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Biology & Human Body — UPSC Prelims Science & Environment previous year questions — page 2

213 solved previous year questions on Biology & Human Body, papers from 1993 to 2023, drawn from UPSC CSE Prelims, UPPCS, UPSC CDS. Each carries the printed answer key and the explanation from the source compilation.

1. #41UPPCS 2017
   Which of the following pairs is not correctly matched? (Ffor.m,one) (Function)
   • AInsulin Regulation of blood glucose
   • BMelatonin Regulation of sleep
   • COxytocin Release milk from mammary glands
   • DGastrin Regulation of blood pressure 1
   Answer: (D) Gastrin Regulation of blood pressure 1
   Explanation

   Option d is the correct Regulation of blood pressure. This pair is matched because gastrin is a hormone the secretion of gastric acid in the stomach, regulation of blood is a hormone that regulates the level of glucose in by facilitating its uptake by the is a hormone that regulates the sleep-wake influencing the circadian is a hormone that stimulates the contraction uterus during labor and the release of milk from glands during lactation

2. #42UPPCS 2017
   Consider the following statements: Assertion (A): Human body is incapable of digesting cellulose. Reason Starch degrading enzyme, diastase, is found in human body. Choose the correct answer from the code given below
   • ABoth (A) and (R) are true, and (R) is the correct explanation of (A)
   • BBoth (A) and (R) are 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
   Answer: (B) Both (A) and (R) are true, but (R) is not the correct explanation of (A)
   Explanation

   Assertion (A) is true: Vitamin Bl 2, also known as Option b is the correct answer. can be stored in the liver for an extended period, (A) is true: The human body is incapable of 3-5 years. This extended storage is because the vitamin cellulose because it lacks the necessary enzyme, bound to proteins in the stomach and intestines, allowing which is required to break down the complex gradual release and utilization by the body over time. molecules found in plant cell walls. Unlike other storage mechanism helps maintain adequate levels of like starch, which can be digested by enzymes even with intermittent dietary amylase, cellulose remains undigested as it the digestive system. Reason (R) is true and (R) is not the correct explanation (R) is true: Diastase is a starch-degrading enzyme (A): Vitamin B12 is indeed a water-soluble vitamin. is found in human saliva and in the pancreas. Diastase

3. #43Previous year
   Consider the following statements: Assertion (A): If somebody stops taking green vegetables, he will suffer from night blindness. Reason He will suffer from vitamin A deficiency. Select the correct answer from the codes given below: [ (Pre) 2011
   • ABoth (A) and (R) are true, and (R) is the correct explanation of (A)
   • BBoth (A) and (R) are 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
   Answer: (D) (A) is false, but (R) is true
   Explanation

   Option d is the correct answer. Assertion (A) is false: While some green vegetables are source of vitamin A, night blindness primarily a deficiency in vitamin A, not specifically from of green vegetables. Vitamin A can also be other food sources like liver, dairy products, (R) is true: Night blindness is a symptom of deficiency, which can occur when there is an of foods rich in vitamin A such as green Other symptoms of vitamin A deficiency eyes, xerophthalmia (a condition in which the dry and cloudy), and keratomalacia (a condition the cornea ulcerates and can lead to blindness)

4. #44UPPCS 2010
   Consider the following statements: Assertion (A): Alum is applied to stop bleeding from cuts. Reason Blood is a colloidal system containing colloidal particles. The Aluminium ions of Alum have high coagulating power, so the blood gets coagulated. Select the correct answer using the code given below
   • ABoth (A) and (R) are true, and (R) is the correct explanation of (A)
   • BBoth (A) and (R) are 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
   Answer: (A) Both (A) and (R) are true, and (R) is the correct explanation of (A)
   Explanation

   Option a is the correct answer ssertion (A) is true: Alum is used as both a in blood (R) is true and correctly explains (A): The ions neutralize the charges on plasma proteins, causing proteins to clump together. This process is as coagulation. Alum also neutralizes the ions on microbes, causing precipitation. The process of is a natural process where a fibrin meshwork is Blood Cells would still get trapped in this with alum, the RBCs would precipitate in this way, alum does help blood clot

5. #45UPPCS 2010
   The atmosphere exerts enormous pressure on us. But we do not feel it because
   • AOur blood exerts a pressure slightly more than that of the atmosphere
   • BWe are used to it
   • COur bones are very strong and can withstand the pressure
   • DThe surface area of our head is very small
   Answer: (A) Our blood exerts a pressure slightly more than that of the atmosphere
   Explanation

   Option a is the correct do not feel the atmospheric pressure because exerts a slightly higher pressure that balances atmospheric pressure is the force or weight of the us. It is measured by an instrument called The atmospheric pressure at sea level is about Hg (millimeters of mercury). The human body at this pressure, because the inside of the body is kept similar pressure, mostly thanks to the blood pressure heart maintains. The blood pressure is usually about Hg (systolic) and 80 mm Hg (diastolic) in healthy means that the blood pressure is slightly higher than pressure, which prevents the gases in the from escaping or expanding. Important Tips If the atmospheric pressure changes, such as when a person goes to a higher altitude or experiences a change in weather, the body may need some time to adjust or acclimatize to the new conditions. A sudden drop in atmospheric pressure can cause

6. #46State PCS 2010
   Fishes survive under the frozen lake, because
   • AFishes have hot blood
   • BFishes are in hibernation under it
   • CWater does not freeze near bottom
   • DIce is the conductor of heat
   Answer: (C) Water does not freeze near bottom
   Explanation

