question_answer 23)

  Fill in the places with appropriate word/words. (a) A phase of growth which is maximum and fastest is ........... . (b) Apical dominance as expressed in dicotyledonous plants is due to the presence of more ........ in the apical bud than in the lateral ones. (c) In addition to auxin, a ........ must be supplied to culture medium to obtain a good callus in plant tissue culture. (d) ........ of a vegetative plants are the sites of photoperiodic perception.

Answer:

                (d) Fully developed leaves receive the stimulus of light photoperiodism is the effect of light and its duration on the growth and development especially flowering in plants. Even a single leaf as its part is part is capable of inducing photoperidism but very young leaves are insensitive to light. Other parts meristem flower and floral buds de not perceive the stimulus.