| 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. |
| 1. | microvilli | 2. | fibrils |
| 3. | tentacles | 4. | canals |
| Statement I: | An undifferentiated layer, mesoglea, is present in between the ectoderm and the mesoderm in diploblastic organisms. |
| Statement II: | A third germinal layer, endoderm, in between the ectoderm and mesoderm, is present in triploblastic animals. |