   Option c is the correct can survive under frozen lakes because water freeze near the bottom. This is because water has property of expanding when it freezes. that the densest water is at 4 degrees Celsius. cools below 4 degrees Celsius, it becomes less rises to the surface. This is why ice floats on water at the bottom of the lake remains at 4 even if the surface of the lake freezes over. fish to survive under the are cold-blooded animals, which means that temperature changes with the temperature of This allows fish to survive in cold fish would not be able to survive if the water bottom of the lake froze over. Fish also have a other adaptations that help them to survive in cold example, fish have a thick layer of mucus that helps their bodies. Fish also have a special protein in that prevents their blood from freezing

7. #47UPPCS 2008
   Hydrogen gas can be conveniently used as a fuel for running vehicles if it is absorbed at very low temperature by a substance only to be released at the temperature generated by the exhaust. What is that substance found in India?
   • AHydride
   • BCoals
   • CSoapstone
   • DResins
   Answer: (A) Hydride
   Explanation

   Option a is the correct substance found in India that can be used to hydrogen gas at very low temperatures, to be the temperature generated by the exhaust, is Hydride. Important Tips Hydrides are compounds of hydrogen with other elements. They have the ability to absorb and store hydrogen under certain conditions. This process is known as hydrogen absorption and desorption. Hydrides can serve as a means of storing and releasing hydrogen gas for use in vehicles. This can be particularly important for hydrogen fuel cell vehicles, where a convenient and efficient method of storing hydrogen is crucial

8. #48UPPCS 2001
   Consider the following statements: Assertion (A): Woollen clothes keep us warm. Reason Woollen fibers are made from a special type of protein, which is a bad conductor of heat. Select the correct answer from the codes given below
   • ABoth (A) and (R) are true, and (R) is the correct explanation of (A)
   • BBoth (A) and (R) are 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
   Answer: (C) (A) is true, but (R) is false
   Explanation

   Option c is the correct (A) is correct: Woollen clothes keep us they trap air between their fibers, which is a poor conductor of heat. This prevents the loss of body heat to and keeps us (R) is false: Woollen fibers are not made from type of protein, but from the hair of animals goat, camel, etc. The protein that makes up the hair keratin, which is also found in human hair and is not a bad conductor of heat, but rather a The reason why woolen fibers are poor conductors is because of their structure and arrangement, not composition

9. #49UPPCS 2000
   Consider the following statements: Assertion (A): Some bacteria can synthesize their own food. Reason These bacteria have green matter called chloroplasts. Code
   • ABoth (A) and (R) are true, and (R) is the correct explanation of (A)
   • BBoth (A) and (R) are 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
   Answer: (C) (A) is true, but (R) is false
   Explanation

   Option c is the correct (A) is true: Some bacteria are capable their own food through a process They use various mechanisms, such or chemosynthesis, to convert like carbon dioxide and water into like glucose. This ability to produce their distinguishes them from heterotrophic organisms on external sources for (R) is false: Chloroplasts are specialized in plant cells and certain protists, not in contain chlorophyll, a green pigment that for photosynthesis, the process by which convert sunlight into energy. Bacteria do chloroplasts; instead, some photosynthetic structures called chromatophores or thylakoids them to carry out photosynthesis, but these from chloroplasts. 0 An organism that Its Plants some Bacterja Phytoplankton

10. #50UPPCS 1995
    Which of the following statements about bacteria is correct?
    • AThey are on the borderline of living and non-living
    • BThey are on the borderline of plants and animals
    • CThey are on the borderline of flowering and non-flowering plants
    • DNone of the above
    Answer: (D) None of the above
    Explanation

    Option d is the correct a is incorrect: Bacteria are considered They exhibit various life processes such reproduction, and response to stimuli. They on the borderline of living and b is incorrect: Bacteria are distinct from and animals. They belong to a separate category c is incorrect: Bacteria are neither flowering plants. They are prokaryotic from plants which are typically eukaryotic none of the given options accurately describe of bacteria

11. #51UPPCS 1994
    Which of the following is correct?
    • AAll the blood in the body is absorbed through the kidneys
    • BAll the blood in the body passes through the kidneys
    • CAll the blood in the body is filtered through the kidneys
    • DAll the blood in the body is made through the kidneys
    Answer: (C) All the blood in the body is filtered through the kidneys
    Explanation

    Option c is the correct kidneys are two bean-shaped organs that filter extra fluid from your blood. They also maintain balance of water, salts, and minerals in your make hormones that help control your blood red blood cells, and keep your bones strong and kidneys have about a million filtering units Each nephron has a filter, called the a tubule. The glomerulus filters your blood and the tubule returns needed substances to and removes wastes. The rate of filtration in the approximately 125 ml/min or 45 gallons (180 liters) This means that your entire blood volume (about 7 to gets filtered about 20 to 25 times each day. The and wastes become urine, which flows from the the bladder through two thin tubes called ureters

12. #52UPSC CDS 2023
    Which one of the following is the correct order of pH for the given substances?
    • ALemon Milk of magnesia Blood
    • BMilk of magnesia Blood Coffee Lemon juice
    • CLemon juice Blood Coffee Milk of magnesia
    • DLemon juice Coffee Blood Milk of magnesia
    Answer: (D) Lemon juice Coffee Blood Milk of magnesia
    Explanation

    Option d is the correct correct answer is (c) Lemon Blood Coffee of magnesia. