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UPSC > Applied Science

Explore popular questions from Applied Science for UPSC. This collection covers Applied Science previous year UPSC questions hand picked by experienced teachers.

Q 1.

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Living organisms require at least 27 elements, of which 15 are metals. Among these, those required in major quantities, include

A

potassium, manganese, molybdenum and calcium

B

potassium, molybdenum, copper and calcium

potassium, sodium, magnesium and calcium

D

sodium, magnesium, copper and manganese

Explanation

Living organism require about 27 elements of which 15 are metals. K, Mg, Na and Ca are required in major quantities. Minor quantity of Mn, Fe, Co, Cu, Zn and Mo and trace amount of V, Cr, Sn, Ni and Al are required by some organisms.
Calcium, magnesium and phosphorus are essential parts of the bones and teeth.
Calcium is necessary for blood clotting.
Sodium helps in muscle activity and transmission of nerve.

Q 2.

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Which one of the following organisms can serve as a biofertilizer for rice crop?

Blue-green algae

B

Rhizobium sp.

C

Mycorrhizal fungi

D

Azotobacter sp.

Explanation

Blue green algae is used as a biofertilizer in rice crop. Blue green algae has the nitrogen fixing ability which enhances the production of rice.

Q 3.

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Which one of the following is monogamous?

A

Wolf

B

Walrus

C

Seal

Deer

Explanation

Deer is monogamous. Monogamous is the organism which has only one spouse and mate at any one time.

Q 4.

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Which one of the following parts of the pitcher plant becomes modified into a pitcher?

A

Stem

Leaf

C

Stipule

D

Petiole

Explanation

In pitcher plant, the lamina of leaf is modified into pitcher and the leaf apex gives rise to a coloured lid for attracting the insects.

Q 5.

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Consider the following statements:
1. Sweet orange plant is propagated by grafting technique.
2. Jasmine plant is propagated by layering technique.
Which of the statements given above is/are correct?

A

1 only

B

2 only

Both 1 and 2

D

Neither 1 nor 2

Explanation

Grafting is a most common method of vegetative propagation. In this method, parts of two plants are joined in such a way that they grow as a one plant. Sweet orange plant is propagated by grafting technique. Layering is another type of vegetative propagation. In this method, roots are artificially induced on the stem branches before they are detached from the plant for propagation. Jasmine plant is propagated by this technique.

Q 6.

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Other than resistance to pests, what are the prospects for which genetically engineered plants have been created?
1. To enable them to withstand drought
2. To increase the nutritive value of the produce
3. To enable them to grow and do photosynthesis in spaceships and space stations
4. To increase their shelf life
Select the correct answer using the codes given below :

A

1 and 2 only

B

3 and 4 only

1, 2 and 4 only

D

1, 2, 3 and 4

Explanation

Except 3rd, all the statements are correct.

Q 7.

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Which of the following leaf modifications occurs/occur in desert areas to inhibit water loss?
1. Hard and waxy leaves
2. Tiny leaves or no leaves
3. Thorns instead of leaves
Select the correct answer using the codes given below.

A

1 and 2 only

B

2 only

C

1 and 3 only

1, 2 and 3

Explanation

To inhibit water loss or to conserve water most of the desert species have waxy leaves that keep them water proof when stomata are closed. Water is further conserved by reducing surface area so most succulents have few leaves or no leaves. Some desert plants have thorns instead of leaves. Thorns do not let the water go out.

Q 8.

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A person with 'AB' blood group is sometimes called a universal recipient because of the

A

lack of antigen in his blood

lack of antibodies in his blood

C

lack of both antigens and antibodies in his blood

D

presence of antibodies in his blood

Explanation

Person having blood group 'AB' is called universal recepient because the 'AB' blood group has no antibody in the blood plasma. So, the person can accept any type of blood group (i.e. A, B and O)

Q 9.

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Which one of the following is a membrane that protects the developing embryo from desiccation?

