Prepare for NEET Biology Anatomy of Flowering Plants with MCQs & PYQs on NEET.GUIDE. Enjoy free practice, previous year questions, and expert insights on plant tissues and structures.
Which of the following is NOT a characteristic feature of collenchyma cells?
Presence of lignin in cell walls
Unevenly thickened cell walls
Living cells at maturity
Provides flexible support to the plant
The flexibility of collenchyma tissue is primarily attributed to:
The presence of lignin in the cell wall
The thin cell walls
The combination of pectin and hemicellulose in the cell wall
The intercellular spaces present between the cells
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 sclerenchyma cells primarily contributes to their exceptional strength and rigidity, making them suitable for providing structural support in plants?
Presence of lignin in the secondary cell wall
High concentration of pectin in the middle lamella
Presence of living protoplasts at maturity
Thin and flexible primary cell wall
Considering the structural adaptations of sclerenchyma, which of these statements best explains why these cells are typically dead at maturity?
The heavily lignified cell wall restricts the entry of essential substances for cellular metabolism.
Sclerenchyma cells actively undergo programmed cell death during development to enhance structural integrity.
The lack of a nucleus and other organelles reduces the metabolic burden, optimizing the cell for support.
Sclerenchyma cells are produced in excess and are shed as the plant grows, similar to epidermal cells.
Sclerenchyma provides mechanical support to plants. Which component of the cell wall contributes most to this strength?
Cellulose
Pectin
Lignin
Suberin
The lignified secondary walls of xylem elements provide:
Flexibility for bending and twisting
Storage of water and nutrients
Mechanical strength and prevention of collapse under tension
Increased surface area for water absorption
Which of the following statements is INCORRECT regarding sclerenchyma cells?
Sclerenchyma cells are living at maturity
Sclerenchyma cells have thick secondary cell walls
Sclerenchyma cells contain lignin
Sclerenchyma cells can be fibers or sclereids
The main component responsible for the rigidity of sclerenchyma cells is:
Cellulose
Pectin
Lignin
Suberin
Which of the following statements regarding the cell wall of parenchyma cells is INCORRECT?
The cell wall of parenchyma cells is primarily composed of cellulose.
The cell wall of parenchyma cells allows for flexibility and expansion.
The cell wall of parenchyma cells is connected to adjacent cells via plasmodesmata.
The cell wall of parenchyma cells is heavily lignified.
