$I.$ Annual rigs are formed as a result of seasonal environmental conditions

$II.$ Tracheids/vessels elements are larger during periods when water is abundant

$III.$ Tracheids/vessels elements have thicker wall during periods of water deprivation

$IV.$ Wood formed in the previous years is darker than newer wood

Select the combination of correct statements from the options given below

$A$ : In monocot roots, pericycle gives rise to lateral roots and cork cambium.

$R$ : It has tetrach vascular bundles usually.

Periderm includes

Seasonal activity of vascular cambium is influenced by many factors, except

Each of the following terms has some anatomical significance. What do these terms mean ? Explain with the help of line diagrams.

$(A)$ Plasmadesmoses / Plasmodesmata

$(B)$ Middle lamella

$(C)$ Secondary wall

Select the wrong statements

$I.$ Primary and secondary phloem gets crushed during secondary growth

$II.$ During secondary growth, primary xylem remains more or less intact