16533.In guard cells, when sugar is converted into starch, what takes place to the stomatal pore?
It closes completely.
It opens fully.
It opens partially
It remains unchanged
16535.Dixon and Joly are associated with
Light reaction and photosynthesis
Anaerobic respiration
Cohesion theory of ascent of sap
Apical dominance
16537.In a cell ruptures, on placing in a solution, the solution is said to be _____ with respect to cell sap
hypotonic
isotonic
hypertonic
pure water
16538.The most widely accepted theory for ascent of sap in trees is
Capillarity
Role of atmospheric pressure
Pulsating action of living cell
Transpiration pull and cohesion theory of Dixon and Joly
16539.Root pressure helps in ascent of sap by
pumping food in phloem
pumping sap into xylem in roots
pumping sap in stem for sending it to roots
all of the above
16540.In an angiosperm main conduction of water occurs through ________.
tracheids
sieve tubes
vessels
companion cells
16541.Maximum root pressure is observed when
Transpiration and absorption are very low
Transpiration and absorption are very high
Transpiration is high and absorption is low
Transpiration is low an dabsorption is high
16542.Guard cells differ from epidermal cells in having
Mitochondria
Vacuoles
Cell Wall
Chloroplasts