Tag: botany

In Quercus and Pinus, during secondary growth, secondary xylem show vessels without pores, also non porous vessels. It is loose and soft. So it is not considered as heart wood. So, heart wood is absent in Quercus and Pinus.

So, the correct option is ‘Quercus and Pinus’.

A.Salix  - wood is used in making boxes, brooms, cricket bats, Hockey bats,cradle boards, chairmans and other furniture, dolls, flutes, poles, sweat lodges, toys, turnery, tool handles, veneer, wands and whistles.

B.Morus – wood is used in making Fence posts, furniture, and turned objects

C.Picea – wood is used in buildings

d.Phytelephas – wood is used in making ivory.

So, the correct option is ‘ Salix’.    

In Dalbergia, during secondary growth, hart wood is formed. It consists of vessels, trachieds and parenchyma in equal proportions.

So, the correct option is ‘Vessels, trachieds, and parenchyma in equal proportions’.

In the trunk and older branches of the large trees, only the outer secondary xylem i.e. sapwood serves in water conduction. Whereas the inner part i.e. heartwood,  is composed of dead but structurally strong primary xylem. Thus the youngest layer of secondary xylem is located just inner to sapwood and not in the centre of the stem.

The correct answer is option C.

• Wood specific gravity is the measurement of the amount of dry cell-wall material per unit volume of the wood. 
• It is in such a way that probably the single most important predictor of the properties of wood. 
• It is among the species as woods range in specific gravity from less than 0.05 for Aeschynomene hispida Wild.
• Thus, the correct answer is option D.

• The hardness of a cell refers to the sturdiness of the cell wall because of the presence of lignin and cellulose present in them.
  
• Lignin is a naturally occurring complex organic cross-linked phenolic polymer that forms an important structural material of the plant cell wall (secondary cell wall).
• They are mainly found regions of wood and bark as they provide rigidity and prevents deterioration.
  
• It also provides support to tissues of vascular plants and few algae.
• So, the correct answer is 'Lignin'.

They are generally propagated by vegetative to produce offsprings which are practically clones of their parent plants. If a plant has favourable traits, it can continue to pass down its helpful genetic information to its family. This is especially economically advantageous as it allows commercial growers to clone a particular plant to ensure consistency throughout their crops.

Thus, the correct answer is C.

Cellulosic materials are comprised of lignin, hemicellulose as well as cellulose. So, these are called as lignocellulosic materials. One main function of lignin is to provide structural support for the plant. Cellulose molecules are consisting of long chains of glucose molecules. This is for that the starch molecules to have a different structural configuration. So, the preparation of pure cellulose by removing lignin is an important step in the manufacture of pulp. It is for the paper industry from the woody tissues of plants to make a better quality paper.

Removal of water from the wood by prolonged heating at approximately $50^{0} C$. The other options are not relevant.

Thus, the correct answer is option D.

Secondary xylem consists of large-sized vessels and tracheas. Their cell walls are thickened by lignin deposition and it provides excellent mechanical support to the plant. This thicken deposition is the wood of the plant and it is used for making timber.

Catch is obtained from the heartwood of Acacia species, especially from Senegalia catechu or Acacia catechu.