BOTANY

Detailed explanation-1: -The secondary growth of plants increase in stem thickness and it is due to the activity of the lateral meristems, which are absent in herbs or herbaceous plants. There are two types of lateral tissues involved in secondary growth, namely, vascular cambium and cork cambium.

Detailed explanation-2: -Secondary growth involves the thickening of the plant axis through the activity of lateral meristems. The end result of secondary growth is increased amounts of vascular tissue. As plants grow larger, more vascular tissue is needed for water conduction and the transport of nutrients.

Detailed explanation-3: -It is the result of cell division in the shoot apical meristem. Secondary growth is characterized by an increase in thickness or girth of the plant.