external and development is direct. |