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 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
The respiratory quotient (RQ) of a plant is measured to be 1. Which substrate is MOST likely being primarily metabolized?
Fats
Proteins
Organic acids
Carbohydrates
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
A succulent xerophyte exhibiting Crassulacean Acid Metabolism (CAM) is kept in a sealed, transparent container with a CO2 sensor. The container is exposed to a 12-hour light/12-hour dark cycle. At which point during the cycle would the CO2 concentration within the container be LOWEST, assuming no other influencing factors?
Near the end of the light period
Near the beginning of the light period
Midway through the dark period
Near the end of the dark period
A germinating fatty seed has an R.Q. of 0.7. If the volume of CO2 released is 140 mL, what volume of O2 is consumed?
100 mL
140 mL
200 mL
280 mL
Which of the following conditions would MOST LIKELY result in an R.Q. value greater than 1 in a mammal?
Prolonged starvation
A diet consisting primarily of proteins
Intense exercise leading to lactic acid accumulation
A diet rich in fats
