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Part 098 – Biology Previous Year Questions

Q1. Hypoglycemia refers to
(a) high salt concentration in blood
(b) high blood sugar level
(c) high blood pressure
(d) low sugar level in blood
Ans: (d) Hypoglycemia is an abnormally diminished content of glucose in the blood. The term literally means “low sugar blood”. It can produce a variety of symptoms and effects but the principal problems arise from an inadequate supply of glucose to the brain, resulting in impairment of function.

Q2. The primary source of carbohydrates are

(a) Marine animals
(b) Plants
(c) Coal-tar
(d) Crude oil
Ans: (b) Plants are the primary sources of carbohydrates. They produce carbohydrates by photosynthesis which is the source of energy for nearly all life on earth, either directly, through primary production, or indirectly, as the ultimate source of the energy in their food.

Q3. Which animal may suffer from foot and mouth disease ?

(a) Cattle
(b) Cattle and sheep
(c) Cattle and pigs
(d) Cattle, sheep and pigs
Ans: (b) Foot-and-mouth disease is an infectious and sometimes fatal viral disease that affects clovenhoofed animals, including domestic and wild bovids. The virus causes a high fever for two or three days, followed by blisters inside the mouth and on the feet that may rupture and cause lameness. Susceptible animals include cattle, water buffalo, sheep, goats, pigs, antelope, deer, and bison.

Q4. What does enamel cover ?

(a) Crown of the tooth
(b) Dentin on all sides
(c) Cementum
(d) Cementum and partly dentin
Ans: (a) The basic unit of enamel is called an enamel rod which is a tightly packed mass of hydroxyapatite crystals in an organized pattern. In cross section, it is best compared to a keyhole, with the top, or head, oriented toward the crown of the tooth, and the bottom, or tail, oriented toward the root of the tooth.

Q5. The antibiotic Ampicillin is :

(a) a synthetic drug
(b) obtained from a bacterium
(c) obtained from a plant extract
(d) a semi-synthetic drug
Ans: (b) Ampicillin is an antibiotic made from bacteria. Belonging to the penicillin group of beta-lactam antibiotics, ampicillin is able to penetrate Grampositive and some Gram-negative bacteria. It differs from penicillin only by the presence of an amino group. That amino group helps the drug penetrate the outer membrane of gram-negative bacteria.

Q6. Opium is a plant product obtained from

(a) dried leaves (b) dried latex
(c) roots (d) stem bark
Ans: (b) Opium is the dried latex obtained from the opium poppy. Opium contains approximately 12% morphine, an alkaloid, which is frequently processed chemically to produce heroin for the illegal drug trade. The latex also includes codeine and non-narcotic alkaloids such as papaverine, thebaine and noscapine.

Q7. Drying oils contain a fairly large proportion of

(a) fats
(b) proteins
(c) saturated fatty acids
(d) unsaturated fatty acids
Ans: (d) They contain a high percentage of “polyunsaturates” (polyunsaturated fatty acids). Most drying oils owe their drying properties to the presence of a large percentage of linolenic acid (which derives its name from “linseed”), which is highly unsaturated.

Q8. Which virus from the following combinations is contagious for human beings ?

(a) H5N1 (b) H1N5
(c) H2N3 (d) H4N2
Ans: (a) A bird-adapted strain of H5N1, called HPAI A(H5N1) for “highly pathogenic avian influenza virus of type A of subtype H5N1”, is the causative agent of H5N1 flu, commonly known as “avian influenza” or “bird flu”. It is enzootic in many bird populations, especially in Southeast Asia. One strain of HPAI A(H5N1) is spreading globally after first appearing in Asia.

Q9. Which of the following is a deficiency disease ?

(a) Asthma (b) Jaundice
(c) Scurvy (d) Cancer
Ans: (c) Scurvy is caused by the deficiency of Vitamin C. Vitamin. This causes muscle weakness, joint pain and problems with wound healing. It can also lead to loose teeth, bleeding and swollen gums, easily bruised skin and fatigue, and sometimes depression.

Q10. Which of the following animals has a clitellum ?

(a) Millipede (b) Centipede
(c) Earthworm (d) Ringworm
Ans: (c) A clitellum is part of a of the reproductive system of clitellates, a subgroup of annelids which contains oligochaetes (earthworms) and hirudineans (leeches). The clitellum is a thick, saddle-like, ring found in the epidermis (skin) of the worm, usually with a light colored pigment. To form a cocoon for its eggs, the clitellum secretes a viscous fluid.

Q11. The number of chromosomes present in the somatic cell of the human cell is

(a) 23 (b) 44
(c) 46 (d) 92
Ans: (c) Human cells have 23 pairs of chromosomes (22 pairs of autosomes and one pair of sex chromosomes), giving a total of 46 per cell.

Q12. Which one of the following organs excretes water, fat and various catabolic wastes ?

(a) Kidney (b) Skin
(c) Spleen
(d) Salivary glands
Ans: (a) The kidneys are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and regulation of blood pressure (via maintaining salt and water balance). They serve the body as a natural filter of the blood, and remove wastes which are diverted to the urinary bladder.

Q13. The trace metal present in insulin is

(a) iron (b) zinc
(c) cobalt (d) manganese
Ans: (b) Trace elements play important role in Insulin metabolism. The relationship between diabetes, insulin and zinc (Zn) is complex with no clear cause and effect relationships. Several of the complications of diabetes may be related to increased intracellular oxidants and free radicals associated with decreases in intracellular Zn and in Zn dependent antioxidant enzymes.

