106 previous year UPSC Prelims questions on the UPSC 1998 Prelims. Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 91–100 of 106 questions
Browse by subject
UPSC 1998Science and Technology · Biology: Botany
Q91. Ergotism is due to consumption of:
Explanation
Ergotism is historically known as "St. Anthony’s Fire" is directly linked to the consumption of grains (such as rye, barley, wheat, and oats) contaminated with the ergot fungus (Claviceps purpurea). The fungus infects the grains, producing sclerotia (ergot bodies) that contain toxic alkaloids. These alkaloids can cause two forms of ergotism:
Convulsive ergotism which is cracterized by seizures, hallucinations, and muscle spasms. Gangrenous ergotism which leads to restricted blood flow, causing tissue death and gangrene in extremities.
UPSC 1998Science and Technology · Biology: Botany
Q92. Which one of the following types of micro organisms is most widely used in industries?
Explanation
In industrial applications, a wide range of microorganisms are used due to their ability to carry out various biochemical processes that are beneficial for different industries. The following microorganisms are widely used:
Bacteria is used in industries such as fermentation, bioremediation, and food production (e.g., yogurt, cheese, and antibiotics). Microalgae is used in the production of biofuels, aquaculture feed, and nutraceuticals. They are also involved in carbon sequestration. Fungi is widely used in the pharmaceutical industry for the production of antibiotics (such as penicillin) and enzymes. They are also used in fermentation and the production of organic acids.
UPSC 1998Science and Technology · Biology: Botany
Q93. Match List-I with List-II and select the correct answer by using the codes given below the lists
List-I
List-II
A. Fruit
1. Ovule
B. Seed
2. Leaf
C. Wood
3. Stem
D. Starch
4. Ovary
Explanation
A is matched with 4: Fruit develops from the ovary of the flower after fertilization. The ovary, which contains the ovules, transforms into the fruit as the seeds inside mature. This process is an essential part of the plant’s reproductive cycle. B is matched with 1: Seed originates from the ovule after fertilization. The ovule, located inside the ovary, contains the female gamete (egg cell). Once fertilized by the male gamete (pollen), the ovule develops into a seed, which contains the embryo and stored food for the new plant. C is matched with 3: Wood is produced from the stem of the plant. The stem, with its vascular tissues (xylem and phloem), supports the plant and transports nutrients. The xylem, which is a type of vascular tissue, forms the wood, providing structural support and helping in water transport. D is matched with 2: Starch is primarily produced in the leaf. During photosynthesis leaves use sunlight, water, and carbon dioxide to produce glucose. Some of this glucose is converted into starch, a storage form of sugar, and is stored in the chloroplasts of the leaf.
UPSC 1998Science and Technology · Biology: Botany
Q94. Which one of the following statements regarding starch and cellulose is not correct?
Explanation
Statement (a) is correct: Starch and cellulose are both found in plants. Starch serves as an energy reserve and cellulose is a structural component of plant cell walls. Statement (b) is correct: Both starch and cellulose are polymers made up of repeating units (monomers) of glucose. Starch and cellulose are polysaccharides Statement (c) is incorrect: While starch gives a blue-black color with iodine, cellulose does not give any significant color reaction with iodine under normal conditions. Starch is a polysaccharide composed of glucose units and gives a blue-black color when iodine is added, which is a characteristic test for starch. Starch occurs in plants in the form of granules, and these are particularly abundant in seeds (especially the cereal grains) and tubers, where they serve as a storage form of carbohydrates. The Cellulose, a fibrous carbohydrate found in all plants, is the structural component of plant cell walls. Cellulose is also a polymer of glucose but its structure differs from starch. Cellulose does not form the characteristic blue-black color with iodine due to the difference in the way glucose molecules are linked in cellulose. Statement (d) is correct: Both starch and cellulose are made up of glucose molecules, but in different forms. Starch consists of alpha-glucose while cellulose consists of beta-glucose.
UPSC 1998General Knowledge · Contemporary Events: India
Q95. Bharat Ratna was awarded in 1997 to:
Explanation
An aerospace and defence scientist, Kalam was involved in the development of India’s first satellite launch vehicle SLV III and was the architect of the Integrated Guided Missile Development Program. He also served as the eleventh President of India from 2002 till 2007. Dr. A.P.J. Abdul Kalam was awarded the Bharat Ratna in 1997 for his contributions to science and defense technology.
