Notes from NEET topper
Steps of Secondary Growth
Secondary growth, typical in dicots and gymnosperms, involves the thickening of stems and roots. It occurs through the following steps:
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Activation of Vascular Cambium: A ring of vascular cambium, which initially appears between the primary xylem and phloem, becomes active.
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Lateral Meristem Growth: The cambium, a lateral meristem, starts producing new cells.
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Formation of Secondary Xylem and Phloem: Cells on the inside of the cambium ring differentiate into secondary xylem (wood), while those on the outside differentiate into secondary phloem.
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Cork Cambium Formation: As the stem or root widens, the epidermis is replaced by a secondary protective layer formed by the cork cambium.
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Development of Bark: The cork cambium produces cork cells towards the outside, forming the bark.
