Regarding the overall control of plant growth and development, which statements are true?
a. The role of PGRs is the only form of intrinsic control in plant development.
b. Plant growth and development are under the control of both intrinsic and extrinsic factors.
c. Intrinsic factors include genomic control and intercellular factors like PGRs.
d. Extrinsic factors include light, temperature, water, oxygen, and nutrition.
e. Many extrinsic factors, such as temperature and light, control plant growth and development via PGRs.
f. Events like vernalization, flowering, dormancy, and seed germination can be influenced by extrinsic factors acting through PGRs.
g. Development in plants is a simple process controlled by a single factor at a time.
