. The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is (CBSE -AIPMT ) a. maturing b. elongating c.
widening d. differentiating . Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by the (CBSE- AIPMT ) a. absence of secondary xylem b.
absence of secondary phloem c. presence of cortex d. position of protoxylem . In barley stem, vascular bundles are (CBSE -AIPMT ) a.
open and scattered b. closed and scattered c. open and in a ring d. closed and radial .
Palisade parenchyma is absent in the leaves of (CBSE- AIPMT ) a. sorghum b. mustard c. soyabean d.
gram . Wound healing is due to (JIPMER ) a. ventral meristem b. secondary meristem c.
primary meristem d. all of these . Which of the following tissues consists of living cells (JIPMER ) a. vessels b.
tracheids c. companion cell d. sclerenchyma . The Quiescent centre in root meristem serves as a (JIPMER ) a.
site for storage of food, which is utilized during maturation b. reservoir of growth hormones c. reserve for replenishment of damaged cells of the meristem d. region for absorption of water .
In the sieve elements, which one of the following is the most likely function of P.Proteins? (JIPMER ) a) Deposition of callose on sieve plates b. Providing energy for active translocation c. Autolytic enzymes d.
Sealing-off mechanism on wounding .Which of the following is made up of dead cells? (NEET ) a. Xylem parenchyma b. Collenchyma c.
Phellem d. Phloem . The vascular cambium normally gives rise to (NEET ) a. phelloderm b.primary phloem c.
secondary xylem d. periderm . Which of the following plants shows multiple epidermis? (Manipal ) a.
Croton b. Allium c. Nerium d. Cucurbita Unit - Plant Physiology .
The water potential of pure water is (NEET ) a. Less than zero b. More than zero but less than one c. More than one d.
Zero . Transpiration and root pressure cause water to rise in plants by (NEET