Q4. Assertion: the different shapes of buttercup leaves in air and in water are an example of plasticity. Reason: plants can follow different developmental pathways in response to their environment. Are both true, and does the reason explain the assertion?
Both are true, and the reason explains the assertion (NCERT page 173).
Q5. Through which stage does a mature plant cell pass before death, according to NCERT Figure 13.8?
Senescence (NCERT page 173).
Q6. How do many extrinsic factors such as light and temperature act on plant growth and development?
Through plant growth regulators: NCERT notes that many extrinsic factors control growth and development via PGRs (page 178).