Prepare for NEET with Botany-specific practice questions. Covering all major Botany chapters, this is perfect for your NEET Biology needs.
A researcher applies a potent respiratory inhibitor to the root cells of a plant. Which of the following would be MOST directly affected, ultimately impacting root pressure?
Water potential gradient between the soil and root hairs
Cohesion and adhesion of water molecules in the xylem
Transpiration pull from the leaves
Active transport of ions into the xylem
Under which of the following specific environmental conditions would guttation be LEAST likely to occur?
Cool, humid night with high soil moisture
Warm, humid morning with adequate soil moisture
Cool, dry night with moderate soil moisture
Hot, dry day with low soil moisture
If the water potential of root cells is -0.5 MPa and the water potential of the xylem sap is -0.7 MPa, which statement BEST describes the movement of water?
Water will move from the xylem into the root cells
Water will move from the root cells into the xylem
There will be no net movement of water
Water will move equally in both directions
A plant exhibits vigorous guttation during the night. Which of the following would be the MOST likely consequence of completely sealing the hydathodes with a waterproof sealant without harming the plant otherwise?
A significant decrease in root pressure
A substantial increase in transpiration rate
No change in root pressure or transpiration rate
A slight increase in root pressure
The transport of glucose into most animal cells occurs via:
Simple diffusion
Facilitated diffusion using channel proteins
Facilitated diffusion using carrier proteins
Active transport
A plant cell placed in a hypotonic solution will:
Become plasmolysed
Become flaccid
Become turgid
Remain unchanged
If the mass flow hypothesis were entirely accurate, which scenario would be LEAST likely to occur in a plant?
Movement of sucrose from a leaf to a developing fruit.
Higher turgor pressure in phloem sieve tubes near a photosynthesizing leaf compared to those near a root tip.
Simultaneous bidirectional transport of different organic molecules within the same sieve tube element.
Changes in phloem sap composition based on the source and sink tissues involved.
Researchers manipulate a plant's phloem by selectively blocking plasmodesmata connecting companion cells to sieve tube elements near a leaf. Which outcome would provide the STRONGEST evidence AGAINST the mass flow hypothesis?
Accumulation of sucrose in the leaf and reduced transport to the roots.
Increased turgor pressure in the sieve tubes near the leaf.
Uninterrupted flow of sucrose from the leaf to the roots.
Decreased water potential in the sieve tubes near the leaf.
Imagine a hypothetical plant where sucrose transporters in companion cells are genetically modified to actively transport sucrose out of sieve tubes near the source. Assuming all other aspects of phloem structure and function remain the same, what would be the MOST likely effect on translocation according to the mass flow hypothesis?
Translocation would proceed normally, as the pressure gradient is independent of companion cell activity.
Translocation would be enhanced, as sucrose would be actively removed from the sieve tubes, creating a stronger sink.
Translocation would be significantly reduced or stopped, as the pressure gradient would be reversed or eliminated.
The direction of translocation would be reversed, with flow occurring from sink to source.
Which of the following processes is primarily driven by diffusion?
Active transport of ions across a cell membrane
Bulk flow of water in xylem
Gas exchange in alveoli
Muscle contraction
