There are _________ hypothesis which may explain opening and closing of stomata?
Correct answer: B. Two
- A. One
- B. Two
- C. Three
- D. Four
Explanation
The two commonly taught explanations for stomatal movement are the starch-sugar hypothesis and the potassium-ion hypothesis. Both explain how changes in guard-cell solutes alter water entry and turgor, producing opening or closing. Students may choose three by counting light, CO2 and water stress as separate hypotheses, but these are factors or signals rather than the main hypotheses.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Biological Importance of Water
Water supports life through its polarity, hydrogen bonding and ability to dissolve ionic and polar substances. Its high specific heat, heat of vaporization, cohesion, adhesion and incompressibility help regulate temperature, transport materials and maintain structure, while hydrolysis and osmosis depend directly on water.
Practise Biological Molecules
1,790 free Biological Molecules MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Biological Importance of Water questions
Low level of CO2 favours _________ of the stomata.
Symbionts which help plants in uptake of phosphorous and trace metals such as zinc and copper.
Addition of salts and other solutes from other cells into xylem sap, __________ the water potential of the xylem sap
The opening and closing of stomata is directly controlled by the___________?
___________ function as multisensory hydraulic valve?
Stomatal transpiration is __________ of total transpiration