Amnion

B

Allantois

C

Chorion

D

Yolk sac

Explanation

The amnion is a membrane that protects the developing embryo by a fluid-filled space called amniotic cavity. Amnion is formed above the embryo.

Q 10.

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Of the four landmarks in medical history given below, which one was the first to take place ?

A

Organ transplant

B

Bypass surgery

C

Test tube baby

Plastic surgery

Explanation

Invention - Year - Scientist
Organ transplant - 1959 - Josep E. Murray
Bypass surgery - 1960 - Albert Einstein
Test tube baby - 1978 - Louis Joy Brown
Plastic surgery -1827- Dr. John peter Mettauer

Q 11.

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Which of the following are associated with Diabetes mellitus, a common disease in adults ?
1. Higher sugar level in blood
2. Lower sugar level in blood
3. Lower insulin level in blood
4. Higher insulin level in blood
Select the correct answer by using the codes given below:
Codes:

A

2 and 4

B

1 and 2

C

2 and 3

1 and 3

Explanation

Diabetes mellitus is caused due to deficiency of insulin hormone. The hormone insulin maintains the blood sugar in body. Deficiency of insulin in human body causes increase the sugar level in blood, which leads to Diabetes mellitus.

Q 12.

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Antigen is a substance which

A

lowers body temperatures

B

destroys harmful bacteria

triggers the immune system

D

is used as an antidote to poison

Explanation

Antigen is a foreign molecule that invade the body of an organism. Antigen also induce immune response to stimulate lymphocyte to produce antibody. The majority of them are proteins and polysaccharides found on the wall of bacteria and on the cell coats of virus.

Q 13.

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Which one of the following type of micro organisms is most widely used in industries?

A

Bacteria

B

Bacteria and fungi

C

Bacteria and algae

Bacteria, microalgae and fungi

Explanation

Bacteria, microalgae and fungi is most widely used in industries. Bacteria like Lactobacillus sp. is used in manufacturing of vinegar and alcohol by fementation process.
Most of algae are used as single cell protein (i.e. Spirulina).
Different drugs like penicillin is manufactured from fungi Penicillium notatum.

Q 14.

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Match List-I with List-II and select the correct answer using the codes given below the lists:

List-IList-II
A. Theory of mutation1. Beadle and Tatum
B. Theory of evolution2. Jacob and Monad
C. One gene one enzyme hypothesis3. Darwin
D. Operon concept4. de Vries

Codes :

A

A - 3; B - 4; C - 1; D - 2

A - 4; B - 3; C - 1; D - 2

C

A - 4; B - 3; C - 2; D - 1

D

A - 3; B - 4; C - 2; D - 1

Explanation

Theory of mutation is postulated by de Vries. Theory of evolution is by Charl's Darwin. Operon concept is given by Jacob and Monad. One gene and one enzyme hyoptheisis is proposed by Beadle and Tautum.

Q 15.

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A tree species in Mauritius failed to reproduce because of the extinction of a fruit-eating bird. Which one of the following was that bird?

A

Dove

Dodo

C

Condor

D

Skua

Explanation

Dodo birds species existed only on the island of Mauritius. Due to its short wings and bulky body the Dodo birds could not fly or flee in the face of danger. So human used to kill them for food. Later the species became extinct from Mauritius. This bird species was helpful in pollinating and propagating seed of trees.

Q 16.

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The complete conversion of glucose, in the presence of oxygen, into carbon dioxide and water with release of energy is called

aerobic respiration

B

anaerobic respiration

C

glycolysis

D

hydrolysis

Explanation

The complete conversion of glucose in presence of oxygen, into carbon dioxide, water and release energy is called aerobic respiration. Anaerobic respiration, occurs in the absence of oxygen.

Q 17.

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Consumption of fish is considered to be healthy when compared to flesh of other animals because fish contains

polyunsaturated fatty acids

B

saturated fatty acids

C

essential vitamins

D

more carbohydrates and proteins

Explanation

Polyunsaturated fatty acid is an anti oxidant, which helps in building of tissues.

