Photosynthesis proceeds in sequence of A) Dark phase and light phase B) Light phase alone C) Light phase and dark phase D) Dark phase alone
Option C) Photosynthesis is an anabolic process happening in green plants during which plant body synthesizes its own food material by taking carbon dioxide from atmosphere and water from the soil in presence of sunlight. It proceeds in a sequence of light phase and dark phase. Light phase is also known as a photochemical phase because it is a light dependent phase. During this phase, the formation of high-energy chemical intermediates ATP and NADPH2 takes place. ATP and NADPH2 are the assimilatory power of photosynthesis. Light phase also includes light absorption, water splitting and release of oxygen. Two photosynthetic units called Photosystem I and Photosystem II are also involved in light phase. Dark phase is the phase which is independent of light. But, it is dependent on the products of light reaction (ATP and NADPH2). In this phase, assimilation of carbon dioxide takes place during which carbon dioxide and water combine to form glucose.
