Q: Which one of the following is synthesised in human body that dilates blood vessels and increases blood flow?
(a)Nitric oxide
(b)Nitrous oxide
(c)Nitrogen dioxide
(d)Nitrogen pentoxide
Loading...
Biology — UPSC Prelims Previous Year Questions
96 questions from UPSC CSE Prelims GS Paper 1 on Biology (Science & Technology). Spanning from 1995 to 2024. Practice with show/hide answers and detailed explanations.
96
Questions
24
Years
69
Easy
27
Moderate
Year-wise Distribution
What UPSC Asks About Biology
Based on 96 questions across 24 years, UPSC has consistently tested aspirants' understanding of Biology within the broader Science & Technology syllabus. The questions range from factual recall to application-based analysis.
Recent trends show UPSC moving towards statement-based questions that combine multiple aspects of Biology. Aspirants should focus on understanding concepts rather than memorizing isolated facts.
Related Science & Technology Sub-topics
All Biology Questions
Q: Which one of the following statements best describes the role of B cells and T cells in the human body?
(a)They protect the body from environmental allergens.
(b)They alleviate the body's pain and inflammation.
(c)They act as immunosuppressants in the body.
(d)They protect the body from the diseases caused by pathogens.
Q: Which of the following have species that can establish symbiotic relationship with other organisms? 1. Cnidarians 2. Fungi 3. Protozoa Select the correct answer using the code given below:
(a)1 and 2 only
(b)2 and 3 only
(c)1 and 3 only
(d)1, 2 and 3
Q: निम्नलिखित कथनों में से कौन-से पादप और प्राणी कोशिकाओं के बीच सामान्य अंतर के बारे में सही हैं ? 1. पादप कोशिकाओं में सेलुलोज कोशिका भित्तियाँ होती हैं जबकि प्राणी कोशिकाओं में वे नहीं होतीं । 2. पादप कोशिकाओं में प्लाज्मा झिल्ली नहीं होती जबकि इसके विपरीत प्राणी कोशिकाओं में वे होती हैं । 3. परिपक्व पादप कोशिका में एक बृहद रसधानी होती है जबकि प्राणी कोशिका में अनेक छोटी रसधानियाँ होती हैं । नीचे दिए गए कूट का प्रयोग कर सही उत्तर चुनिए :
(a)केवल 1 और 2
(b)केवल 2 और 3
(c)केवल 1 और 3
(d)1, 2 और 3
Q: शब्द ‘डेनिसोवन (Denisovan)’ कभी-कभी समाचार माध्यमों में किस संदर्भ में आता है?
(a)एक प्रकार के डायनासोर का जीवाश्म
(b)एक आदिम मानव जाति (होमिनिन)
(c)पूर्वोत्तर भारत में पाया गया एक गुफा-तंत्र
(d)भारतीय उपमहाद्वीप के इतिहास में एक प्रसिद्ध पुरातात्त्विक स्थल
Q: Which of the following phenomena might have influenced the evolution of organisms? 1. Continental drift 2. Glacial cycles Select the correct answer using the code given below.
(a)1 only
(b)2 only
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: Consider the following : 1. Bats 2. Bears 3. Rodents The phenomenon of hibernation can be observed in which of the above kinds of animals?
(a)1 and 2 only
(b)2 only
(c)1, 2 and 3
(d)Hibernation cannot be observed in any of the above
Q: Lichens, which are capable of initiating ecological succession even on a bare rock, are actually a symbiotic association of
(a)algae and bacteria
(b)algae and fungi
(c)bacteria and fungi
(d)fungi and mosses
Q: Which one of the following is the process involved in photosynthesis?
(a)Potential energy is released to form free energy
(b)Free energy is converted into potential energy and stored
(c)Food is oxidized to release carbon dioxide and water
(d)Oxygen is taken in, and carbon dioxide and water vapour are given out
Q: Consider the following statements : 1. Maize can be used for the production of starch. 2. Oil extracted from maize can be a feedstock for biodiesel. 3. Alcoholic beverages can be produced by using maize. Which of the statements given above is/are correct?
