Prepare for NEET with Botany-specific practice questions. Covering all major Botany chapters, this is perfect for your NEET Biology needs.
A dry wooden block and a dry gelatine block of equal mass are placed in water. The gelatine block imbibes considerably more water than the wooden block. This difference is primarily attributed to:
The higher density of wood compared to gelatine.
The greater number of hydrophilic colloids in gelatine compared to wood.
The presence of lignin in wood, which repels water.
The lower osmotic potential of gelatine compared to wood.
Seeds of certain desert plants exhibit delayed germination due to the presence of inhibitors. How does imbibition contribute to overcoming this dormancy?
Imbibition increases the seed's internal temperature, denaturing the inhibitors.
Imbibition activates enzymes within the seed that break down the inhibitors.
Imbibition allows water to enter the seed and leach out the inhibitors, promoting germination.
Imbibition increases the seed's turgor pressure, rupturing the seed coat and releasing the inhibitors.
If dry wooden blocks are placed in a solution with a solute potential of -0.5 MPa, and the initial water potential of the wood is -2.0 MPa, which of the following will occur?
Water will move from the solution into the wooden blocks.
Water will move from the wooden blocks into the solution.
No net movement of water will occur.
The wooden blocks will dissolve in the solution.
Which of the following scenarios would result in the LEAST efficient water absorption by a plant's roots?
Slightly acidic soil with optimal nutrient availability
Well-aerated soil with moderate water content
Low soil temperature coupled with high humidity
High soil salinity coupled with low soil oxygen levels
A plant with a mutation that disables aquaporins in its root cells would likely exhibit:
Complete cessation of water uptake.
Enhanced water uptake due to increased reliance on the apoplast pathway.
Reduced rate of water uptake but not complete cessation.
No change in water uptake as aquaporins are primarily involved in transpiration.
A researcher is studying long-distance transport in a plant. They introduce a radioactive tracer into the phloem sap of a source leaf. Which of the following would LEAST likely be observed after a period of time?
Movement of the tracer towards a developing fruit
Presence of the tracer in the root tips
Detection of the tracer in a sink leaf
Significant accumulation of the tracer in mature xylem vessels of the source leaf
Which of the following manipulations would MOST directly inhibit the loading of sucrose into the sieve tube elements at the source?
Decreasing the hydrostatic pressure in the sieve tube elements
Blocking plasmodesmata between companion cells and sieve tube elements
Increasing the concentration of sucrose in the sink
Inhibition of apoplastic proton pumps in companion cells
Girdling experiments, where the bark of a tree is removed in a ring around the trunk, demonstrate the importance of phloem for translocation. Which observation is NOT expected after girdling?
Accumulation of sugars above the girdle.
Swelling of the bark above the girdle.
Eventual death of the roots due to lack of nutrients.
Increased sugar concentration above the girdle and decreased sugar concentration below the girdle, with no effect on xylem function.
A xerophyte with a CAM pathway faces prolonged drought conditions. Which of the following physiological responses would be LEAST likely to occur?
Increased stomatal aperture during the day
Accumulation of organic acids at night
Reduced transpiration rates
Increased root-to-shoot ratio
The cohesion-tension theory explains the ascent of sap in tall trees. Which of the following factors LEAST contributes to the maintenance of the continuous water column?
Active transport of water into xylem vessels
Cohesion between water molecules
Adhesion of water molecules to xylem walls
Transpiration pull generated by evaporation from leaves
