Read the different components from I to IV in the list given below and tell the correct order of the components with reference to their arrangement from the outer side to the inner side in a woody dicot stem.
I. | Secondary Cortex |
II. | Wood |
III. | Secondary phloem |
IV. | Phellem |
The correct order is:
1. | III, IV, II, I | 2. | I, II, IV, III |
3. | IV, I, III, II | 4. | IV, III, I, II |
Tracheids differ from the tracheary elements in:
1. Having casparian strips
2. Being imperforate
3. Lacking nucleus
4. Being lignified
Gymnosperms are also called softwood spermatophytes because they lack:
1. Cambium
2. Phloem fibres
3. Thick-walled tracheids
4. Xylem fibres
1. all tissues except epidermis and vascular bundles
2. epidermis and cortex
3. all tissues internal to endodermis
4. all tissues external to endodermis
The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is:
1. maturing
2. elongating
3. widening
4. differentiating
1. shoot apical meristem
2. position of axillary buds
3. size of leaf lamina at the node below each internode
4. intercalary meristem
Tyloses an outgrowth from ray or axial parenchyma cell into the lumen of a vessel, which partially or completely blocks the cavity, are present in:
1. Periderm
2. Heartwood
3. Sapwood
4. Secondary cortex
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