| 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. |
| Column I | Column II | ||
| A | Branchiostoma | P | Notochord persisting in adult |
| B | Ascidia | Q | Notochord present only in larval tail |
| C | Pristis | R | Cartilaginous endoskeleton |
| D | Catla | S | Bone endoskeleton |
| A | B | C | D | |
| 1. | P | Q | R | S |
| 2. | P | Q | S | R |
| 3. | Q | P | R | S |
| 4. | Q | P | S | R |
| I: | are marine but migrate for spawning to fresh water. |
| II: | die within a few days of spawning. |
| Column I | Column II | ||
| A | Limulus | P | Gregarious pest |
| B | Locusta | Q | Living fossil |
| C | Ancylostoma | R | Filaria worm |
| D | Wuchereria | S | Hookworm |
| A | B | C | D | |
| 1. | Q | P | S | R |
| 2. | P | Q | S | R |
| 3. | P | Q | R | S |
| 4. | Q | P | R | S |
| 1. | Skin is moist and without scales. |
| 2. | A tympanum represents the ear. |
| 3. | Eyes lack eyelids. |
| 4. | Heart is three chambered. |