Prepare for NEET Biology Photosynthesis in Higher Plants (Dark Phase) with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert insights into Calvin cycle, carbon fixation, and carbohydrate synthesis.
NEET Questions / Botany / Photosynthesis in Higher Plants / Dark Phase
In C4 plants, the initial fixation of CO2 occurs in mesophyll cells, forming a 4-carbon compound. This compound then travels to bundle sheath cells, where it releases CO2. What is the PRIMARY advantage of this spatial separation of CO2 fixation and the Calvin cycle?
Increases the efficiency of light absorption
Minimizes photorespiration by increasing CO2 concentration around RuBisCO
Reduces the need for water
Allows the plant to fix CO2 at night
During photorespiration, the oxygenation activity of the RuBisCo enzyme results in the production of:
One molecule of phosphoglycerate and one molecule of phosphoglycolate
Two molecules of phosphoglycolate
Two molecules of phosphoglycerate
One molecule of phosphoglyceraldehyde and one molecule of phosphoglycolate
In the context of photorespiration, what are the immediate products formed when RuBisCo acts as an oxygenase?
Two molecules of phosphoglycerate
One molecule of phosphoglycerate and one molecule of phosphoglycolate
Two molecules of phosphoglycolate
One molecule of phosphoglyceraldehyde and one molecule of phosphoglycolate
Which of the following correctly describes the products of RuBisCo's oxygenation activity during photorespiration?
Two molecules of phosphoglycerate
Two molecules of phosphoglycolate
One molecule of phosphoglycerate and one molecule of phosphoglycolate
One molecule of phosphoglyceraldehyde and one molecule of phosphoglycolate
RuBisCo's oxygenase activity leads to the formation of 2-phosphoglycolate, a __-carbon compound.
Two
Three
Four
Five
If RuBisCo's oxygenase activity is inhibited in a plant, which of the following processes would be directly affected?
Calvin cycle
Light-dependent reactions
Krebs cycle
Photorespiration
Given below are two statements:
Statement I: In plants, increased levels can lead to decreased fixation due to competition with RuBisCO.
Statement II: In plants, photorespiration is significantly reduced in mesophyll cells and nearly absent in bundle sheath cells.
In the light of the above statements, choose the correct answer from the options given below:
Both Statement I and Statement II are correct
Both Statement I and Statement II are incorrect
Statement I is correct but Statement II is incorrect
Statement I is incorrect but Statement II is correct
How does the presence of affect fixation in plants, and how do plants mitigate this effect?
competes with for RuBisCO in plants, reducing fixation. plants concentrate around RuBisCO in bundle sheath cells, minimizing this competition.
enhances fixation in plants. plants have no mechanism to regulate levels.
has no effect on fixation in plants. plants use PEP carboxylase to fix .
inhibits release in plants. plants store excess in mesophyll cells.
Which of the following statements accurately describes the role of bundle sheath cells in minimizing photorespiration in plants?
They maintain a high concentration around RuBisCO, minimizing its interaction with .
They actively transport out of the leaf.
They prevent from entering the leaf.
They convert into .
If a plant is exposed to high levels and shows a significant decrease in fixation, is it more likely to be a or plant? Explain your reasoning.
plant, because they are more susceptible to photorespiration at high levels.
plant, because they have a higher affinity for .
plant, because they cannot fix in the presence of .
plant, because they require high levels for efficient fixation.