UPSC 1998General Knowledge · Contemporary Events: India
Q96. Which of the following Parties were not a part of the United Front Which was in power during ‘96-97’? 1. Bahujana Samaj Party 2. Haryana Vikas Party 3. Samata Party 4. Asom Gana Parishad Select the correct answer using the codes given below: Codes:
Explanation
The United Front was a coalition of political parties that was in power from 1996 to 1997. The major parties that were part of the United Front included the Samajwadi Party, the CPI (M), the Indian National Congress (which provided support), Asom Gana Parishad (AGP) and smaller regional parties. Hence among the options, Bahujan Samaj Party, Haryana Vikas Party and Samata Party were not part of United Front.
UPSC 1998General Knowledge · Contemporary Events: India
Q97. The damage to the Spektr Module of the Russian Space Station Mir was due to:
Explanation
The damage to the Spektr Module of the Russian Space Station Mir occurred due to a collision with a Soyuz cargo ship in 1997 during a routine docking maneuver. The collision caused a significant breach in the module, leading to a loss of oxygen and other technical issues.
UPSC 1998General Knowledge · Contemporary Events: India
Q98. Which one of the following was the venue for the preliminary talks between the Sri Lankan Government and representatives of Tamil United Liberation Front and other militant groups?
Explanation
The venue for the preliminary talks between the Sri Lankan Government and representatives of the Tamil United Liberation Front (TULF) and other militant groups was Thimphu, the capital of Bhutan. These talks took place in 1985 and were an attempt to resolve the ongoing ethnic conflict between the Tamil population and the Sri Lankan government.
UPSC 1998Geography · Places and Locations: World Geography
Q99. When there is noon at I.S.T. meridian people at another place of the earth are taking their 6 O’ clock morning tea. The longitude of the place is:
Explanation
Option (b) is correct: Indian Standard Time (I.S.T.) is based on the meridian 82°30’ E, which is the reference for I.S.T. If it is noon (12:00 PM) at I.S.T., and people at another place are having 6:00 AM morning tea, that means the time difference between the two places is 6 hours. To calculate the longitude difference:
A time difference of 1 hour corresponds to a 15° difference in longitude. Therefore, a 6-hour difference corresponds to a 90° difference in longitude (6 × 15°). Since the other place is 6 hours behind I.S.T., it must be 90° to the west of the I.S.T. meridian. I.S.T. The meridian is at 82°30’ E, so moving 90° to the west brings us to 7°30’ W. Thus, the place is at a longitude of 7°30’ W.
UPSC 1998Science and Technology · Biology: Zoology
Q100. Match List-I with List-II and select the correct answer using the codes given below the lists:
List-I
List-II
A. Theory of mutation
1. Beadle and Tatum
B. Theory of evolution
2. Jacob and Monad
C. One gene one enzyme
3. Darwin hypothesis
D. Operon concept
4. de Vries
Explanation
A is matched with 4: Hugo de Vries proposed the Mutation Theory in the early 20th century which suggested that new species arise through sudden, discontinuous changes (mutations) in genetic material. B is matched with 3: Darwin>s Theory of Evolution was published in 1859 (On the Origin of Species). It explains evolution through natural selection and gave key concepts include adaptive radiation, survival of the fittest, and descent with modification. C is matched with 1: George Beadle and Edward Tatum proposed the One Gene One Enzyme Hypothesis, which states that each gene is responsible for producing a single enzyme that controls a specific biochemical reaction. D is matched with 2: Jacob and Monod>s Operon Concept was introduced in 1961 which explains how gene regulation in prokaryotes (e.g., lac operon in E. coli). It is key for understanding antibiotic resistance and gene expression.
Answer key for these questions
Q
UPSC year
Correct answer
91
1998
(a) contaminated grains
92
1998
(d) Bacteria, microalgae and fungi
93
1998
(b) A-4; B-1; C-3; D-2
94
1998
(c) Both of them give colour with iodine
95
1998
(d) Dr. Abdul Kalam
96
1998
(b) 1, 2 and 3
97
1998
(a) collision with a Soyuz cargo ship
98
1998
(c) Thimpu
99
1998
(b) 7°30’ W.
100
1998
(b) A - 4; B - 3; C - 1; D - 2
Frequently asked questions
How many previous year UPSC questions are there on all subjects?
This page covers 106 previous year UPSC Prelims GS Paper-I questions on the UPSC 1998 Prelims, asked from 1995 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for all subjects?
Questions on the UPSC 1998 Prelims are available for 31 years, from 1995 to 2025. Use the Year filter to practise a single paper.