(a)1 only
(b)1 and 2 only
(c)2 and 3 only
(d)1, 2 and 3
Q: Among the following organisms, which one does not belong to the class of other three?
(a)Crab
(b)Mite
(c)Scorpion
(d)Spider
Q: Consider the following minerals: 1. Calcium 2. Iron 3. Sodium Which of the minerals given above is/are required by human body for the contraction of muscles?
(a)1 only
(b)2 and 3 only
(c)1 and 3 only
(d)1, 2 and 3
Q: Fruits stored in a cold chamber exhibit longer storage life because
(a)exposure to sunlight is prevented
(b)concentration of carbon dioxide in the environment is increased
(c)rate of respiration is decreased
(d)there is an increase in humidity
Q: Many transplanted seedlings do not grow because
(a)the new soil does not contain favourable minerals
(b)most of the root hairs grip the new soil too hard
(c)most of the root hairs are lost during transplantation
(d)leaves get damaged during transplantation
Q: When the bark of a tree is removed in a circular fashion all around near its base, it gradually dries up and dies because
(a)Water from soil cannot rise to aerial parts
(b)Roots are starved of energy
(c)Tree is infected by soil microbes
(d)Roots do not receive oxygen for respiration
Q: Which one of the following processes in the bodies of living organisms is a digestive process ?
(a)Breakdown of proteins into amino acids
(b)Breakdown of glucose into CO₂ and H₂O
(c)Conversion of glucose into glycogen
(d)Conversion of amino acids into proteins
Q: From the point of view of evolution of living organisms, which one of the following is the correct sequence of evolution ?
(a)Otter – Tortoise – Shark
(b)Shark – Tortoise – Otter
(c)Tortoise – Shark – Otter
(d)Shark – Otter – Tortoise
Q: 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
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: Consider the following : 1. Camphor 2. Chicory 3. Vanilla Which of the above is/are plant product(s) ?
(a)1 and 2 only
(b)3 only
(c)1 and 3 only
(d)1, 2 and 3
Q: In the context of Indian wild life, the flying fox is a
(a)Bat
(b)Kite
(c)Stork
(d)Vulture
Q: In making the saffron spice, which one of the following parts of the plant is used ?
(a)Leaf
(b)Petal
(c)Sepal
(d)Stigma
Q: With reference to the evolution of living organisms, which one of the following sequences is correct?
(a)Octopus – Dolphin – Shark
(b)Pangolin – Tortoise – Hawk
(c)Salamander – Python – Kangaroo
(d)Frog – Crab – Prawn
Q: In which one of the following kinds of organisms is the phenomenon found wherein the female kills the male after copulation?
(a)Dragonfly
(b)Honeybee
(c)Spider
(d)Pit viper
Q: Which one of the following is an insectivorous plant?
(a)Passion flower plant
(b)Pitcher plant
(c)Night queen
(d)Flame of the forest
Q: What is the pH level of blood of a normal person?
(a)4·5 – 4·6
(b)6·45 – 6·55
(c)7·35 – 7·45
(d)8·25 – 8·35
Q: Norman Ernest Borlaug who is regarded as the father of the Green Revolution in India is from which country?
(a)United States of America
(b)Mexico
(c)Australia
(d)New Zealand
Q: Assertion (A): In human body, liver has an important role in fat digestion. Reason (R): Liver produces two important fat-digesting enzymes.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is not the correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: Among the following, which one lays eggs and does not produce young ones directly?
(a)Echidna
(b)Kangaroo
(c)Porcupine
(d)Whale
Q: Which one of the following parts of the pitcher plant becomes modified into a pitcher?
(a)Stem
(b)Leaf
(c)Stipule
(d)Petiole
Q: In the human body, to which structure is the appendix attached?
(a)The large intestine
(b)The small intestine
(c)The gall-bladder
(d)The stomach
Q: In the human body which one of the following hormones regulates blood calcium and phosphate?
(a)Glucagon
(b)Growth hormone
(c)Parathyroid hormone
(d)Thyroxin
Q: How do most insects respire?
(a)Through skin
(b)Through gills
(c)By lungs
(d)By tracheal system
Q: Which one of the following parts of the human brain is the regulating centre for swallowing and vomiting?
(a)Cerebellum
(b)Cerebrum
(c)Medulla oblongata
(d)Pons
Q: Production of which one of the following is a function of the liver?
(a)Lipase
(b)Urea
(c)Mucus
(d)Hydrochloric acid
Q: Which of the following is not a digestive enzyme in the human system?
(a)Trypsin
(b)Gastrin
(c)Ptyalin
(d)Pepsin
Q: Which of the following light types of light are strongly absorbed by plants:
(a)Violet and Orange
(b)Blue and Red
(c)Indigo and Yellow
(d)Yellow and Violet
Q: In human beings, normally in which one of the following parts does the sperm fertilize the ovum?
(a)Cervix
(b)Fallopian Tube
(c)Lower Part of Uterus
(d)Upper Part of Uterus
Q: Which on the following is the correct sequence in order of decreasing length of the three structural parts given below of small intestine in the human body?
(a)Jejunum – Duodenum – Ileum
(b)Ileum – Duodenum – Jejunum
(c)Jejunum – Ileum – Duodenum
(d)Ileum – Jejunum – Duodenum
Q: What is the name of the vessel that delivers the nutrient-rich blood from the stomach and small intestine to the liver?
(a)Left hepatic artery
(b)Hepatic vein
(c)Right hepatic artery
(d)Hepatic portal vein
Q: Consider the following statements with reference to the human body: 1. The common bile duct releases its contents into the stomach. 2. The pancreatic duct releases its contents into the duodenum. Which of the statements given above is/are correct?
(a)1 only
(b)2 only
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: What is the order of magnitude of electric resistance of the human body (dry)?
(a)10² ohm
(b)10⁴ ohm
(c)10⁶ ohm
(d)10⁸ ohm
Q: Consider the following statements : 1. During the process of osmosis, the solvent travels from the concentrated solution to the dilute solution. 2. In the reverse osmosis, external pressure is applied to the dilute solution. Which of the statements given above is/are correct?
(a)1 only
(b)2 only
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: Assertion (A): All the proteins in our food are digested in small intestine only. Reason (R): The protein-digesting enzymes from pancreas are released into small intestine.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is not the correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: Assertion (A): Amoeba reproduces by fission. Reason (R): All unicellular organisms reproduce by asexual methods.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is not the correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: The hormone insulin is a
(a)Glycolipid
(b)Fatty acid
(c)Peptide
(d)Sterol
Q: In which organ of the human body are the lymphocyte cells formed?
(a)Liver
(b)Long bone
(c)Pancreas
(d)Spleen
Q: With reference to the work of human kidney, consider the following statements: 1. After the waste is removed in the kidney, the cleaner blood is sent back through renal artery. 2. From Bowman’s capsule, the filtered liquid passes through tiny tubes where much of the glucose is reabsorbed and sent back to the blood in the renal vein. Which of these statements is/are correct?
(a)Only 1
(b)Only 2
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: Octopus is
(a)an arthropod
(b)an echinoderm
(c)a hemichordate
(d)a mollusc
Q: With reference to normal human beings, consider the following statements: 1. In response to the presence of HCl, secretin is produced from the duodenum 2. Enterogastrone is produced in the small intestine in response to the presence of fatty acids Which of these statements is/are correct?
(a)Only 1
(b)Only 2
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: Among living organisms, which one of the following is the most responsible factor for bringing about the origin of a new species?
(a)Isolation
(b)Mutation
(c)Natural Selection
(d)Sexual Reproduction
Q: Ticks and mites are actually
(a)Arachnids
(b)Crustaceans
(c)Insects
(d)Myriapods
Q: With reference to the blood in a normal person, which one of the following statements is correct?
