In which of the following is secondary growth typically observed?

Distinguish between the following: Interfascicular cambium and intrafascicular cambium.

Select the correct statement$(s)$:
$(1)$ Lenticels are absent in woody climbers.
$(2)$ Lenticels are found in most woody trees.
$(3)$ Spring wood is lighter in color and has a lower density.
$(4)$ Sapwood is also known as duramen (heartwood).

Which of the following meristems is responsible for extrastelar secondary growth in dicotyledonous stems?

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:

From where does the secondary meristem originate?