Monocot stems do not have
1. Protophloem
2. Phloem parenchyma
3. Companion cell in phloem
4. Sieve tube and metaphloem
Choose the correct option with respect to sclereids
1. Physiologically active
2. Pits are present
3. Derived from meristems directly
4. Little amount of protoplasm is present
Collenchyma is characterised by
1. Absence of protoplast at maturity
2. Supporting young stem and leaf petiole
3. Lignocellulosic thickening on secondary walls
4. The common presence of intracellular spaces
Epidermal hairs on stems known as trichomes
1. May sometimes be secretory in function
2. Have vascular supply
3. May be soft or stiff but unbranched always
4. Are endogenous in origin like lateral roots
Select the incorrect statement with respect to bast fibres
a. Generally absent in primary phloem
b. Elongated, branched with blunt ends
c. Parenchymatous in nature
d. Becomes dead at maturity
1. a & d
2. b & d
3. b & c
4. a & b
Sieve tube elements are long, tube-like structures, arranged longitudinally and associated with the companion cells. A mature sieve element
1. Has a small vacuole
2. Lacks nucleus and cytoplasm
3. Possesses a large vacuole and small nucleus
4. Possesses a peripheral cytoplasm
During the secondary growth in the dicot stem, the cambial ring becomes active and begins to cut off new cells both towards the inner and the outer sides. The cells cut off
1. Towards pith, mature into secondary phloem
2. Towards the periphery, mature into secondary xylem
3. Towards pericycle, mature into secondary xylem as well as secondary phloem
4. Mature into secondary vascular tissues
Match the column I with column II
Column I | Column II | ||
a. | Xylem parenchyma | (i) | Absent in most of the monocots |
b. | Sclereids | (ii) | Lond cylindrical tube-like structure |
c. | Phloem parenchyma | (iii) | Food and tannins |
d. | Vessel | (iv) | Fruit walls of nuts |
1. a(i), b(ii), c(iii), d(iv)
2. a(ii), b(iv), c(iii), d(i)
3. a(iii), b(iv), c(i), d(ii)
4. a(iii), b(ii), c(i), d(iv)
Select the odd one out with respect to tissues
1. A group of cells having a common origin
2. They usually perform a common function
3. Complex tissues are made of more than one type of cells
4. They are not capable of division
Which of the following component of phloem is mainly responsible for the storage of food material and other substances like resins, latex and mucilage?
1. Sieve tube
2. Companion cell
3. Bast fibres
4. Phloem parenchyma