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