Q4. Assertion: interfascicular cambium is formed by dedifferentiation. Reason: it arises from fully differentiated parenchyma cells that regain the capacity to divide. Are both true, and does the reason explain the assertion?
Both are true, and the reason explains the assertion (NCERT page 172).
Q5. What would you call parenchyma cells that are made to divide under controlled laboratory conditions during plant tissue culture, and what do they form?
They are dedifferentiated cells; they form a callus, a mass of undifferentiated cells (NCERT pages 172 and 175).
Q6. Name two tissues of a woody dicot that are products of redifferentiation.
Any two of these: secondary xylem and secondary phloem, from the vascular cambium (NCERT Chapter 6, page 73); and, beyond the NCERT text, cork and phelloderm, from the cork cambium (Shipunov, Introduction to Botany, section 7.1, and section 5.1.5). The idea of redifferentiation is from NCERT page 172.
Q7. Besides its meristem of origin, what else decides the final structure of a plant cell at maturity?
Its location in the organ: for example, cells produced on the root-cap side of the root apical meristem become root-cap cells, and those pushed to the periphery become epidermis (NCERT page 172).