explain the secondary growth in roots and stems
Please refer the link:
https://www.meritnation.com/ask-answer/question/explain-secondary-growth-in-dicot-root-with-a-diagram/anatomy-of-flowering-plants/9054989
https://www.meritnation.com/ask-answer/question/explain-the-process-of-secondary-growth-in-stems-of-woody/anatomy-of-flowering-plants/6329560
https://www.meritnation.com/ask-answer/question/explain-secondary-growth-in-dicot-root-with-a-diagram/anatomy-of-flowering-plants/9054989
https://www.meritnation.com/ask-answer/question/explain-the-process-of-secondary-growth-in-stems-of-woody/anatomy-of-flowering-plants/6329560