Biology · BIOLOGICAL CLASSIFICATION

Diatoms are chief 'producers' in the oceans. What structural composition renders their cell wall indestructible, giving rise to 'diatomaceous earth'?

1. A
   Deposition of chitin and calcium carbonate
2. B
   Silica embedded in walls forming two thin overlapping shells that fit like a soap box
3. C
   Protein pellicle reinforced with peptidoglycan layers
4. D
   Thick mucilaginous sheath containing sporopollenin