Photobiology — DU B.Sc. (Hons) Biological Sciences Previous Year Question Papers

Name of the. Paper : Photobiology This paper contains six questions. Answer any foz4r questions`. All parts of a question should be answered together. . Attempt e,ach new question `on a fresh page. ` (I.I.i.) Reaction center (I.I;) Latitudinal diversfty gradient (I;) Absorption spectrum (b) Expand the following : (c). Give major contributions of the following scientists ; (i) Melvin Calvin (ii) Garner and Allard (üi) Raphael Dubois 2. Comment briefly (any five): (i) Chana and bean seeds when germinated in dark conditions produce yellow straw colored seedlings. (ii) Rubisco enzyme is activated in the presence of light. - (ILL) If the length of night is disturbed by a flash of light, the SDP plants do not produce flowers. (io) Serotonin plays an important role in healtly sleep cycles. (u) Humans native to equatorial region have a darker skin compared to their European counterparts. (vi) Bioluminescence is more prevalent in marine world. 3. (cb) Why is calvin cycle also.called c3 eycle?Discuss the ey.cle in detafl. 8 (8) Describe the different cell types in human retina and` explain their function s. 7 4. (a!) Define circadian rhythms and explain its ,inportant characteristics. Add a note on Jet Lag. 8 (8) "The initial incorporation of carbon. dioxide by some plants utilizes an additional pathway involving 4-carbon molecules." Based on the given statement, answer the questions below. : (i) What pathway is this? (£Z) Describe the anatomy of a typical -leaf that exhibits this pathw-ay. (jj£) What is its ecological significance ? (a) Explain the difference between morphological apd physiological color (a) What are the *faree types ofuvrradiation? Which among them.reaches the earths surface ? 6. Write short notes on any *bree : (jj) Non-`cyclic photophosphorylation Gz.i) .Behavioral adaptations to extreme tight conditions .. (I.I;) Functions of bioluminescence.