(a)Compared to arteries, veins are less numerous and hold less of the body’s blood at any given time
(b)Blood cells constitute about 70 % of the total volume of the blood
(c)White Blood Cells (WBC) are made by lymph nodes only
(d)The blood has more platelets than WBC
Q: Consider the following plants: 1. Bougainvillea 2. Carnations 3. Cocoa 4. Grapes Which of these plants are propagated by stem cuttings?
(a)1 and 2
(b)2, 3 and 4
(c)1, 3 and 4
(d)1, 2, 3 and 4
Q: In the context of the organic evolution, the loss of limbs of snakes is explained by the phenomenon of
(a)use and disuse of organs
(b)adaptation to living in burrows
(c)natural selection
(d)inheritance of acquired characters
Q: With reference to the human body, consider the following statements: 1. The production of somatotropin goes up when a person exercises. 2. Men’s testes produce progesterone. 3. Women’s adrenal glands secrete testosterone. 4. Stress causes the adrenals to release very little cortisol compared to usual. Which of these statements are correct?
(a)2 4 3 1
(b)1 3 4 2
(c)2 3 4 1
(d)1 4 3 2
Q: In a bisexual flower, if androecium and gynaecium mature at different times, the phenomenon is known as
(a)Dichogamy
(b)Herkogamy
(c)Heterogamy
(d)Monogamy
Q: Which one of the following statements is correct?
(a)All echinoderms are viviparous
(b)Round worm has no circulatory system
(c)In bony fishes, swim bladder is usually present
(d)In cartilaginous fishes, fertilisation is internal
Q: Assertion (A): Drinking of whisky increases the frequency of urination. Reason (R): Alcohol intake speeds up the secretion of vasopressin in the body.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is not a correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: Which of the following cell organelles play the most significant role in protein synthesis?
(a)Lysosome and Centrosome
(b)Endoplasmic reticulum and Ribosome
(c)Golgi apparatus and Mitochondria
(d)Lysosome and Mitochondria
Q: The cellular and molecular control of programmed cell death is known as
(a)Apoptosis
(b)Ageing
(c)Degeneration
(d)Necrosis
Q: Which organelle in the cell, other than nucleus, contains DNA?
(a)Centriole
(b)Golgi apparatus
(c)Lysosome
(d)Mitochondrion
Q: Epiphytes are plants which depend on other plants for
(a)food
(b)mechanical support
(c)shade
(d)water
Q: Antigen is a substance which
(a)destroys harmful bacteria
(b)is used to treat poisoning
(c)lowers body temperature
(d)stimulates formation of antibody
Q: Match List I with List II and select the correct answer using the codes given below the Lists: List I (Bone) I. Breast-bone II. Collar-bone III. Knee-cap IV. Shoulder blade List II (Name) A) Clavicle B) Patella C) Scapula D) Sternum
(a)I-D, II-A, III-C, IV-B
(b)I-A, II-D, III-C, IV-B
(c)I-A, II-D, III-B, IV-C
(d)I-D, II-A, III-B, IV-C
Q: Consider the following statements: I. Tapeworm is a hermaphrodite. II. Round-worm has separate sexes. III. Filaria is caused by a nematode. IV. Guinea worm is an annelid. Which of these are correct?
(a)I and II
(b)I, II and III
(c)III and IV
(d)II, III and IV
Q: A man whose blood group is not known meets with a serious accident and needs blood transfusion immediately. Which one of the blood groups mentioned below and readily available in the hospital will be safe for transfusion?
