Secodary xylem and phloem in dicot stem are produced by
Phellogen
Vascular cambium
Apical meristems
Axillary meristems
As we learnt in
Differentiation of vascular tissue in pteridophyta -
In xylem, true vessel are absent, tracheids present.
In phloem, companion cell and sieve tubes are absent, instead sieve cell are present.
-
The vascular cambium is the main growth layer in the stems and roots of many plants, specifically in dicots. It produces xylem on the inside and phloem on the outside.
Option 1)
Phellogen
This is incorrect.
Option 2)
Vascular cambium
This is correct.
Option 3)
Apical meristems
This is incorrect.
Option 4)
Axillary meristems
This is incorrect.