The term 'bark' refers to:
1. | phellem, phelloderm and vascular cambium |
2. | periderm and secondary xylem |
3. | cork cambium and cork |
4. | phellogen, phellem, phelloderm and secondary phloem |
In the sieve elements, which one of the following is the most likely function of P-proteins?
1. Depletion of callose on sieve plates
2. Providing energy for active translocation
3. Autolytic enzymes
4. Sealing off mechanism on wounding
1. Stomata
2. Hydathode
3. Guard cell
4. None of these
1. Epidermal extensions
2. Hypodermis
3. Endodermis
4. Epidermal appendages
1. Cucurbita
2. Salvia
3. Calotropis
4. None of these
1. Ventral meristem
2. secondary meristem
3. Primary meristem
4. All of these
1. Salvia
2. Helianthus
3. Althaea
4. Cucurbita
1. bast fibers
2. sieve tubes
3. companion cells
4. sieve cells
Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following :
1. Tyloses in vessels
2. Closure of stomata
3. Flaccidity of bulliform cells
4. Shrinkage of air spaces in spongy mesophyll
Phloem in gymnosperms lacks:
1. Both sieve tubes and companion cells
2. Albuminous cells and sieve cells
3. Sieve tubes only
4. Companion cells only