Question

Oxygen is one of the products of photosynthesis. Which reactant is the source for oxygen gas and how is it released?
A. Water, released when sunlight splits it into oxygen and hydrogen ions
B. Glucose, released when glucose is broken down into carbon dioxide gas, oxygen gas and water
C. Carbon dioxide, released when sunlight splits it into carbon and oxygen gas
D. Electrons, released when they strike the chloroplasts
E. NADPH, released when NADPH breaks down into its component elements

Answer 1

Term photosynthesis where photo means light and synthesis means to make, it is a process by which green plants prepare their own food by using carbon dioxide, water in presence of sunlight, and chlorophyll by releasing excess oxygen and making carbohydrates is known as photosynthesis that takes place in the chloroplast.

Complete answer:
Green plants capture the energy and convert it into chemical energy with the help of the process known as photosynthesis. The process of photosynthesis consists of reactants and by-products in which the most important reactant is ${{\text{H}}_{\text{2}}}{\text{O}}$(water). Six molecules of${{\text{H}}_{\text{2}}}{\text{O}}$ (water) and ${\text{C}}{{\text{O}}_{\text{2}}}$ (carbon dioxide) both react to form ${{\text{C}}_{\text{6}}}{{\text{H}}_{{\text{12}}}}{{\text{O}}_{\text{6}}}$(glucose) and ${{\text{O}}_{\text{2}}}$(oxygen). In the light reaction, proteolysis occurs and causing water molecules to split up into ${{\text{H}}^ + }$and ${\text{O}}{{\text{H}}^ - }$ions, and these ${\text{O}}{{\text{H}}^ - }$ions react to produce oxygen.
Green plants also possess a green pigment i.e. chlorophyll which is responsible for trapping sunlight to provide energy for the process of photosynthesis. Chlorophyll pigment then combines ${\text{C}}{{\text{O}}_{\text{2}}}$ and ${{\text{H}}_{\text{2}}}{\text{O}}$to form sugars. Leaves having more photosynthetic pigment absorb more light. Plants take carbon dioxide from the air and utilize it in this important process, and it is another essential reactant that combines with the water to form the end product of photosynthesis i.e. glucose is utilized by the plants for energy.

Hence, the correct answer is option (A).

Note: Photosynthesis is an essential process as it is the primary source of energy and for oxygen liberation which is a key to respiration which is one of the most important biological processes.