Prepare for NEET Biology Photosynthesis in Higher Plants (Photorespiration And C4-Cycle) with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert solutions to understand pathways reducing photorespiratory losses.
NEET Questions / Botany / Photosynthesis in Higher Plants / Photorespiration And C4-Cycle
A researcher is studying a C4 plant under controlled conditions. They suddenly increase the oxygen concentration in the environment while maintaining constant light and CO2 levels. Which of the following is the MOST likely immediate consequence?
A significant decrease in the rate of photosynthesis
A slight increase in photorespiration
A significant increase in the rate of photosynthesis
No change in the rate of photosynthesis or photorespiration
In a hypothetical experiment, a scientist genetically modifies a C4 plant to lack PEP carboxylase. Which of the following would be the MOST likely outcome under normal atmospheric conditions?
The plant would switch to CAM photosynthesis.
The plant would exhibit significantly reduced CO2 fixation and increased photorespiration.
CO2 fixation would remain unchanged, but the plant would require more water.
The plant would grow more efficiently due to reduced energy expenditure in the C4 pathway.
The ratio of oxygen consumed to CO2 released during photorespiration is:
1:1
1:2
2:1
3:1
Which of the following metabolites is transported from mesophyll cells to bundle sheath cells in C4 plants during active photosynthesis?
3-Phosphoglycerate (3-PGA)
Glyceraldehyde 3-phosphate (G3P)
Pyruvate
Malate or aspartate
A plant is exposed to an environment with high CO2 and low O2 concentrations. Which process would be MOST directly and significantly inhibited under these conditions?
Calvin cycle
Photorespiration
Electron transport chain
C4 cycle
Under conditions of high temperature and light intensity, why do C4 plants show higher photosynthetic rates compared to C3 plants?
C4 plants have a higher affinity for CO2 than C3 plants.
C4 plants open their stomata more frequently than C3 plants.
C4 plants can utilize a wider range of light wavelengths compared to C3 plants.
Spatial separation of initial CO2 fixation and the Calvin cycle minimizes photorespiration.
In C4 plants, the initial carboxylation reaction occurs in:
Mesophyll cells
Bundle sheath cells
Both mesophyll and bundle sheath cells
Neither mesophyll nor bundle sheath cells
Photorespiration is initiated by the enzyme RuBisCO's ability to also bind:
O2
CO2
N2
H2O
Which of the following is NOT a characteristic of C4 plants?
High CO2 compensation point
Kranz anatomy
Presence of PEP carboxylase
Dimorphic chloroplasts
The primary benefit of the C4 pathway is:
Minimizing photorespiration
Increasing water use efficiency
Enhancing light absorption
Reducing the need for RuBisCO
