Prepare for NEET Biology Respiration in Plants with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert explanations of glycolysis, Krebs cycle, and more.
Which of the following statements BEST describes the relationship between photosynthesis and respiration in plants at night?
Photosynthesis and respiration both cease, maintaining a neutral balance of gases.
Photosynthesis continues at a reduced rate, while respiration increases to compensate.
Photosynthesis ceases, and respiration also ceases to conserve energy.
Photosynthesis ceases, and respiration continues, consuming stored organic molecules and releasing CO2.
The compensation point in plants is reached when...
Photosynthesis ceases entirely, and only respiration occurs.
The rate of photosynthesis equals the rate of respiration, resulting in no net gas exchange.
Respiration ceases entirely, and only photosynthesis occurs.
The plant switches from C3 to CAM photosynthesis.
Which specific adaptation allows some plants to minimize water loss while still facilitating gas exchange for respiration?
Increased leaf surface area
Absence of stomata
Continuous, high rates of transpiration
Stomatal opening primarily at night in CAM plants
If a plant's respiration rate significantly exceeds its photosynthetic rate for a prolonged period, what is the MOST likely consequence?
Increased growth and biomass
Enhanced fruit and seed production
Accumulation of starch in storage organs
Depletion of stored carbohydrates and eventual plant death
During aerobic respiration, the complete oxidation of one molecule of glucose theoretically yields 38 ATP. However, the actual yield is often lower. Which of the following is NOT a significant contributor to this reduced ATP yield?
Incomplete oxidation of glucose in the cytoplasm
Leakage of protons across the inner mitochondrial membrane
Utilization of the proton gradient for processes other than ATP synthesis
Variations in the efficiency of the electron transport chain
Which specific component of the electron transport chain is directly responsible for the reduction of oxygen to water during aerobic respiration?
NADH dehydrogenase
Succinate dehydrogenase
Cytochrome bc1 complex
Cytochrome c oxidase
If the inner mitochondrial membrane were to become permeable to protons, what would be the MOST immediate consequence on ATP synthesis?
ATP synthesis would increase due to increased proton flow.
ATP synthesis would stop because the proton gradient would dissipate.
ATP synthesis would be unaffected as it relies on substrate-level phosphorylation.
ATP synthesis would decrease, but some ATP would still be produced by glycolysis.
A researcher is studying a novel inhibitor that specifically targets the F0 subunit of ATP synthase. What is the most likely direct effect of this inhibitor on aerobic respiration?
Increased electron transport chain activity
Inhibition of proton flow through the inner mitochondrial membrane
Enhanced ATP production
Stimulation of Krebs cycle activity
Under anaerobic conditions, the regeneration of NAD+ for glycolysis is primarily achieved through:
The electron transport chain
Formation of lactate or ethanol
The Krebs cycle
Oxidative phosphorylation
In the context of aerobic respiration, uncoupling agents like 2,4-dinitrophenol (DNP) disrupt ATP synthesis by:
Inhibiting the electron transport chain
Dissipating the proton gradient across the inner mitochondrial membrane
Blocking the binding of NADH to Complex I
Inhibiting the activity of ATP synthase directly
