(2) The mode of cell water absorption is osmosis, provided that the semipermeable membrane and concentration difference make water transport from low concentration to high concentration; Root tip mature cells can absorb water from soil and must have selective permeability of protoplasm and maintain activity. In addition, the concentration of cell fluid is higher than that of external solution.
(3) The purpose of repeated experiments is to eliminate the influence of accidental factors on experimental results, thus reducing experimental errors.
(4) According to Figure 8:00- 12:00, with the increase of light intensity, the absorption of carbon dioxide increases; During the period of 12: 00 ~ 14: 00, the light intensity was too strong, the transpiration water loss increased, the stomata closed, and the carbon dioxide source decreased, which decreased the photosynthetic rate.
Therefore, the answer is: (1) Discuss the effect of soil moisture on the photosynthesis of Dioscorea nipponica Makino.
(2) that cell whose cell fluid concentration is higher than that of soil solution have normal protoplasm.
(3) reduce the experimental error
(4) light intensity? Some pores are closed, resulting in reduced absorption of carbon dioxide.