What is/are true about heartwood?
$I.$ It does not help in water conduction.
$II.$ It is also called alburnum.
$III.$ It is dark in colour but very soft.
$IV.$ It has tracheary elements, which are filled with tannin, resin, etc.
$II, III$ and $IV$
$I$ and $IV$
$II$ and $IV$
$I, II$ and $III$
Cork is used as the stopper for bottles, for shock absorption and insulation because of
Which of the following is true for the dicot roots?
Tissue present in an annual ring is
The function of cork cambium $(phellogen)$ is to produce