Question

In a taxonomy, the first step is
A. Identification
B. Nomenclature
C. Classification
D. None of the above

Answer 1

Hint: Hydrilla is an aquatic plant. It uses carbon dioxide and water for photosynthesis. Oxygen is a byproduct of the process of photosynthesis and is evolved by green plants as a waste product. Sodium bicarbonate is an ingredient of baking soda. It reacts with the carbon dioxide present in water.

Complete answer:
Hydrilla being a green plant uses carbon dioxide in water for photosynthesis and releases oxygen back into the surroundings as an end product. On adding a pinch of sodium bicarbonate to the water, the sodium bicarbonate dissociates to release sodium ions and bicarbonate ions in the water. This bicarbonate ion reacts with water to form carbonic acid. This carbonic acid breaks into water and carbon dioxide. Due to this release of carbon dioxide, the availability of carbon dioxide in the water increases. This increases the rate of photosynthesis. Due to increased photosynthesis, the oxygen released into the water increases. Thus both the rate of photosynthesis and oxygen evolution increases. The sodium ions also react with water to form sodium hydroxide which is an alkali.

So, the correct answer is option A.

Note:
Sodium bicarbonate is also used as a disinfectant to clean water because it reacts with the carbon dioxide in water as in traps it thus clearing the water of it. Sodium bicarbonate is also used as an antacid because on reacting with carbon dioxide and water, it produces sodium hydroxide which has an alkalizing effect. Hydrilla is the most favorite plant for doing experiments. Hydrilla is usually used for experimentation because it is small in size and thus easier to handle.