Entrance Exams
Govt. Exams
Tracheids are elongated, unicellular structures with tapering end walls and pits, unlike vessels which are multicellular with perforated end plates.
The spongy mesophyll contains intercellular spaces and is located below the palisade layer, facilitating gas exchange through stomata.
C4 plants exhibit Kranz anatomy where mesophyll cells and bundle sheath cells are specialized for different aspects of photosynthesis.
The endodermis contains the Casparian strip, which regulates the movement of water and solutes into the vascular cylinder.
Companion cells are specialized parenchymatous cells that remain alive and are attached to sieve tube elements in the phloem.
Dicot stems have vascular bundles arranged in a ring or eustele pattern, whereas monocots have scattered bundles.
Xylem is a vascular tissue that transports water and minerals from roots to shoots through tracheids and vessels.
In roots, protoxylem is toward the center and metaxylem toward periphery, defining the endarch arrangement unique to roots among vascular organs.
Gymnosperm wood consists mainly of tracheids without true vessels, making it different from dicot wood which has both vessels and tracheids.
C4 plants have well-developed chloroplasts in bundle sheath cells for the Calvin cycle, while C3 plants have minimal chloroplasts in bundle sheaths.