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Part 091 – Biology Previous Year Questions

Q1. Dialysis is used to perform the function of—
(a) Lungs (b) Heart
(c) Liver (d) Kidneys
Ans: (d) Dialysis is the artificial process of getting rid of waste (diffusion) and unwanted water (ultra-filtration) from the blood. This process is naturally done by our kidneys. It is the artificial replacement for lost kidney function.

Q2. Presticides are used to destroy

(a) micro-organisms
(b) poisonous substances in soil
(c) poisonous plants
(d) insects
Ans: (d) A pesticide is generally a chemical or biological agent (such as a virus, bacterium, antimicrobial or disinfectant) that through its effect deters, incapacitates, kills or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes (roundworms), and microbes.

Q3. What is the common in AIDS, mumps and poliomyelitis?

(a) Young children get affected most readily
(b) No effective vaccine has yet been developed for them
(c) These are caused by viruses
(d) Their germs can be transmitted through blood transfusions
Ans: (c) Human immunodeficiency virus (HIV) is a lentivirus (a member of the retrovirus family) that causes acquired immunodeficiency syndrome (AIDS). Mumps (epidemic parotitis) is a viral disease of the human species, caused by the mumps virus. Poliomyelitis is an acute, viral, infectious disease spread from person to person, primarily via the fecal-oral route.

Q4. Which enzyme converts proteins?

(a) Pepsin (b) Trypsin
(c) Erepsin (d) Enterokinase
Ans: (b) Trypsin is a serine protease found in the digestive system of many vertebrates, where it hydrolyses proteins. Trypsin in the duodenum catalyses the hydrolysis of peptide bonds so that proteins can be broken down into smaller peptides. These peptides may then be further hydrolyzed into amino acids by other proteases before they enter the blood stream.

Q5. The deficiency of iron in man result in

(a) Anaemia (b) Night blindness
(c) Scurvy (d) Rickets
Ans: (a) Anaemia is a condition in which the number of red blood cells or their oxygen-carrying capacity is insufficient to meet physiologic needs, which vary by age, sex, altitude, smoking, and pregnancy status. Iron deficiency is thought to be the most common cause of anaemia globally.

Q6. Protein which renders a cell less susceptible to attack by viruses is called—

(a) Actomyosin
(b) Chloromycetin
(c) Hybridoma
(d) Inferon
Ans: (d) Interferons are proteins which render the cells less susceptible to attack by viruses. Interferons are proteins made and released by host cells in response to the presence of pathogens such as viruses, bacteria, parasites or tumor cells.

Q7. Haemophilia is mostly associated with

(a) Labourers
(b) Royal families
(c) Miners
(d) Sportsmen
Ans: (b) Hemophilia is a group of hereditary genetic disorders that impair the body’s ability to control blood clotting or coagulation, which is used to stop bleeding when a blood vessel is broken. It has been associated with royal families due to inbreeding, and is sometimes called the ‘Royal Disease,’ Queen Victoria of England had this disease. However, it can occur in any family as a result of genetic mutation or a change in the genetic code.

Q8. Approximately how many times each day, do our heart valves open and close normally?

(a) 10,000 times
(b) 1,00,000 times
(c) 1,50,000 times
(d) 2,00,000 times
Ans: (b) The opening and closing of heart valves is known as a heartbeat. The average human heart beats 100,000 times per day.

Q9. Normal blood pressure of man is

(a) 80/120 mm Hg
(b) 90/140 mm Hg
(c) 120/160 mm Hg
(d) 85/120 mm Hg
Ans: (a) Normal blood pressure is considered to be at or below 120 over 80 (120/80). Normally, blood pressures are usually categorized into three groups: low (90/60 or lower), high (140/90 or higher), and normal (values above 90/60 and below 130/80).

Q10. Sugarcane plants are usually propagated by vegetative means because

(a) they do not produce seeds
(b) it is possible to maintain genetic quality
(c) the incidence of disease may be reduced
Ans: (a) Vegetative reproduction is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores. The methods of vegetative propagation include cutting, vegetative apomixis, layering, division, budding, grafting and tissue culture.

Q11. The pigment involved in photosynthetic activity is

(a) anthocyanin
(b) fucxanthin
(c) carotenoid
(d) chlorophyll
Ans: (d) Chlorophyll is an extremely important bio-molecule, critical in photosynthesis, which allows plants to absorb energy from light. Chlorophyll absorbs light most strongly in the blue portion of the electromagnetic spectrum, followed by the red portion. However, it is a poor absorber of green and near-green portions of the spectrum, hence the green color of chlorophyllcontaining tissues.

Q12. Free-living nitrogen fixing microorganisms are

(a) Rhizobia
(b) Soil fungi
(c) Vesicular arbuscular mycorrhiza
(d) Blue green algae
Ans: (a) Rhizobia are soil bacteria that fix nitrogen (diazotrophs) after becoming established inside root nodules of legumes. Rhizobia require a plant host; they cannot independently fix nitrogen. In general, they are Gram-negative, motile, non-sporulating rods.

Q13. Vegetable oils are converted into solid fat (ghee) by

(a) Hydrolysis
(b) Addition of agar
(c) Oxidation using air and a catalyst
(d) Hydrogenation
Ans: (d) Hydrogenation – to treat with hydrogen – is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst. The largest scale application of hydrogenation is for the processing of vegetable oils (fats to give margarine and related spreads and shortenings). Typical vegetable oils are derived from polyunsaturated fatty acids (containing more than one carbon-carbon double bonds).

