Secondary Growth in Plants

The anatomy of spring wood shows some peculiar features. Identify the correct set of statements about spring wood.

(a) It is also called the early wood.

(b) In spring, cambium produces xylem elements with narrow vessels.

(c) It is lighter.

(d) The spring wood along with autumn wood shows alternate concentric rings forming annual rings.

(e) It has a lower density.

Choose the correct answer from the options given below:

In old trees the greater part of secondary xylem is dark brown and resistant to insect attack due to:
(a) secretion of secondary metabolites and their deposition in the lumen of vessels.
(b) deposition of organic compounds like tannins and resins in the central layers of stem.
(c) deposition of suberin and aromatic substances in the outer layer of stem.
(d) deposition of tannins, gum, resin and aromatic substances in the peripheral layers of stem.
(e) presence of parenchyma cells, functionally active xylem elements and essential oils.
Choose the correct answer from the options given below:

Wood is actually a:

Vascular cambium activity is

Cambium ring forms cells towards

Periderm includes

Balloon like outgrowths inside the lumen of xylem is called

Ring like structures developed in old age tree is due to:

Heartwood differ from sapwood in:

Which of the following statement is not correct?

Read the following statements and select the correct option.

I. Vascular cambium in dicot roots is partly primary and partly secondary.

II. In dicot roots interfascicular cambia arise by dedifferentiation of cells of medullary rays.

What is the position of oldest secondary phloem?

The wood is actually a

Bark refers to all tissues exterior to the 

In a stem which is covered by periderm and in which stomata are absent, gaseous exchange takes place through:

The feature which is common to both heartwood and sapwood is 

The heartwood cannot conduct water because of 

Which of the following is the function of heartwood?

The intrafascicular cambium