16. Which one of the following nutrients is a structural component of the cell wall of plants?
17. The Cell Sap is –
A. a dilute solution of minerals and some organic substances in the vacuole
B. a dilute solution of minerals in water absorbed by the plant from the soil
C. a solution of different organic substances dissolved in the cytoplasm
D. exudate from the cell
18. The widely used antibiotic penicillin is produced by –
A. An Algae
B. A bacterium
C. A fungus
D. None of these
19. Which of the following is not a micronutrient for a plant?
20. Which of the following is the product of the dark reaction of photosynthesis?