Answer:
Magnesium, calcium, phosphorous, sulfur these are essential nutrients for plants. These are required in trace quantity but are very important for plant life. Point A. will be correct answer.
Explanation:
As in B. starch n cellulose are composed of only carbon, oxygen and hydrogen.
As in C. These elements are not required on special occasion but are necessary throughout plant life.
As in D. C H N O is the primary component plants need but these secondary nutrients are equally necessary for growth n structure of plant.
<u><em>So answer A. Is the correct option.</em></u>
Calcium plays the most important role in structure formation of plants. Also act as messenger molecule in signaling. Deficiency of calcium caused wilting , weakened stem and ultimately death of plant.
Magnesium is the key element in chlorophyll molecule. It is necessary for chlorophyll formation.
Sulfur is another very important element in plant life, it is necessary for protein synthesis in plants.
Phosphorous plays an important role in process of cell devision , photosynthesis and respiration.
Potassium is very crucial in gaseous exchange ,it operates the opening and closing of stomata.
Explanation:
Catalase test demonstrate the presence of an enzyme called catalase, that catalyses the release of oxygen from hydrogen peroxide. It is used to tell the difference between the non-catalase producing bacteria from those bacteria that produces an enzyme catalase. Catalase is produced by the bacteria that respire using oxygen. If an organism produces catalase, bubbles of oxygen are produced when hydrogen peroxide is added to it.
The answer is B. By polluting near by streams with pesticides and herbicides
It would be best to ask a professional on the subject.