Much of the transpiration takes place through ___________.
stomata
lenticels
cuticle
epidermis
The ascent of sap in plants takes place due to __________.
root pressure
transpiration pull
both a and b
osmosis
Stomata open and close due to _____________.
presence of valves
hormonal control
turgor pressure of guard cells
concentration gradient of the gases
The colour of blood in the arteries is _________
bright red
dark red
blue
black
Transpiration takes place from ________________.
all parts of the plant
roots
only the aerial parts
stem
__________ carries oxygenated blood.
pulmonary artery
hepatic portal vein
pulmonary vein
all of the above
Blood is composed of ___________.
plasma and red blood cells
plasma and formed elements
red and white blood cells
red blood cells, white blood cells and platelets
Thick muscular walls are present in ___________.
arteries
arterioles
veins
venules
The roots absorb water through _______________.
epidermal hairs
root hairs
root xylem
root phloem
Stomata are present on the __________ of the leaves.
upper surface only
lower surface only
mostly upper surface
mostly lower surface
