Question

Which of the following statement is correct :
1. At night, these guard cells swell with water and become bloated, opening the stoma.
2. During the day, the guard cells release their water and the stomata close.
3. More than 97% percent of water reaching the leaves is used in plant growth and photosynthesis.
4. The rate of transpiration can be easily demonstrated by cobalt chloride paper test.

• A. All are correct
• B. Only 4 is incorrect
• C. Only 2 is incorrect
• D. Only 1 is incorrect

Answer 1

The correct option is B Only 4 is incorrect

The rate of transpiration can be easily demonstrated by cobalt chloride paper test.
During the day, these guard cells swell with water and become bloated, opening the stoma. At night, the guard cells release their water and the stomata close.
Plants use water in huge amounts, but only small part of that remains in the plant to supply growth. About 97% of water taken up by plants is lost to the atmosphere, 2% is used for volume increase or cell expansion, and 1% for metabolic processes, predominantly photosynthesis.