DHR - BRET PYQs July 2018

Pharmacology & Environmental Science

Very muscular organ used to grid food in birds is called the

The gizzard or ventriculus is a thick-walled muscular stomach in birds that grinds ingested food aided by swallowed grit, compensating for lack of teeth. Crop stores food, proventriculus secretes gastric juice, and beak captures food but does not grind.

Ref: Sturkie and Nilsson, Sturkie's Avian Physiology, 6th Edition, Chapter 16 on Gastrointestinal Tract Function, describes gizzard musculature, koilin lining, grinding action and its role in avian digestion, published by Springer Science.

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Pharmacology & Environmental Science

A sheep is called

Scientific collective terms classify sheep as ovine derived from Latin ovis, cattle as bovine, dogs as canine and pigs as swine. Using ovine correctly identifies sheep in veterinary, zoological, meat and wool literature distinguishing species-specific husbandry and anatomy.

Ref: Hafez and Hafez, Reproduction in Farm Animals, 7th Edition, Chapter 2 on Comparative Reproductive Anatomy and Livestock Terminology, lists ovine for sheep, bovine for cattle, porcine and equine classifications, published by Wiley-Blackwell Lippincott.

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Pharmacology & Environmental Science

Principal protein in milk is

Casein constitutes about 80% of total bovine milk protein, forming micelles that carry calcium and phosphate for neonate nutrition. Lactalbumin, albumin and immunoglobulins are whey proteins present in smaller amounts and do not dominate milk protein composition.

Ref: Lehninger, Nelson and Cox, Principles of Biochemistry, 7th Edition, Chapter 5 on Protein Function and Milk Proteins, explains casein micelle structure, calcium binding and nutritional role as principal milk protein, published by W.H. Freeman Macmillan.

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Pharmacology & Environmental Science

White leghorn is a breed of

White Leghorn is a highly productive Mediterranean breed of domestic chicken renowned for efficient egg production and white eggshells. It originated in Italy and dominates commercial layer poultry farming worldwide, unlike pig, dog or horse breeds which have entirely different classifications.

Ref: Banerjee, A Textbook of Animal Husbandry, 8th Edition, Chapter 12 on Poultry Breeds and Production, details White Leghorn history, performance traits, egg yield and exotic breed management in India, published by Oxford and IBH Publishing Company.

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Pharmacology & Environmental Science

Rumen is present in which for the following animals

Rumen is the large first chamber of the four-chambered stomach in ruminants like cow, hosting anaerobic microbes for cellulose fermentation. Dogs have simple stomachs, horses are hindgut fermenters with enlarged cecum, and poultry have crop and gizzard but no rumen.

Ref: Dukes, Dukes' Physiology of Domestic Animals, 13th Edition, edited by Reece, Chapter 30 on Ruminant Digestive Physiology, describes rumen anatomy, microbial fermentation, volatile fatty acid production and forestomach function, published by Cornell University Press.

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Pharmacology & Environmental Science

Which of the following is a bio-remedial technique?

Composting is a biologically mediated remediation technique where microorganisms decompose organic wastes into humus, reducing pollutants and recycling nutrients. Oxidation, reduction and sedimentation are predominantly physico-chemical treatment methods lacking microbial metabolic transformation central to bioremediation.

Ref: Atlas and Bartha, Microbial Ecology: Fundamentals and Applications, 4th Edition, Chapter 16 on Biodegradation and Bioremediation, covers composting as bioremediation, microbial decomposition and waste mineralization processes, published by Benjamin Cummings Addison Wesley.

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Pharmacology & Environmental Science

Which of the following plant/s is commonly used for biodiesel production in India?

Jatropha curcas seeds contain 30-40% non-edible oil with high oleic acid content, ideal for transesterification into biodiesel under Indian agroclimatic conditions. Calotropis and bamboo have low oil yield and are not viable commercial biodiesel feedstocks in National Biofuel Policy.

Ref: Pandey, Handbook of Plant Biotechnology and Biofuel Production, 2nd Edition, Chapter on Non-Edible Oilseed Biodiesel Crops, details Jatropha curcas agronomy, oil extraction and biodiesel conversion in India, published by CRC Press Taylor and Francis.

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Pharmacology & Environmental Science

Extinction of Dodo was mainly due to: (DROP)

As per official answer key this dropped question lists pollution as answer, though historically dodo extinction involved human hunting and introduced predators. Pollution concepts illustrate anthropogenic extinction drivers, but contemporary literature attributes Raphus cucullatus loss mainly to overexploitation and invasive species on Mauritius.

Ref: Begon, Townsend and Harper, Ecology: From Individuals to Ecosystems, 4th Edition, Chapter 16 on Extinction Causes, discusses dodo extinction narrative, human hunting, invasive species and anthropogenic loss case studies, published by Wiley-Blackwell.

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Pharmacology & Environmental Science

What changes in the plant indicate the toxic effects of SO₂?

Sulphur dioxide enters via stomata, forming sulfite and bisulfite ions that destroy chlorophyll, causing interveinal chlorosis and bleaching of leaves as characteristic toxicity symptom. Leaf fall, drooping or darkening are associated with other stresses like drought or ethylene, not specific SO2 injury.

Ref: Agrios, Plant Pathology, 5th Edition, Chapter 13 on Environmental Air Pollution Injury, describes SO2 phytotoxicity, chlorophyll bleaching, chlorosis necrosis and acid rain interactions, published by Elsevier Academic Press.

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Pharmacology & Environmental Science

Substitute of Chloro Fluoro Carbon (CFCs) used in refrigeratotrs is:

Hydrofluorocarbons, particularly HFC-134a, replaced CFCs in refrigerators because they lack chlorine and thus cause negligible ozone depletion, though they remain greenhouse gases. Methane and helium are unsuitable refrigerants, and HCFCs are transitional compounds with residual ozone depletion potential.

Ref: Masters and Ela, Introduction to Environmental Engineering and Science, 3rd Edition, Chapter 8 on Stratospheric Ozone Depletion, explains CFC phase-out, Montreal Protocol, HFC and HCFC substitutes in refrigeration technology, published by Pearson Prentice Hall.

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Pharmacology & Environmental Science

The Earth day is celebrated on:

International Earth Day is observed annually on 22nd April to promote environmental protection and awareness since 1970. March 22 is World Water Day, June 5 is World Environment Day, and May 8 is not associated with Earth Day commemorations.

Ref: Miller and Spoolman, Living in the Environment, 19th Edition, Chapter 27 on Sustainability and Environmental History, notes Earth Day establishment on April 22, Gaylord Nelson movement and annual observance, published by Cengage Learning.

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Pharmacology & Environmental Science

During photosynthesis, PS II absorbs energy at or below:

Photosystem II reaction centre chlorophyll P680 has an absorption maximum at 680 nm and cannot effectively utilize longer wavelengths. P700 belongs to Photosystem I, absorbing up to 700 nm, while 670 nm represents antenna absorption and 780 nm is beyond photosynthetically active radiation.

Ref: Taiz, Zeiger, Moller and Murphy, Plant Physiology and Development, 6th Edition, Chapter 9 on Photosynthesis Light Reactions, discusses PSII P680 absorption, Z-scheme, photochemical action spectra and energy trapping, published by Sinauer Associates Oxford.

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