Advertisements
Advertisements
प्रश्न
A timber merchant bought 2 logs of wood from, a forest & named them A & B, The log A was 50 year old & B was 20 years old. Which log of wood will last longer for the merchant? Why?
उत्तर
- In wood, the older it is, the stronger it becomes.
- Log A - Which was 50 years old is stronger and it will last longer.
- In a tree the central part of the wood will be darker in colour, dead in nature known as Heartwood or Duramen, and the outer sad wood is lighter in colour, living and conducting water.
- In the central Heartwood the conduction is blocked by the formation of tyloses from the nearby parenchyma cells, and dead.
- In the fully developed tyloses, starch crystals, resins, gums, oils tannins and coloured substances are found and it becomes very hard and durable.
- It is more resistant to the attack of microbes and insects like termites.
- Older woods have more heartwood than sapwood.
- Here log ‘A’ is older, has more heartwood and it is stronger and will last longer.
संबंधित प्रश्न
Consider the following statements.
In spring season vascular cambium:
- is less active
- produces a large number of xylary elements
- forms vessels with wide cavities of these.
Usually, the monocotyledons do not increase their girth, because ______.
In the diagram of lenticel identify the parts marked as A, B, C, D.
The common bottle cork is a product of ______.
In a forest, if the bark of a tree is damaged by the horn of a deer, How will the plant overcome the damage?
In which season the vessels of angiosperms are larger in size, why?
Continuous state of dividing tissue is called meristem. In connection to this, what is the role of lateral meristem?
A transverse section of the trunk of a tree shows concentric rings which are known as growth rings. How are these rings formed? What are the significance of these rings?
Inner, darker & harder portion of secondary xylem that cannot conduct water in an older dicot stem is called ____________.
