Question

For the process of photosynthesis, all except one of the following items are essential. Point out the exceptions.
(A) water and minerals
(B) light and chlorophyll
(C) $C{O_2}$ and optimum temperature
(D) oxygen and sucrose

Answer 1

Photosynthesis is the process where green plants and certain other organisms transform light energy into chemical energy. In this process, reaction centers play a major role.

Complete step by step answer: Photosynthesis is largely responsible for producing and maintaining the oxygen content of the earth’s atmosphere and supplies most of the energy necessary for life on earth.
Though photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called ‘reaction centers’. The reaction showing the type of photosynthesis that occurs in plants:
$6C{O_2} + 6{H_2}O \to {C_6}{H_{12}}{O_6} + 6C{O_2}$
The first photosynthetic organisms probably evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen or hydrogen sulphide, as sources of electrons rather than water. The chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water. The sunlight is very important for this process as it activates the electrons and chlorophyll being the site of photosynthesis plays a major role. Water and minerals present in the soil provide energy for growth so that the process occurs successfully.
Hence, the correct answer is option (D). oxygen and sucrose

Note: In plants, algae, and cyanobacteria, long term energy storage in the form of sugars is produced by a subsequent sequence of light-independent reactions called the ‘Calvin cycle’.