what is the effect of light intensity, temperature and concentration of carbon dioxide on the rate of photosynthesis?
Increasing light intensity will increase photosynthesis, as will increasing carbon dioxide. Temperature will increase photosynthesis up to a point, but above about 40oC the cells enzymes will be denatured and photosynthesis will (eventually) stop. Note, though, that ALL of these factors affect photosynthesis at the same time, but at any one time only one will be 'limiting' e.g. increasing light intensity SHOULD increase photosynthesis, but it won't if there is very little CO2 or if the temperature is very low, because those factors will then stop photosynthesis increasing nomatter how much light there is.