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Part 074 – Biology Previous Year Questions

Q1. In the case of test tube babies
(a) egg is fertilized in the uterus.
(b) embryo completes its development in a test tube.
(c) embryo is placed in uterus after 2 months.
(d) egg is fertilized outside mother’s body.
Ans: (c) Prior of the implantation of the blastocyst the uterus of the recipi-ent mother should be made ready to receive the embryo. This is usually done with the hormonal treatment. The blastocyst is introduced into the uterus by one of the two methods – by using a catheter through the vagina and cervical canal to the womb or directly into the uterus through a cut made in the wall of the uterus. The womb of the mother under the influence of the hormones develops the endometrium and the blastocyst gets im-planted and the normal process of pregnancy continues.

Q2. The age of trees is determined by its :

(a) girth (b) height
(c) growth rings
(d) general appearance
Ans: (c) Growth rings can determine the age of the trees. Growth rings, also referred to as tree rings or annual rings, can be seen in a horizontal cross section cut through the trunk of a tree. Growth rings are the result of new growth in the vascular cambium, a layer of cells near the bark that is classified as a lateral meristem. These visible rings result from the change in growth speed through the seasons of the year, thus one ring usually marks the passage of one year in the life of the tree.

Q3. Kidney disease in man is caused by the pollutant :

(a) Cadmium (b) Iron
(c) Cobalt (d) Carbon
Ans: (a) Cadmium (Cd), a by-product of zinc production, is one of the most toxic elements to which man can be exposed at work or in the environment. Once absorbed, Cd is efficiently retained in the human body, in which it accumulates throughout life. Cd is primarily toxic to the kidney, especially to theproximal tubular cells, the main site of accumulation. Cadmium accumulates in the kidneys and may sometimes cause kidney failure when it is in excess.

Q4. Fruits of this plant are found underground :

(a) Potato (b) Carrot
(c) Groundnut (d) Onion
Ans: (c) The peanuts, or groundnut (Arachishypogaea), is a species in the legume “bean” family (Fabaceae). The cultivated peanut was probably first domesticated in the valleys of Peru. It is an annual herbaceous plant growing tall.

Q5. A rare and endangered animal in Silent Valley is :

(a) Musk deer
(b) Tiger
(c) Lion-tailed macaque
(d) Rhinosores
Ans: (c) Among the more significant inhabitants of the silent valley forests are the lion tailed macaque which is on list of endangered animal and the Silent Valley is one of their habitats on earth. The lion- tailed macaque is one of the most endangered primates of India, confined in distribution to the rainforests of southern Western Ghats. Habitat specialists, they have adapted themselves to the evergreen environments available in the south Indian states of Kerala, Karnataka and Tamil Nadu, It has recently been estimated that only 3,000 to 4,000 individuals survive in the wild

Q6. Quantity of fresh air required for a man is

(a) 1000 cubic feet of air for every 20 minutes
(b) 1000 cubic feet of air for every 20 seconds
(c) 1000 cubic feet of air for every 10 minutes
(d) 1000 cubic feet of air for every 10 seconds
Ans: (a) Breathing sixteen times every minute an average volume of air amounting to 30 cubic inches, we find that the expired air amounts to no less than 17 cubic feet per hour. This contaminated air contains only 16 per cent of oxygen, and 4.5 per cent of carbonic acid gas, and is sufficient to vitiate no less than 3,000 cubic feet of fresh air. Pure fresh air contains from 0.03 to 0.04 per cent of carbonic acid gas, or at the most, .4 volumes per thousand volumes of air. Careful investigation shows that when further carbonic acid gas has been added raising the amount to more than .6 volumes per 1000 of fresh air that an unpleasant odour rapidly becomes perceptible and the air gets to be “close,” musty, or foul. According to these figures a person in a room ten feet square by ten feet high containing a 1000 cubic feet of air requires to have this air completely replaced twice during the hour so as to furnish 3,000 cubic feet of fresh air hourly in order to prevent the carbonic acid gas exceeding .06 per cent.

Q7. Reserpine is used to :

(a) reduce high blood pressure
(b) increase blood pressure when it is low
(c) alleviate pain
(d) cure arthritis
Ans: (a) Reserpine (Lannett’s Serpalan) is an indole alkaloid antipsychotic and antihypertensive drug that has been used for the control of high blood pressure. The antihypertensive actions of reserpine are a result of its ability to deplete catecholamines (among other monoamine neurotransmitters) from peripheral sympathetic nerve endings. These substances are normally involved in controlling heart rate, force of cardiac contraction and peripheral resistance.

Q8. ‘ELISA’ test is employed to diagnose :

(a) Polio virus
(b) AIDS antibodies
(c) Tuberculosis bacterium
(d) Cancer
Ans: (c) ELISA is an abbreviation for “enzyme-linked immuno-sorbent assay.” An ELISA test uses components of the immune system and chemicals to detect immune responses in the body (for example, to infectious microbes).It is used to detect the retrovirus antibodies. The ELISA test involves an enzyme (a protein that catalyzes a biochemical reaction). It also involves an antibody or antigen (immunologic molecules).

Q9. Why excessive heating and repeated use of cooking oil is most undesirable?

(a) The oil vapours can cause indoor pollution
(b) Carcinogenic substances like benzpyrene are produced
(c) Nutrient value of food is lost
(d) Loss and wastage of oil
Ans: (b) Heating an oil changes its characteristics and this means that oils regarded as being healthy at room temperature can become unhealthy when heated above certain temperatures. The smoking point is the temperature at which a particular fat or oil starts to smoke and break down creating acreolein, an obnoxious-smelling compound. A 2001 review found that polyunsaturated oils like soya, canola, sunflower, and corn oil degrade quickly to yield toxic compounds when heated and that prolonged consumption of these degraded polyunsaturated oils was linked to atherosclerosis, inflammatory joint disease and the development of birth defects.

Q10. Which one of the following is a female sex hormone?

(a) Estrogen (b) Androgen
(c) Oxytocin (d) Insulin
Ans: (a) Estrogen is the general name for a group of hormone compounds. It is the main sex hormone in women and is essential to the menstrual cycle. Although both men and women have this hormone, it is found in higher amounts in women, especially those capable of reproducing. Secondary sex characteristics, which are the defining differences between men and women that don’t relate to the reproductive system, are determined in part by estrogen.

Q11. Clove, the commonly used spice, is obtained from the :

(a) root (b) stem
(c) flower bud (d) fruit
Ans: (c) Cloves are the aromatic dried flower buds of a tree in the family Myrtaceae. The clove tree is an evergreen that grows to a height ranging from 8–12 m, having large leaves and sanguine flowers in numerous groups of terminal clusters. The flower buds are at first of a pale colour and gradually become green, after which they develop into a bright red, when they are ready for collecting.

Q12. Labourers who do hard manual labour develop thick skin on their palms and soles due to :

(a) thick epidermis
(b) thick dermis
(c) thick subcutaneous tissue
(d) All of these
Ans: (d) If we look at the dermis, the layer on the skin beneath the epidermis (outer layer), and a certain type of cell within this layer, called a fibroblast, we find that the fibroblasts in the soles and palms secrete higher levels of a protein known as dickkopf 1, or DKK1, than the fibroblasts in the dermis at other body sites. It is believed that the rich source of DKK1 in these areas affects the epidermal layer above it and creates the physical characteristics of thickened, paler skin. DKK1 thickens the epidermis by increasing the number of skin cells and their density. Three genes affected by DKK1 – keratin 9, áKLEIP and â-catenin – have been found to cause this thickening. Keratin 9 reinforces the skin against physical impact, áKLEIP aids in cell division (multiplying) and makes cells smaller and, finally, a reduction in â-catenin is also possibly involved in cell contraction (making the cells more compact).

Q13. Maximum photosynthetic activity occurs in :

(a) blue and red region of light
(b) green and yellow region of light
(c) blue and orange region of light
(d) violet and orange region of light
Ans: (a) Wavelength of light between 400 nm and 700 nm is most effective for photosynthesis. This light is called photosynthetically active radiation (PAR). Comparatively more photosynthesis occurs is red and blue regions though others have significant net photosynthesis. Light has maximum efficiency in red and minimum in blue region. In both these regions light is absorbed by chlorophylls. Red light favours more carbohydrate accumulation while blue light favours more protein synthesis.

Q14. AIDS virus has :

(a) single-stranded RNA
(b) double-stranded RNA
(c) single-stranded DNA
(d) double-stranded DNA
Ans: (a) AIDS viruses have single stranded RNA. It is composed of two copies of positive single-stranded RNA that codes for the virus’s nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein. The single-stranded RNA is tightly bound to nucleocapsid proteins.

Q15. A ‘breath test’ used by traffic police to check drunken driving uses:

(a) potassium dichromate-sulphuric acid
(b) potassium perma-nganatesulphuric acid
(c) turmeric on filter paper
(d) silica gel coated with silver nitrate
Ans: (a) The main constituent of alcohol is Ethanol and the concentration of ethanol in a sample can be determined by back titration with acidified potassium dichromate. Reacting the sample with an excess of potassium dichromate, all ethanol is oxidized to acetic acid. One major application for this reaction is in old police breathalyzer tests. When alcohol vapor makes contact with the yellow dichromate-coated crystals, the color changes from yellow to green. The degree of the color change is directly related to the level of alcohol in the suspect’s breath.

