Question

The elements which are required by sea plants
A. Cobalt
B. Zinc
C. Copper
D. Sodium

Answer 1

Hint: Sea plants are generally found in marine water.
Seawater has a high concentration of salt. The main component of salt is sodium and chlorine. The chemical name of salt is sodium chloride.

Complete answer: The most abundant element in seawater is sodium because -
1. Sodium maintains the osmotic pressure of the plant cells.
2. Sodium is also needed to antagonize the toxic actions of the other salts that are present in the solution. It was shown in some experiments.
The experiments are performed by the scientist WJV Oosterhout in 1912.
3. All other elements that are cobalt, zinc, and copper are not required by sea plants.

Other uses of sodium in animal bodies are as follows:
Sodium is an example of both an electrolyte and mineral.
It helps to keep the water i.e. it helps to maintain the amount of fluid inside and outside the cell of the body's and it also helps to keep the electrolyte balance of the cells of the body.

So, the correct answer is option D. Sodium.

Note: Sodium is also essential for the nerve cells and muscle cells to perform. About 85 % of the sodium is found in blood and lymph fluid in the body.