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.
A researcher observes that a plant placed in a sealed chamber shows a net decrease in CO2 levels during the day but a net increase at night. What can be inferred about the metabolic processes occurring?
The plant is only respiring, both day and night.
The plant is only photosynthesizing, both day and night.
Photosynthesis exceeds respiration during the day, while respiration exceeds photosynthesis at night.
Respiration exceeds photosynthesis during the day, while photosynthesis exceeds respiration at night.
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
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
An organism is respiring using a substrate with the general formula . Under aerobic conditions, what would its theoretical R.Q. be?
0.5
0.7
1
1.5
During seed germination, the R.Q. is initially high but gradually declines. This shift is primarily attributed to the change in:
Ambient temperature
Availability of oxygen
Substrate being respired
Seed hydration levels
In the electron transport chain, electrons are passed from one carrier to another. What is the primary reason for this sequential transfer?
To produce water directly
To regenerate NAD+ and FAD
To release energy in a controlled manner to create a proton gradient
To directly phosphorylate ADP to ATP
How many molecules of CO2 are released per glucose molecule during the complete oxidation of glucose in aerobic respiration?
2
4
6
8
In the tricarboxylic acid cycle, which reaction involves a substrate-level phosphorylation rather than an oxidation?
Succinyl-CoA to succinate
Citrate to isocitrate
Fumarate to malate
Isocitrate to Ξ±-ketoglutarate
All of the following steps in the TCA cycle involve the reduction of or EXCEPT:
Succinyl-CoA to succinate
Isocitrate to Ξ±-ketoglutarate
Ξ±-ketoglutarate to succinyl-CoA
Malate to oxaloacetate
Which enzyme in the Krebs cycle catalyzes a reaction that directly produces a high-energy phosphate compound without involving an oxidation/reduction reaction?
Succinyl-CoA synthetase
Isocitrate dehydrogenase
Ξ±-ketoglutarate dehydrogenase
Malate dehydrogenase