Q14. A drug which helps in controlling fever is

(a) Ibuprofen
(b) Penicillin
(c) Paracetamol
(d) Corticosteroid
Ans: (c) Paracetamol is a widely used over-the-counter analgesic (pain reliever) and antipyretic (fever reducer). The World Health Organization (WHO) recommends that paracetamol only be used to treat fever in children if their temperature is greater than 38.5 °C.

Q15. Identify the correct stateme-nt with respect to Biogas.

(a) Mixture of gases from volcanoes
(b) Gas produced from certain crude oil wells
(c) Gas produced by incomplete combustion of biomass
(d) Gas produced by fermen-tation of biomass
Ans: (d) Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops. Biogas comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes.

Q16. Aspartame is the name of a product used by diabetic patients as a sweetening agent.
It belongs to the class of—

(a) Carbohydrates
(b) Peptides
(c) Polyhydric alcohols
(d) Alkaloids
Ans: (b) Aspartame is an artificial, non-saccharide sweetener used as a sugar substitute in some foods and beverages. It is a methyl ester of the aspartic acid/phenylalanine dipeptide. Under strongly acidic or alkaline conditions, aspartame may generate methanol by hydrolysis. Under more severe conditions, the peptide bonds are also hydrolyzed, resulting in the free amino acids.

Q17. Which one of the following four secretions, is different from the remaining three in regard to its mode of transport from the source gland to the site of action?

(a) Saliva (b) Sweat
(c) Bile (d) Epinephrine
Ans: (c) Saliva: secreted by the salivary glands; Sweat: achieved by the water-rich secretion of the eccrine glands; Epinephrine: also known as adrenaline is a hormone and a neurotransmitter; and Bile: a bittertasting, dark green to yellowish brown fluid, produced by the liver that aids the process of digestion of lipids in the small intestine. Bile is the odd one among all four as it is secreted by liver, while others are secreted by glands.

Q18. What is true about viruses without exception?

(a) They contain a core of RNA
(b) They can infect bacteria
(c) They cannot produce antibodies
(d) They can multiply only in host cells
Ans: (d) Viruses do not contain enzymes for energy production or protein synthesis. For a virus to multiply, it must invade a host cell and direct the host’s metabolic machinery to produce viral enzymes, viral proteins, and copies of its nucleic acid, using the host cell’s ATP to power the reactions.

Q19. Haemoglobin is a

(a) protein
(b) carbohydrate
(c) fat
(d) vitamin
Ans: (a) Hemoglobin is the iron-containing oxygen-transport metal-protein in the red blood cells of all vertebrates which carries oxygen from the respiratory organs (lungs or gills) to the rest of the body (i.e. the tissues) where it releases the oxygen to burn nutrients to provide energy to power the functions of the organism, and collects the resultant carbon dioxide to bring it back to the respiratory organs to be dispensed from the organism.

Q20. Natural organic fertilizers are found to be better then chemical fertilizers because

(a) chemical fertilizers are less productive
(b) organic fertilizers are more productive
(c) organic fertilizers sustain soil productivity
(d) chemical fertilizers are toxic
Ans: (c) Organic fertilizers like compost are either soil conditioners or growth enhancers. They sustain crop yields and soil productivity in intensive cropping systems which leave low organic residues on the soil.

Q21. Which of the following groups of organisms digest their food before it actually enters the organism?

(a) Bacteria and Protozoa
(b) Bacteria and Fungi
(c) Fungi and Protozoa
(d) Mucor and Rhizopus
Ans: (b) Decay is an essential life process, which helps to digest food and recycle materials. Bacteria and fungi are the main groups of decomposer. They release enzymes to break down compounds, so that they can absorb the nutrients. Organisms that feed on dead material in this way are called saprophytes.

Q22. The average heartbeat rate per minute in a normal person is

(a) 82 (b) 92
(c) 72 (d) 98
Ans: (c) The average heart rate for adult humans is about 70 to 75 beats per minute in a normal relaxed mode. The “normal” heart beat rate is taken to be “72 beats per minute.”

Q23. Metabolism is referred to as

(a) synthesis of biomolecules
(b) breaking-down of biomolecules
(c) synthesis and breaking down of biomolecules
(d) recycling of biomolecules
Ans: (c) Metabolism is the sum total of chemical reactions occurring in cells. It includes both anabolism, the synthesis of the biomolecules (e.g., protein synthesis, DNA replication, glucose synthesis in plants) and catabolism, the degradation of molecules usually for the production of energy (e.g., glycolysis, Krebs Cycle). Metabolism is carried out by specific enzymes which catalyze each step of a long series of reactions.

Q24. The enzymes are basically

(a) carbohydrates
(b) lipids (c) proteins
(d) amino acids
Ans: (c) Enzymes are in general globular proteins and range from just 62 amino acid residues in size, for the monomer of 4-oxalocrotonate tautomerase, to over 2,500 residues in the animal fatty acid synthase. The activities of enzymes are determined by their three-dimensional structure.

Q25. Why death of fish is more common during summer than in winter?
It is because of

(a) shortage of food
(b) concentration of toxins
(c) depletion of oxygen
(d) spread of diseases
Ans: (c) Fish die more in summer due to oxygen depletion which refers to low levels of dissolved oxygen (DO) in water. Warm water is much less capable of holding oxygen gas in solution than cool water. For example, water that is 90° F can only hold 7.4 mg/L DO at saturation, whereas water that is 45° F can hold 11.9 mg/L DO at saturation. This physical phenomenon puts the fish in double jeopardy because at high water temperatures their metabolic rates increase, hence their physiologic demand for oxygen increases.

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