Q 18.

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Match List-I with List-II and select the answer using the codes given below:

List-I (Disease)List-II (Organism)
A. Malaria1. Fungi
B. Poliomyelitis2. Bacteria
C. Tuberculosis3. Virus
D. Ringworm4. Protozoan

A-4; B-3; C-2; D-1

B

A-4; B-3; C-1; D-2

C

A-3; B-4; C-1; D-2

D

A-3; B-4; C-2; D-1

Explanation

Malaria parasite is an protozoan. Tuberculosis is a bacteria. Ring worm is a fungus and Poliomyelitis is a virus.

Q 19.

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Haemophilia is a genetic disorder which leads to

A

decrease in haemoglobin level

B

rheumatic heart disease

C

decrease in WBC

non-clotting of blood

Explanation

Haemophilia is a sex-linked recessive disorder. Clotting of blood is abnormally delayed that even a simple or small cut will result non stop bleeding in affected individual.

Q 20.

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Endoscopy, a technique used to explore the stomach or other inner parts of the body is based on the phenomenon of

total internal reflection

B

interference

C

diffraction

D

polarization

Explanation

Endoscopy refers to looking inside the body through endoscope. Endoscope is an instrument used to examine interior of hollow organ of the body through bore scope technique.

Q 21.

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When ants bite, they inject

A

glacial acetic acid

B

methanol

formic acid

D

stearic acid

Explanation

When ants bite, they inject formic acid in the muscle tissue. This formic acid is found at the mandible of ants.

Q 22.

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In eye donation, which one of the following parts of donor's eye is utilized?

A

Iris

B

Lens

Cornea

D

Retina

Explanation

Generally blindness is caused by the dryness and hardness of cornea. Cornea is a clear layer which helps passing of light. It is an outer layer and can be transfer from one person to another.

Q 23.

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Match the hormones in List-I with items in List-II and
Select the correct answer using the codes given below:

List- IList-II
A. Adrenaline1. Anger, fear, danger
B. Estrogen2. Attracting partners through sense of smell
C. Insulin3. Females
D. Pheromones4. Glucose

A

A - 3; B - 1; C - 4; D - 2

B

A - 1; B - 3; C - 2; D - 4

A - 1; B - 3; C - 4; D - 2

D

A - 3; B - 1; C - 2; D - 4

Explanation

Adrenaline is the hormone prepares the body to deal with anger, fear and danger.
Estrogen hormone releases from ovary of female. Insulin controls the level of glucagon in blood.
Pheromones attracts partners through sense of smell.

Q 24.

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Match List-I (Drugs/Chemicals) with List -II (Their uses) and select the correct answer using the codes given below

List-IList-II
A. Atropine1. Local anaesthesia
B. Ether2. Heart trouble
C. Nitroglycerine3. Dilation of pupil
D. Pyrethrin4. Mosquito control

Codes :

A

A - 1; B - 3; C - 2; D - 4

B

A - 1; B - 3; C - 4; D - 2

C

A - 3; B - 1; C - 4; D - 2

A - 3; B - 1; C - 2; D - 4

Explanation

Ether is used as an anesthesia at the time of surgery to prevent pain. Atropine is used as eye drops to dilate the pupil before eye examination. Nitroglycerine is widely used in the treatment of heart. Pyrethrin is biodegradable, non-persistent pesticide which is used to kill mosquitoes, fleas and other insects.

Q 25.

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Assertion (A) : In human being, the females play a major role in determining the sex of the offspring.
Reason (R) : Women have two 'X' chromosomes.

A

Both A and R are true and R is the correct explanation of A

B

Both A and R are true but R is not a correct explanation of A

C

A is true but R is false

A is false but R is true

Explanation

Assertion is false. In human, sex determination of offspring depends on male because male sperm contains XY chromosome, whereas female has XX chromosome in their ovum.