Which of the following is produced as a by-product during the process of photosynthesis in plants?

The correct option is Oxygen.

Explanation

Photosynthesis is an anabolic process used by green plants, algae, and certain bacteria to convert light energy into chemical energy. It involves the synthesis of carbohydrates (glucose) from carbon dioxide and water in the presence of sunlight and chlorophyll.

Detailed Analysis:

• Oxygen (Correct): During the light-dependent reactions of photosynthesis, water molecules undergo photolysis (splitting in the presence of light). This process releases electrons, protons (H⁺), and molecular Oxygen (O₂). The oxygen produced is released into the atmosphere as a by-product. The general equation is represented as:
  6CO₂ + 12H₂O → C₆H₁₂O₆ + 6H₂O + 6O₂
• Nitrogen: Nitrogen is an essential macronutrient absorbed by plants from the soil (usually as nitrates or ammonium) for protein synthesis. It is not a by-product of photosynthesis.
• Urea: Urea is a nitrogenous waste product formed in the liver of ureotelic animals (mammals, amphibians) through the ornithine cycle. It is not produced by plants during photosynthesis.
• Lactic Acid: Lactic acid is typically produced during anaerobic respiration in animal muscle cells or by certain bacteria (e.g., Lactobacillus). It is not a product of plant photosynthesis.

Key Takeaway:

Oxygen is the specific gaseous by-product generated during the light reaction of photosynthesis, originating from the oxidation (splitting) of water molecules.