The Question is from neet-botany plant-physiology long-distance-transport, and it was created by the author B VENKAT

Question

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?

B VENKAT · Accepted Answer

## CORE INFORMATION
✓ **Answer**: 4
## CONCEPT FRAMEWORK
 **Primary Concept**: Plant Translocation and the role of Phloem
 **Related Topics**: Plant Anatomy, Photosynthesis, Respiration, Plant Transport Systems
 **Prerequisites**: Understanding of phloem's function in transporting sugars and other organic compounds, and xylem's function in transporting water and minerals.
## SOLUTION PATHWAY
**Given Information**:
  Girdling experiment: Removal of a ring of bark (containing phloem) around the tree trunk.
  Phloem's role: Translocation of sugars from leaves to other parts of the plant.
**Method & Steps**:
 1. Understand the role of phloem in translocation.
  Reasoning: Phloem transports sugars produced during photosynthesis from the leaves to other parts of the plant, including the roots.
 2. Analyze the effect of girdling on phloem transport.
  Working: Removing the phloem disrupts this transport. Sugars accumulate above the girdle because they cannot be transported downwards.
  Key Point:  Xylem transport (water and minerals) is not directly affected by girdling.
 3. Determine the unexpected observation.
  Result: Option 4 states 'Increased sugar concentration above the girdle and decreased sugar concentration below the girdle, with no effect on xylem function.' This is expected.  The other options are all expected consequences of girdling.
  Verification: The other options (accumulation of sugars above, swelling above, root death due to lack of nutrients) are all direct consequences of disrupting phloem transport.
 ## OPTION ANALYSIS
A ✓: Accumulation of sugars above the girdle. This is expected because the downward transport of sugars is blocked.
B :x: Swelling of the bark above the girdle.  This is expected due to the accumulation of sugars and water above the girdle.
C :x: Eventual death of the roots due to lack of nutrients. This is expected because the roots are deprived of sugars and other organic compounds transported by the phloem.
D :x: Increased sugar concentration above the girdle and decreased sugar concentration below the girdle, with no effect on xylem function. This is the expected outcome; it accurately reflects the effects of girdling.
 ## LEARNING AIDS
 **Common Mistakes**:
  1.Confusing the roles of xylem and phloem: Remembering that xylem transports water and minerals while phloem transports sugars and other organic compounds is crucial.
  2.Misinterpreting the effect of girdling: Girdling only affects phloem transport; xylem transport remains unaffected.
 **Quick Tips**:
  1.Visualize the process: Imagine the flow of sugars being blocked by the removal of the phloem.
  2.Mnemonic:  'Xylem up, Phloem down' (though phloem transports in both directions) to remember the general direction of transport.

B VENKAT · Answer

Accumulation of sugars above the girdle.

B VENKAT · Answer

Swelling of the bark above the girdle.

B VENKAT · Answer

Eventual death of the roots due to lack of nutrients.

B VENKAT · Answer

The correct Option is "Increased sugar concentration above the girdle and decreased sugar concentration below the girdle, with no effect on xylem function."

NEET Botany Transport in Plants Long Distance Transport MCQs

Select Topic

Question Tags

Question Tags

NEET Subjects

Our Bots

Company