Photosynthesis, Respiration and Nutrition in Plants 

16. Which process allows plants to convert nitrogen gas into usable forms?

a) Photosynthesis

b) Assimilation

c) Nitrogen fixation

d) Transpiration

17. Which of the following nutrients is necessary for chlorophyll production in plants?

a) Iron

b) Potassium

c) Phosphorus

d) Calcium

18. Plants obtain the majority of their water through their:

a) Stems

b) Leaves

c) Flowers

d) Roots

19. The process by which plants release excess water vapor through small openings in their leaves is called:

a) Transpiration

b) Osmosis

c) Absorption

d) Assimilation

20. Which of the following is NOT a macronutrient essential for plant growth?

a) Calcium

b) Potassium

c) Nitrogen

d) Zinc