A pressure created by active secretion of salts and other solutes from other cells into xylem sap is called___________?

A. Transpiration pull
B. Root pressure
C. Osmotic pressure.
D. None of these

Stomatal transpiration is __________ of total transpiration

A. 90%
B. 91%
C. 93%
D. 95%

___________ function as multisensory hydraulic valve?

A. Lenticels
B. Guard cells
C. Hydathods
D. All of these

_________ give rise to macrophages, which destroy larger particles by phagocytosis.

A. Nautrophils
B. Basophila
C. Monocyte
D. Lymphocyte

Which of the following are proteins in nature?

A. Antibodies.
B. Interferons
C. Antitoxins
D. All of these

Aerating openings formed in the bark through which exchange of gases takes place and water is lost in the form of vapours are___________?

A. Hydathods
B. Stomata
C. Lenticels
D. None of these

Lenticels look like__________?

A. A big pore
B. Stoma
C. Sponge
D. Cars or small protusions

Transport of minerals from soil to epidermal cells of roots via carrier protein molcules along their concentration gradient is called___________?

A. Diffusion.
B. Facilitated diffusion.
C. Passive transport.
D. Active transport.

Pulling upward of water and dissolved minerals towards the leaves through the xylem tissue is called__________?

A. Transpiration pull
B. Root pressure
C. Ascent of sap.
D. All of these

Which of the following have thickest walls?

A. Arteries
B. Veins
C. Capillaries
D. None of these