(i) Photosynthesis started at 7.00 am
(ii) The rate of photosynthesis was greatest at 12 noon as the amount of carbon dioxide taken in was greatest at that time.
(iii) At 9.00 pm, it was dark.
(iv) (a) Through stomata
(b) It is reduced to carbohydrates.
(v) Factors which affect the rate of photosynthesis are light, humidity, temperature and concentration levels of carbon dioxide in the air. There are optimum levels for each factor above which photosynthesis will start to decrease.