| Group of protozoans | Example | ||
| A. | Amoeboid | P. | Entamoeba |
| B. | Flagellated | Q. | Paramecium |
| C. | Ciliated | R. | Trypanosoma |
| D. | Sporozoan | S. | Plasmodium |
| A | B | C | D | |
| 1. | Q | S | P | R |
| 2. | S | Q | R | P |
| 3. | P | R | Q | S |
| 4. | R | P | S | Q |
| 1. | They are most abundant bacteria in nature |
| 2. | Many of them are important decomposers |
| 3. | They play a great role in recycling nutrients like nitrogen, phosphorus, iron and sulphur |
| 4. | They are helpful in making curd from milk, production of antibiotics, fixing nitrogen in legume roots, etc. |
| 1. | The two overlapping shells of cell wall fit together as in a soap box. |
| 2. | They are the chief ‘producers’ in the oceans. |
| 3. | Their cell walls are embedded with silica. |
| 4. | Diatoms behave like heterotrophs when deprived of sunlight. |