(N/A) $\rightarrow$ Primary Growth: The increase in the length of the root and stem due to the activity of apical meristems is called primary growth.
$\rightarrow$ Secondary Growth: The increase in the girth or thickness of the plant body,occurring after the completion of primary growth in dicotyledonous plants,is known as secondary growth.
$\rightarrow$ Types of Secondary Growth: Secondary growth is primarily facilitated by two types of lateral meristems:
$1$. Vascular cambium: Responsible for the production of secondary xylem and secondary phloem.
$2$. Cork cambium (Phellogen): Responsible for the production of periderm (cork and secondary cortex).