Diatomaceous earth is used as a heat insulator in boilers and steam pipes because the cell wall of diatom is
1. Composed of iron
2. Composed of silicon dioxide
3. a good conductor of heat
4. a bad conductor of electricity
Select the wrong statement:
| 1. | The walls of diatoms are easily destructible |
| 2. | Diatomaceous earth is formed by the cell walls of diatoms |
| 3. | Diatoms are chief producers in the oceans |
| 4. | Diatoms are microscopic and float passively in water |
| 1. | Dinoflagellates | 2. | Diatoms |
| 3. | Cyanobacteria | 4. | Euglenoids |
In which group of organisms the Cell walls form two thin overlapping shells which fit together?
| 1. | Chrysophytes | 2. | Euglenoids |
| 3. | Dinoflagellates | 4. | Slime moulds |