Phloem fibers [bast fibers] are:
1. | made up of collenchyma and generally not seen in primary phloem |
2. | made up of collenchyma and generally not seen in secondary phloem |
3. | made up of sclerenchyma and generally not seen in primary phloem |
4. | made up of sclerenchyma and generally not seen in secondary phloem |
Which of the following components of the phloem tissue in angiosperms loses protoplasm and becomes dead at maturity?
1. Sieve tube elements | 2. Companion cells |
3. Phloem parenchyma | 4. Phloem fibers |
In the given diagram, the axillary bud is represented by the letter:
1. A 2. B 3. C 4. D |
Match each item in Column I with one in Column II and choose your answer from the codes given below:
Phloem components |
Feature |
A. Sieve tube elements |
a. Commercial use as in jute, flax and hemp |
B. Companion cells |
b. Plasmodesmatal connections and storage function |
C. Phloem parenchyma |
c. Maintaining pressure gradient in sieve tubes |
D. Phloem fibers |
d. Perforated end walls |
Codes
A | B | C | D | |
1. | a | b | c | d |
2. | b | a | d | c |
3. | b | d | c | a |
4. | d | c | b | a |
The meristem which occurs between mature tissues in a plant body is known as:
1. Secondary meristem | 2. Intercalary meristem |
3. Lateral meristem | 4. Cylindrical meristems |
Protophloem differs from metaphloem in having:
1. companion cells present
2. dead sieve tube elements
3. narrow sieve tubes
4. lignified phloem fibers
The incorrect statement regarding epidermal tissue system in angiosperms would be:
1. | It comprises of epidermal cells and stomata but not the appendages such as trichomes |
2. | It is the outermost layer of the primary plant body forming a continuous layer |
3. | It is usually single layered |
4. | Cells are parenchymatous with a large vacuole |
The meristem that helps grasses regenerate parts removed by the grazing herbivores is the:
1. | Shoot apical meristem | 2. | Root apical meristem |
3. | Intercalary meristem | 4. | Lateral meristem |
All the following are true for trichomes except:
1. | they are usually unicellular |
2. | they may be branched |
3. | they may be secretory |
4. | they help in prevention of water loss due to transpiration |
Permanent tissues in a plant body are formed following division of cells in:
1. Primary meristems only
2. Secondary meristems only
3. Both primary and secondary meristems
4. Neither primary nor secondary meristems