Question

Select the correct sequence of experiments that led to gradual understanding of photosynthesis in green plants.

• A. Production of glucose $\rightarrow$ role of air $\rightarrow$ release of oxygen $\rightarrow$ absorption spectra of chlorophyll a and b
• B. Absorption spectra of chlorophyll a and b $\rightarrow$ production of glucose $\rightarrow$ release of oxygen $\rightarrow$ role of air
• C. Role of air $\rightarrow$ release of oxygen $\rightarrow$ production of glucose $\rightarrow$ absorption spectra of chlorophyll a and b
• D. Release of oxygen $\rightarrow$ production of glucose $\rightarrow$ absorption spectra of chlorophyll a and b $\rightarrow$ role of air

Hint:

Historical order of photosynthesis discovery: Air role $\rightarrow$ Oxygen release $\rightarrow$ Food production $\rightarrow$ Chlorophyll absorption study.

Answer 1

The Correct Option is C

Concept: The understanding of photosynthesis developed gradually through contributions of many scientists. Important discoveries happened chronologically. Scientists first studied the role of air in plant growth, then oxygen release, then formation of glucose as food, and later chlorophyll absorption spectra. Thus historical order matters.

Step 1: Identify earliest discovery.
Jan Ingenhousz and Joseph Priestley studied the role of air and showed plants restore air quality. This established the role of air in photosynthesis. Hence first stage: Role of air

Step 2: Identify second discovery.
Further experiments showed that green plants release oxygen during photosynthesis. This established oxygen evolution. Hence second stage: Release of oxygen

Step 3: Identify later discoveries.
Scientists later discovered that photosynthesis produces glucose as stored chemical energy. Afterward, chlorophyll pigments were studied and their absorption spectra were determined. Hence sequence becomes \[ \text{Role of air} \rightarrow \text{Release of oxygen} \rightarrow \text{Production of glucose} \rightarrow \text{Absorption spectra} \]

Step 4: Match options.
Option (C) matches perfectly. Therefore \[ \boxed{\text{Option (3)}} \]