In monocot stems, the vascular bundles are arranged in a pattern that is
Answer: A
Monocot stems have scattered vascular bundles distributed throughout the ground tissue, whereas dicot stems have bundles arranged in a ring.
Q.122Easy
The endodermis in roots is characterized by the presence of
Answer: A
The endodermis contains Casparian strips—bands of suberin and lignin that prevent lateral movement of water and minerals, forcing them through the cell.
Q.123Easy
Which tissue in plants is responsible for the transport of water and minerals from roots to shoots?
Answer: B
Xylem transports water and minerals (inorganic nutrients) from roots to all parts of the plant in an upward direction.
Q.124Easy
The middle lamella in plant cell walls is primarily composed of
Answer: B
The middle lamella is composed mainly of pectin and calcium pectate, which acts as a cement holding adjacent cells together.
Q.125Medium
In dicot roots, the xylem is typically arranged in a pattern described as
Answer: B
Dicot roots typically show tetrarch arrangement (4 xylem groups), while monocot roots show polyarch arrangement. Triarch is less common in roots.
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Q.126Medium
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.127Medium
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.128Medium
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.129Medium
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.130Medium
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.
Q.131Medium
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.132Medium
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.133Medium
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.134Hard
The sieve plates in sieve tube elements function to
Answer: C
Sieve plates contain pores that maintain cytoplasmic continuity between adjacent sieve tube elements, facilitating the transport of photosynthates.
Q.135Hard
In xerophytic plants, the stomata are often located in pits or grooves on the leaf surface. This adaptation is known as
Answer: A
Stomatal crypts are sunken regions containing stomata that create a microenvironment reducing transpiration by trapping moist air.
Q.136Hard
The transition from root to shoot anatomy occurs at the hypocotyl. Which vascular pattern change is observed?
Answer: B
At the hypocotyl, the root's endarch xylem (with protoxylem toward center) transitions to the shoot's exarch xylem (protoxylem toward periphery).
Q.137Hard
The bundle sheath cells in C3 plants differ from those in C4 plants by
Answer: C
C4 plants have well-developed chloroplasts in bundle sheath cells for the Calvin cycle, while C3 plants have minimal chloroplasts in bundle sheaths.
Q.138Hard
The phenomenon of secondary growth in gymnosperms differs from dicots in that gymnosperm wood lacks
Answer: A
Gymnosperm wood consists mainly of tracheids without true vessels, making it different from dicot wood which has both vessels and tracheids.
Q.139Hard
The protoxylem and metaxylem are distinguished based on their position relative to the primary xylem center. In roots, this arrangement is called
Answer: A
In roots, protoxylem is toward the center and metaxylem toward periphery, defining the endarch arrangement unique to roots among vascular organs.
Q.140Easy
Which of the following tissues is responsible for the transportation of water and minerals in plants?
Answer: A
Xylem is a vascular tissue that transports water and minerals from roots to shoots through tracheids and vessels.
