1. Which of the following factors promotes the opening of the stomatal aperture?
(a) A decrease in guard cell turgidity
(b) When the outer walls of the guard cells contracts
(c) Radial orientation of the cellulose microfibrils in the cell wall of the guard cells
(d) The longitudinal orientation of the cellulose microfibrils in the cell wall of guard cells
Answer: :: (c)
2. Which of the following is made of dead cells?
(a) Phloem
(b) Phellem
(c) Collenchyma
(d) Xylem parenchyma
Answer: :: (b)
3. Which of the following statement are true about the Tyloses – the balloon-shaped structures?
(a) Characterise the sapwood
(b) Original in the lumen of vessels
(c) Are linked to the ascent sap through xylem vessels
(d) Are extensions of the xylem parenchyma cells into vessels
Answer: :: (d)
4. Which of the following events takes place in a ring girdled plant?
(a) The eath of the root first
(b) The death of the shoot first
(a) The shoots and the root dies first
(d) Neither the shoot nor the root will die
Answer: :: (c)
5. This is one of the most recent and valid explanations for stomatal movements.
(a) Starch hydrolysis
(b) Transpiration
(c) Guard cell photosynthesis
(d) Potassium efflux and the influx
Answer: :: (d)
6. Which of the following are the primary water-conducting elements of xylem in gymnosperms?
(a) Fibres
(b) Vessels
(c) Tracheids
(d) Transfusion tissue
Answer: :: (c)
7. Which of the following is not a lateral meristem?
(a) Phellogen
(b) Cork cambium
(c) Intercalary meristem
(d) Interfascicular cambium
Answer: :: (c)
8. In monocots, grafting is not possible as _________
(a) They show parallel venation
(b) they have scattered vascular bundles
(c) they lack cambium
(d) they are herbaceous
Answer: :: (c)
9. Vascular bundles are closed in monocots as:
(a) presence of vascular cambium between xylem and phloem
(b) presence of xylem and phloem
(c) absence of vascular cambium
(d) xylem and phloem occur in separate bundles
Answer: :: (c)
10. Difference between heartwood and sapwood is that heartwood
(a) shows the presence of fibres and rays
(b) has dead and non-conducting elements
(c) lacks parenchyma and vessels
(d) is susceptible to pathogens and pests
Answer: :: (b)