(a)O, Rh-
(b)O, Rh+
(c)AB, Rh-
(d)AB, Rh+
Q: Match List I with List II and select the correct answer using the codes given below the Lists: List I (Substance) I. Ptyalin II. Pepsin III. Renin IV. Oxytocin List II (Physiological role) A) Converts angiotensinogen in blood into angiotensin B) Digests starch C) Digests proteins D) Hydrolyses fats E) Induces contraction of smooth muscles
(a)I-B, II-C, III-A, IV-E
(b)I-C, II-D, III-B, IV-E
(c)I-B, II-C, III-E, IV-A
(d)I-C, II-A, III-B, IV-D
Q: At which stage in its life-cycle does the silkworm yield the fibre of commerce?
(a)Egg
(b)Larva
(c)Pupa
(d)Imago
Q: Match List I (Endocrine glands) with List II (Hormones secreted) and select the correct answer using the codes given below the Lists: List I I. Gonads II. Pituitary III. Pancreas IV. Adrenal List II A) Insulin B) Progesterone C) Growth hormones D) Cortisone Codes:
(a)I-C, II-B, III-D, IV-A
(b)I-B, II-C, III-D, IV-A
(c)I-B, II-C, III-A, IV-D
(d)I-C, II-B, III-A, IV-D
Q: The sensation of fatigue in the muscles after prolonged strenuous physical work is caused by
(a)a decrease in the supply of oxygen
(b)minor wear and tear of muscle fibres
(c)the depletion of glucose
(d)the accumulation of lactic acid
Q: Match the hormones in List I with items in List II and select the correct answer using the codes given below the Lists: List I I. Adrenaline II. Estrogen III. Insulin IV. Pheromones List II A) Anger, fear, danger B) Attracting partners through sense of smell C) Females D) Glucose Codes:
(a)I-C, II-A, III-D, IV-B
(b)I-A, II-C, III-B, IV-D
(c)I-A, II-C, III-D, IV-B
(d)I-C, II-A, III-B, IV-D
Q: Neem tree has acquired industrial importance as a source of
(a)biopesticide and anti-fertility compound
(b)anti-fertility compound, biofertilizer and anti-cancer drug
(c)biofertilizer, biopesticide and anti-fertility compound
(d)anti-cancer drug, biopesticide and biofertilizer
Q: For which one of the following is capillarity not the only reason?
(a)Blotting of ink
(b)Rising of underground water
(c)Spread of water drop on a cotton cloth
(d)Rising of water from the roots of a plant to its foliage
Q: When ants bite, they inject
(a)glacial acetic acid
(b)methanol
(c)formic acid
(d)stearic acid
Q: Match List I with List II and select the correct answer using the codes given below the lists: List I I. Fruit II. Seed III. Wood IV. Starch List II A) Ovule B) Leaf C) Stem D) Ovary
(a)I-B, II-A, III-E, IV-D
(b)I-D, II-A, III-C, IV-B
(c)I-B, II-C, III-A, IV-D
(d)I-D, II-C, III-A, IV-B
Q: Which one of the following statements regarding starch and cellulose is NOT correct?
(a)Both of them are of plant origin
(b)Both of them are polymers
(c)Both of them give colour with iodine
(d)Both of them are made up of glucose molecules
Q: The complete conversion of glucose in the presence of oxygen into carbon dioxide and water with release of energy is called
(a)aerobic respiration
(b)anaerobic respiration
(c)glycolysis
(d)hydrolysis
Q: The pituitary gland by virtue of its tropic hormones controls the secretory activity of other endocrine glands. Which one of the following endocrine glands can function independent of the pituitary gland?
(a)Thyroid
(b)Gonads
(c)Adrenals
(d)Parathyroid
Q: Oxygen transportation in a human body takes place through I. Blood II. Lungs III. Tissue The correct sequence of transportation is
(a)I, II, III
(b)III, I, II
(c)II, I, III
(d)I, III, II
Q: Corpus luteum is a mass of cells found in
(a)brain
(b)ovary
(c)pancreas
(d)spleen
Q: Alpha-keratin is a protein present in
(a)blood
(b)skin
(c)wool
(d)eggs
Q: Arteries supplying blood to the heart are called
(a)carotid arteries
(b)hepatic arteries
(c)coronary arteries
(d)pulmonary arteries
Q: Antigen is a substance which
(a)lowers body temperature
(b)destroys harmful bacteria
(c)triggers the immune system
(d)is used as an antidote to poison
Q: Which one of the following is a modified stem?
