Which anatomical feature in desert plants allows them to store water in their stem tissues?
Answer: C
Succulent plants like cacti have specialized thin-walled parenchymatous tissues that store water. The waxy cuticle reduces water loss, not parenchyma.
Q.62Medium
The palisade parenchyma in leaves is primarily adapted for
Answer: B
Palisade parenchyma consists of elongated cells arranged perpendicular to the leaf surface, maximizing light capture for photosynthesis.
Q.63Medium
In older dicot stems, the cork cambium (phellogen) originates from which tissue?
Answer: B
The phellogen typically develops from cortical or endodermal cells in dicot stems, occasionally from the epidermis, replacing the original epidermis.
Q.64Medium
The bulliform cells found in monocot leaves are primarily involved in
Answer: C
Bulliform cells are large, vacuolated cells on the adaxial surface of monocot leaves that control leaf rolling to reduce water loss during drought.
Q.65Medium
Which of the following is a characteristic feature of collenchyma tissue?
Answer: B
Collenchyma has unequally thickened primary cell walls, usually at corners, providing mechanical support while remaining flexible. It retains living protoplasm.
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Q.66Medium
The phenomenon where secondary xylem appears as annual rings in cross-sections of dicot stems is due to
Answer: A
Annual rings form due to seasonal variations in xylem formation: large earlywood cells (spring) and smaller latewood cells (summer), creating visible rings.
Q.67Medium
In hydrophytes, which structural modification reduces the density of tissues to maintain buoyancy?
Answer: B
Aerenchyma—parenchymatous tissue with large intercellular air spaces—provides buoyancy and oxygen transport in aquatic plants.
Q.68Medium
The periderm in woody plants consists of three layers. Which layer actively produces new cells?
Answer: B
The cork cambium (phellogen) is the meristematic layer that divides to produce cork cells outwardly and phelloderm inwardly.
Q.69Medium
The endodermis in a root is primarily involved in:
Answer: B
The endodermis contains the Casparian strip, which regulates the movement of water and solutes into the vascular cylinder.
Q.70Medium
Which anatomical feature is characteristic of C4 plants?
Answer: A
C4 plants exhibit Kranz anatomy where mesophyll cells and bundle sheath cells are specialized for different aspects of photosynthesis.
Q.71Medium
Tracheids differ from vessels in that tracheids:
Answer: B
Tracheids are elongated, unicellular structures with tapering end walls and pits, unlike vessels which are multicellular with perforated end plates.
Q.72Medium
The Casparian strip is impregnated with which substance?
Answer: B
The Casparian strip in endodermis is impregnated with suberin, making it impermeable to water and solutes, thus forcing them through the endodermal cells.
Q.73Medium
Which of the following represents the correct sequence of tissue layers from outside to inside in a dicot stem?
Answer: C
In a young dicot stem, the sequence from outside is: cuticle, epidermis, cortex (containing hypodermis and endodermis), vascular bundles, and central pith.
Q.74Medium
In monocot roots, the pericycle is typically:
Answer: A
In monocot roots, the pericycle is usually uniseriate and gives rise to lateral roots, unlike in dicots where it's multiseriate.
Q.75Medium
Which adaptation in desert plants helps reduce water loss through leaves?
Answer: B
Desert plants (xerophytes) have smaller leaves, thicker cuticles, and often sunken stomata to minimize water loss through transpiration.
Q.76Medium
In aquatic plants, the aerenchyma tissue functions primarily to:
Answer: B
Aerenchyma is specialized parenchyma with large air spaces that provides buoyancy and allows diffusion of gases in hydrophytes.
Q.77Medium
The cork cambium (phellogen) originates from:
Answer: C
The cork cambium originates from the endodermis or outer cortical cells and produces cork and phelloderm as part of the periderm.
Q.78Medium
The xylem in angiosperms is primarily composed of:
Answer: C
Angiosperm xylem consists of vessels (main conducting element), tracheids, xylem parenchyma (storage), and xylem fibers (support).
Q.79Medium
Which anatomical adaptation is specific to insectivorous plants like pitcher plants?
Answer: B
Insectivorous plants have anatomically modified leaves (pitchers, traps) with specialized glandular and digestive tissues to trap and digest insects.
Q.80Medium
The Casparian strip found in the endodermis of roots is composed primarily of:
Answer: A
The Casparian strip is an impermeable band of suberin and lignin that prevents lateral movement of water and minerals, forcing them through the endoderm symplastically.
