Tag: secondary growth in stem

Questions Related to secondary growth in stem

In those plants whose pulp is of economical importance,
they are generally propagated by vegetative means because

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. It is cheaper

  2. It is more economical

  3. The pulp quality remains same

  4. The pulp quality becomes better

Show answer
Correct Option: C
Explanation:

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.

An important step in the manufacture of pulp for paper industry from the woody tissues of plants is the -

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. Removal of water form the wood by prolonged heating at approximately 50$^{\circ}$

  2. Treatment of wood with chemicals that break down cellulose

  3. Removal of oils present in the wood by treatment with suitable chemicals

  4. Preparation of pure cellulose by removing lignin

Show answer
Correct Option: D
Explanation:

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.

Timber is

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. Secondary phloem

  2. Phellem

  3. Secondary cortex

  4. Secondary xylem

Show answer
Correct Option: D
Explanation:

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.

So the correct option is D.

The commercial catch is obtained from the heart wood of

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. Acacia senegal

  2. Acacia catechu

  3. Acacia arabica

  4. All of the above

Show answer
Correct Option: B
Explanation:

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

It is used as an astringent, food additive, dye and tannin. 
So the correct option is B.

Wood with vessels of unequal diameter and with the largest vessels localized in the early wood is called.

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. Diffuse porous wood

  2. Ring porous wood

  3. Stratified wood

  4. Non-stratified wood

Show answer
Correct Option: A

Which of the following is incorrect statement?

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. Wood is actually a secondary system

  2. Different types of woods are found on the basis of their composition and time of production

  3. Monocot and dicot plant show marked

  4. Increase in girth of dicot stem by vascular cambium only

Show answer
Correct Option: A

Which of the following is incorrect statement?

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. Wood is actually a secondary xylem

  2. Different types of woods are found on the basis of their composition and time of production

  3. Monocot and dicot plant show marked variation in their internal structure

  4. Increase in girth of dicot stem by vascular cambium only

Show answer
Correct Option: A

Select the correct option:

Increase in girth of the plant as a result of the activities of primary and secondary lateral meristems is called

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. primary growth

  2. lateral growth

  3. secondary growth

  4. intercalary growth

Show answer
Correct Option: C
Explanation:

Secondary growth is characterized by an increase in thickness or girth of the plant, and is caused by cell division in the lateral meristem, which are lacking in herbaceous plants. Lateral meristems include the vascular cambium and, in woody plants, the cork cambium.

So, the correct option is 'Secondary growth'.

Which of the following statements are correct about heartwood?

(i) It does not help in water conduction.
(ii) It is also called alburnum.
(iii) It is light in colour and is very soft.
(iv) It has tracheary elements which are filled with tannins, resins, etc.
botany plants in daily life types of wood importance of plants secondary growth in stem

  1. (ii) and (iv)

  2. (i), (ii) and (iii)

  3. (ii), (iii) and (iv)

  4. (i) and (iv)

Show answer
Correct Option: D
Explanation:

Heartwood is non -functional as it does not conduct water and minerals. It may have ingrowths of tylosis, deposition of resins, tannins and other secondary metabolites of the plant. It is hard and is also called duramen.

So, the correct answer is '(i) and (iv)'

Select the correct option:

In (i) porous wood, vessels are very broad in the (ii) wood and are quite narrow in the (iii) wood. This kind of wood is present in (iv) and it translocates (v) amount of water when required by the plant.
Select the correct fill ups for the above paragraph.

botany plants in daily life types of wood importance of plants secondary growth in stem

  1. (i)-diffuse, (ii)-autumn, (iii)-spring, (iv)-Dalbergiasissoo, (v)-more

  2. (i)-diffuse, (ii)-spring, (iii)-autumn, (iv)-Syzygiumcumini, (v)-less

  3. (i)-ring, (ii)-spring, (iii)-autumn, (iv)-Dalbergiasissoo, (v)-more

  4. (i)-ring, (ii)-autumn, (iii)-spring, (iv)-Syzygiumcumini, (v)-less

Show answer
Correct Option: C
Explanation:
Due to the presence of vessels, the wood is said to be porous. Vessels present in the spring or earlywood are very large and form conspicuous rings in this wood while those present in the autumn wood or latewood are small or only moderately large. The wood with these characteristics is called ring porous.
This kind of wood present in Dalbergia sissoo( Papilionoideae). It translocates more amount of water when required by the plant.
So, the correct answer is '(i) ring, (ii)- spring, (iii)- autumn, (iv)- Dalbergiasissoo, (v)- more'.