Q14. Which of the following metals is present in chlorophyll?

(a) Beryllium (b) Magnesium
(c) Calcium (d) Barium
Ans: (b) Chlorophyll is a chlorin pigment, which is structurally similar to and produced through the same metabolic pathway as other porphyrin pigments such as heme. At the center of the chlorin ring is a magnesium ion.

Q15. What vessel carries the venous blood to the lungs for oxygenation ?

(a) Pulmonary arteries
(b) Pulmonary veins
(c) Pulmonary arterio-venous shunt
(d) Right ventricle
Ans: (a) Pulmonary arteries carry venous blood from the right ventricle of the heart to the lungs. They carry deoxygenated blood to the lungs, where it releases carbon dioxide and pick up oxygen during respiration.

Q16. Quinine, the commonly used drug to treat malaria, is obtained from a plant. What part of the plant yields the drug ?

(a) Leaves (b) Fruits
(c) Root (d) Stem bark
Ans: (d) Quinine, as a component of the bark of the cinchona tree, was used to treat malaria from as early as the 1600s. The bark of trees in this genus is the source of a variety of alkaloids, the most familiar of which is quinine, an antipyretic (anti-fever) agent.

Q17. Most fish do not sink in water because of the presence of

(a) air sinuses
(b) buoyant scales on the body
(c) swim bladder
(d) swimmerets
Ans: (c) Most fish are able to control their bouyancy with a swim bladder (an internal sac they can fill with gas or water) or by other means, so that they have a specific gravity exactly the same as the water they swim in. By small adjustments to their buoyancy, they can float to a higher level or sink lower with a very small expenditure of energy.

Q18. Heavy alcohol consuming people generally die of

(a) blood cancer
(b) cirrhosis
(c) liver or stomach cancer
(d) weakening of heart muscles leading to cardiac arrest
Ans: (b) Cirrhosis is scarring of the liver and poor liver function. It is the final phase of chronic liver disease which may result from a history of excess drinking habits. Cirrhosis is most commonly caused by alcoholism, hepatitis B and hepatitis C, and fatty liver disease.

Q19. Chocolates can be bad for health because of a high content of

(a) cobalt (b) nickel
(c) zinc (d) lead
Ans: (d) Chocolate absorbs lead from the environment during production. Recently there has been concern of mild lead poisoning for some types of chocolate.

Q20. Which carbohydrate is used in silvering of mirrors ?

(a) Fructose (b) Sucrose
(c) Glucose (d) Starch
Ans: (c) Glucose is used in silvering of mirror as a reducing agent. Aldehydes such as glucose reduce Ag+ (aq) ions to metallic silver. They themselves are oxidised to carboxylate ions.

Q21. When a child is born, what happens to its blood circulation ?

(a) Its blood flows for the first time
(b) Its blood reverses its flow through the heart
(c) Its blood ceases to pass from one atrium to the other
(d) Its blood carries wastes for the first time
Ans: (d) The Fetal circulatory system is unique during pregnancy before the lungs first come into use at birth. Its circulatory system must reorient itself to send all the blood through the lungs to receive oxygen. The baby is cut off from the placenta, which was previously its only source of nourishment. The blood vessels that ran through the umbilical cord constrict and close. All this happens in a few moments when the baby is born.

Q22. Which virus from the following combinations is contagious for human beings

(a) H5N1 (b) H2N3
(c) H4N1 (d) H4N2
Ans: (a) A bird-adapted strain of H5N1, called HPAI A(H5N1) for “highly pathogenic avian influenza virus of type A of subtype H5N1”, is the causative agent of H5N1 flu, commonly known as “avian influenza” or “bird flu”.

Q23. Cuscuta is a

(a) partial stem parasite
(b) complete stem parasite
(c) partial root parasite
(d) complete root parasite
Ans: (b) Cuscuta (Dodder) is a genus of about 100-170 species of yellow, orange or red (rarely green) parasitic plants. Dodders are supremely adapted for a life of plunder and pillage. Reduced in form to scrambling and twining threads, they appear to be completely leafless, although closer inspection reveals tiny scale leaves pressed close to the stems. So it is a stem parasite.

Q24. Plants differ from animals in having

(a) locomotion
(b) metabolism
(c) localised growth
(d) catabolism
Ans: (c) Plants produce new cells and grow only in their shoot and root apical meristems and leaf primordia; this is localized growth. In contrast, all parts of an animal’s body grow (diffuse growth). From the time we are embroys until we are about 18 years old, all parts of our body grow simultaneously. Due to a plant’s localized growth, an individual plant can have older, completely mature and highly functional leaves at the same time that it is still producing new leaves.

Q25. The function of the heart is to

(a) Supply oxygen to the tissues
(b) carry carbon dioxide from the tissues
(c) throw away waste materials
(d) pump blood to different parts of the body
Ans: (d) The heart is a hollow muscle that pumps blood throughout the blood vessels by repeated, rhythmic contractions. In mammals, the function of the right side of the heart (see right heart) is to collect deoxygenated blood, in the right atrium, from the body (via superior and inferior vena cavae) and pump it, through the tricuspid valve, via the right ventricle, into the lungs (pulmonary circulation) so that carbon dioxide can be dropped off and oxygen picked up (gas exchange). This happens through the passive process of diffusion.

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