Extrastelar secondary growth takes place by:
1.  Vascular cambium
2.  Phellogen
3.  Phellem
4.  Phelloderm

The periderm includes:
1.  Secondary phloem
2.  Cork
3.  Cambium
4.  All of these

The main function of lenticel is:
1. Transpiration
2. Guttation
3. Gaseous exchange
4. Bleeding