28
Arrange the following in the sequence you would find them in a plant starting from the periphery-phellem, phellogen, phelloderm.
Explanation
Phellem or cork is the outer most layer, followed by phellogen (cork cambium) which in turn is followed by phelloderm (secondary cortex).
29
If one debarks a tree, what parts of the plant is being removed?
Explanation
Debark means the removal of bark, i.e., all tissue exterior to the vascular cambium, including secondary phloem. Bark refers to a number of tissue types, viz., periderm (phellogen, phellem and phelloderm) and secondary phloem.
30
The cross-section of a plant material showed the following features when viewed under the microscope.
(a) The vascular bundles were radially arranged.
(b) Four xylem strands with exarch condition of protoxylem. To which organ should it be assigned?
Explanation
Root is the organ which shows the features given in the question. Vascular bundles are present on separate radii thus called radial arrangement. Protoxylem is towards periphery of root thus making exarch condition.
31
What do hardwood and softwood stand for?
Explanation
Distinguish between softwood and hardwood is as
| Softwood | Hardwood |
|---|---|
| Gymnospermic wood is soft wood It chiefly contains trachieds Vessels are absent. |
Angiospermic wood is hard wood It chiefly contain both trachieds and vessels Trachieds are absent. |
32
While eating peach or pear it is usually seen that some stone like structures get entangled in the teeth, what are these stone like structures called?
Explanation
The pulpy part of fruit of peach and pear, the stone cells are present, which are an sclerenchymatous cells and which are dead in nature. Their function is to give mechanical support to the soft tissue.
