Test: Photosynthesis - NEET MCQ

Engelmann used a prism to split light into its spectral components, and then illuminated a green alga, Cladophora, placed in a suspension of aerobic bacteria.

The bacteria were used to detect the sites of oxygen evolution. He observed that bacteria mainly accumulated in the region of blue and red light of the split spectrum, thus giving the first action spectrum of photosynthesis.

Line in NCERT: "Using a prism he split light into its spectral components and then illuminated a green alga, Cladophora, placed in a suspension of aerobic bacteria. A first action spectrum of photosynthesis was thus described."

KOH (Potassium Hydroxide) absorbs carbon dioxide. The leaf inside the bottle containing KOH solution does not become blue-black when compared with the leaf which is exposed to atmospheric air. This shows that carbon dioxide is necessary for photosynthesis.

Line in NCERT: "Another experiment you may have carried out where a part of a leaf is enclosed in a test tube containing some KOH soaked cotton (which absorbs CO2), while the other half is exposed to air."

Jan Ingenhousz is best known for his discovery of photosynthesis, the process by which green plants absorb carbon dioxide in the presence of sunlight and release oxygen

Line in NCERT: "Ingenhousz in an elegant experiment with an aquatic plant showed that in bright sunlight, small bubbles were formed around the green parts while in the dark they did not."

(Total molecules utilized are 18 and produced are 13. Therefore total is 31) 

The chemiosmotic hypothesis explains how cells produce energy. It describes how, similar to respiration, photosynthesis also uses this method.

Line in NCERT: "Like in respiration, in photosynthesis too, ATP synthesis is linked to development of a proton gradient across a membrane."