Prepare for NEET Biology Anatomy of Flowering Plants (Xylem) with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert insights to understand water-conducting elements: tracheids, vessels, fibers.
NEET Questions / Botany / Anatomy of Flowering Plants / Xylem
A researcher is studying the transport of water in a genetically modified plant where the lignin biosynthesis pathway is disrupted. Which of the following is the MOST likely consequence observed in the xylem of this plant?
Increased tensile strength of xylem vessels and enhanced water transport
Collapsed xylem vessels and reduced water transport efficiency
No significant change in xylem structure or water transport
Increased flexibility of xylem vessels and improved water transport under stress
Which specific characteristic of bordered pits in xylem tracheids facilitates the unidirectional flow of water while also preventing the spread of air embolisms?
Thickened secondary cell walls surrounding the pits
Presence of a torus and a flexible pit membrane
Overlapping arrangement of tracheids
Presence of tyloses within the tracheids
In a plant experiencing severe drought, which adaptation related to xylem anatomy would MOST effectively minimize the risk of cavitation?
Wider xylem vessels for increased water storage
Thinner xylem walls for increased flexibility
Narrower xylem vessels with thicker walls
Increased number of bordered pits for inter-vessel water transfer
The protoxylem and metaxylem in a plant stem differ primarily in:
Their cellular composition (tracheids vs. vessel elements)
The timing of their differentiation and the extent of secondary wall thickening
Their location within the vascular bundle
Their function in water transport versus nutrient transport
Which of the following BEST explains why the ascent of sap in tall trees is primarily attributed to the cohesion-tension theory rather than root pressure?
Root pressure only operates during the night
Root pressure is primarily involved in nutrient transport, not water transport
Root pressure alone cannot generate sufficient pressure to overcome the gravitational force in tall trees
The cohesion-tension theory is more energy-efficient than root pressure
How does the arrangement of cellulose microfibrils in the secondary cell walls of xylem vessels contribute to their function?
Facilitates rapid water flow through the vessel lumen
Increases the flexibility of the vessel walls
Provides strength and prevents collapse under negative pressure
Regulates the passage of ions and nutrients into the xylem sap
Given below are two statements:
Statement I: Endarch and exarch are terms used to describe the position of protoxylem in the plant body.
Statement II: Exarch condition is the most common feature of the root system.
In the light of the above statements, choose the correct answer from the options given below:
Both Statement I and Statement II are correct
Both Statement I and Statement II are incorrect
Statement I is correct but Statement II is incorrect
Statement I is incorrect but Statement II is correct
Which of the following correctly describes the xylem arrangement in a dicot root?
Endarch
Exarch
Mesarch
Centerarch
In a typical monocot stem, the xylem arrangement is:
Endarch
Exarch
Mesarch
Centerarch
If the protoxylem is located towards the center of the vascular bundle, the arrangement is termed:
Endarch
Exarch
Centrifugal
Centripetal