Q16. Anglo-Nubian is a breed of :

(a) sheep (b) goat
(c) poultry (d) cattle
Ans: (b) The Anglo-Nubian, or simply Nubian in the United States, is a breed of domestic goat. The breed was developed in Great Britain of native milking stock and goats from the Middle East and North Africa. Its distinguishing characteristics include large, pendulous ears and a “Roman” nose. Due to their Middle-Eastern heritage, Anglo-Nubians can live in very hot climates and have a longer breeding season than other dairy goats. Considered a dairy or dual-purpose breed, Anglo-Nubians are known for the high butterfat content of their milk, although on average, the breed produces less milk than other dairy breeds.

Q17. What kind of soil is treated with gypsum to make it suitable for cropping?

(a) Alkaline
(b) Acidic
(c) Water-logged
(d) Soil with excessive clay content
Ans: (a) Alkaline soils are treated with gypsum to make it suitable for cropping. Alkaline soils are clay soils with high pH (> 9), a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth. Alkali soils owe their unfavorable physico-chemical properties mainly to the dominating presence of sodium carbonate which causes the soil to swell and difficult to settle. Gypsum (calcium sulphate, CaSO4. 2H2O) can also be applied as a source of Ca++ ions to replace the sodium at the exchange complex. There must be enough natural drainage to the underground, or else an artificial subsurface drainage system must be present, to permit leaching of the excess sodium by percolation of rain and/or irrigation water through the soil profile.

Q18. Typhoid fever is caused by-

(a) virus (b) bacteria
(c) fungus (d) allergy
Ans: (b) Typhoid fever, also known as typhoid, is a common worldwide bacterial disease, transmitted by the ingestion of food or water contaminated with the feces of an infected person, which contain the bacterium Salmonella typhi, serotype Typhi.

Q19. Which of the following blood group is a universal reciptient?

(a) A (b) B
(c) AB (d) O
Ans: (c) Blood group AB individuals have both A and B antigens on the surface of their RBCs, and their blood plasma does not contain any antibodies against either A or B antigen. Therefore, an individual with type AB blood can receive blood from any group (with AB being preferable), but cannot donate blood to either A or B group. They are known as universal recipients.

Q20. Rod shaped bacteria is called

(a) Bacillus (b) Spirillum
(c) Coccus (d) Coma
Ans: (a) Bacillus is a genus of Gram-positive, rod-shaped bacteria and a member of the phylum Firmicutes. Bacillus species can be obligate aerobes or facultative anaerobes, and test positive for the enzyme catalase. Bacillus includes both free-living and pathogenic species. Under stressful environmental conditions, the cells produce oval endospores that can stay dormant for extended periods.

Q21. The animal which has become extinct recently in India happens to be

(a) Golden cat (b) Cheetah
(c) Wooly wolf (d) Rhinoceros
Ans: (b) Cheetahs have been known to exist in India for a very long time, but as a result of hunting and other causes, cheetahs have been extinct in India since the 1940s.The cheetah is the only animal that has been described extinct in India in the last 100 years.

Q22. All the progeny obtained from a single plant by vegetative propagation are called

(a) Clones (b) Pure line
(c) Indred line (d) Pedigree line
Ans: (a) A clone is obtained by vegetative propagation of a single plant and it propagates vegetatively in successive generation. It offers excitation for exploiting desirable mutations. It maintains purity of race in heterozygous state. The clones retains their original characteristics after many years of vegetative propagation i.e. they are stable.

Q23. What is a Sponge ?

(a) A fungus (b) A fossil
(c) A plant (d) An animal
Ans: (d) Sponges are animals of the phylum Porifera. They are multicellular organisms which have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and which often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems.

Q24. Which of the following blood groups may be present in the children of a couple having blood groups A and B, respectively?

(a) A and B only
(b) A, B and AB
(c) A, B, AB and O
(d) AB only
Ans: (c) A heterozygous woman with type A blood and a heterozygous man with type B blood have, as you figured with your Punnet square, a 25% chance with each child that the child will have blood group O, 25% chance for blood group A, 25% chance for blood group B, and 25% chance for blood group AB. The same is true for the reciprocal cross: a heterozygous woman with type B blood and a heterozygous man with type A blood. In such a family, the existence of a child with blood group O is evidence that both parents are heterozygous.

Q25. Which of the following diseases is caused by a virus?

(a) Polimyletis
(b) Malaria
(c) Whooping cough
(d) Ring worm
Ans: (a) Poliomyelitis, often called polio or infantile paralysis, is an acute, viral, infectious disease spread from person to person, primarily via the fecal-oral route. The term derives from the Greek poliós, meaning “grey”, myelós, referring to the grey matter of the spinal cord, and the suffix -itis, which denotes inflammation., i.e., inflammation of the spinal cord’s grey matter, although a severe infection can extend into the brainstem and even higher structures, resulting in polioencephalitis, producing apnea that requires mechanical assistance such as an iron lung.

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