Engelmann's Action Spectrum Experiment — NEET Biology
📚 Practice ConceptNow consider the interesting experiments done by T.W Engelmann (1843 – 1909). Using a prism he 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 O₂ evolution. He observed that the bacteria accumulated mainly in the region of blue and red light of the split spectrum. A first action spectrum of photosynthesis was thus described. It resembles roughly the absorption spectra of chlorophyll a and b (discussed in section 11.4).
Which of the following statements regarding T.W. Engelmann's experiment are correct? S1: He utilized a prism to separate white light into its spectral components. S2: The photosynthetic organism used was a filamentous green alga, Cladophora. S3: Aerobic bacteria accumulated primarily in regions of the spectrum where oxygen concentration was lowest. S4: His experiment provided the first action spectrum of photosynthesis, resembling the absorption spectra of chlorophyll a and b. S5: The highest accumulation of bacteria was observed in the green and yellow light regions.
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