EVERYDAY SCIENCE

Detailed explanation-1: -Plants perform photosynthesis only in the presence of sunlight, i.e, during day. Respiration is a metabolic process which occurs throughout the day. So respiration and photosynthesis both occur during the day, but only respiration occurs at night.

Detailed explanation-2: -Answer and Explanation: The light reactions of photosynthesis that create energy from sunlight can only occur during the day, but the dark reactions (Calvin cycle) can occur both day and night.

Detailed explanation-3: -In most plants, photosynthesis fluctuates throughout the day as stomata open and close. Typically, they open in the morning, close down at midday, reopen in late afternoon and shut down for good in the evening. Carbon dioxide is plentiful in the air, so it is not a limiting factor in plant growth.

Detailed explanation-4: -Photosynthesis is not performed by plants at night. Plants can only undergo photosynthesis at night if they are exposed to the appropriate wavelengths of artificial light. With the help of the chlorophyll pigment, light energy is absorbed. By the process of photosynthesis, light energy is turned into chemical energy.

Detailed explanation-5: -The main factors affecting rate of photosynthesis are light intensity, carbon dioxide concentration and temperature.