(a)Carrot
(b)Sweet potato
(c)Coconut
(d)Potato
Q: Fat present below the skin surface in our body acts as a barrier against
(a)loss of heat from the body
(b)loss of essential body fluids
(c)loss of salts from the body
(d)entry of harmful micro-organisms from the environment
Q: Which one of the following is NOT an essential micronutrient for plants?
(a)Boron
(b)Zinc
(c)Sodium
(d)Copper
Q: Living organisms require at least 27 elements, of which 15 are metals. Among these, those required in major quantities include
(a)Potassium, Manganese, Molybdenum & Calcium
(b)Potassium, Molybdenum, Copper & Calcium
(c)Potassium, Sodium, Magnesium & Calcium
(d)Sodium, Magnesium, Copper & Manganese
Q: Match List I with List II and select the correct answer using the codes given below the lists: List I I. Vitamin II. Enzyme III. Hormone IV. Protein List II A. Pepsin B. Carotene C. Keratin D. Progesterone
(a)I – A, II – B, III – C, IV – D
(b)I – B, II – A, III – D, IV – C
(c)I – B, II – A, III – C, IV – D
(d)I – A, II – B, III – D, IV – C
Q: Match List I (Physiological processes) with List II (Cell organelles) and select the correct answer by using the codes given below the lists: List I I. Photosynthesis II. Mineral uptake III. Respiration IV. Protein Synthesis List II A) Plasma membrane B) Chloroplast C) Mitochondria D) Ribosomes Codes:
(a)I-A, II-B, III-C, IV-D
(b)I-A, II-B, III-D, IV-C
(c)I-B, II-A, III-C, IV-D
(d)I-B, II-A, III-D, IV-C
Q: The Nobel Prize for deciphering the language of bees was awarded to
(a)H. G. Khurana
(b)K. V. Frisch
(c)Julian Huxley
(d)Dorothy Hodgkins
Q: A person with ‘AB’ blood group is sometimes called a universal recipient because of the
(a)lack of antigen in his blood
(b)lack of antibodies in his blood
(c)lack of both antigens and antibodies in his blood
(d)presence of antibodies in his blood
Q: Which one of the following is a membrane that protects the developing embryo from desiccation?
(a)Amnion
(b)Allantois
(c)Chorion
(d)Yolk sac
Q: Most of the desert plants bloom during night time because
(a)their blooming is controlled by low temperature
(b)they are sensitive to the phases of moon
(c)the desert insects eat away flowers during day time
(d)the desert insects are active during night time
Q: The only snake that builds a nest is
(a)Chain viper
(b)King Cobra
(c)Krait
(d)Saw scaled viper
Q: Which of the following elements are present in all proteins? I. Carbon II. Hydrogen III. Oxygen IV. Nitrogen Select the correct answer from the codes given below:
(a)I and II
(b)I, II and IV
(c)I, III and IV
(d)I, II, III and IV
Q: Which one of the following hormones contains iodine?
(a)Thyroxine
(b)Testosterone
(c)Insulin
(d)Adrenaline
Frequently Asked Questions
How many UPSC Prelims questions have been asked from Biology?▼
UPSC has asked 96 questions on Biology in GS Paper 1 Prelims between 1995 and 2024. This sub-topic falls under Science & Technology.
In which years has UPSC asked about Biology?▼
Questions on Biology have appeared in UPSC Prelims in the following years: 2024, 2022, 2021, 2020, 2019, 2014, 2013, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000, 1999, 1998, 1997, 1996, 1995. The topic has appeared in 24 out of 31 years.
What is the difficulty level of Biology questions in UPSC Prelims?▼
Among 96 questions on Biology: 69 are easy, 27 are moderate, and 0 are difficult. Most questions test conceptual understanding of the topic.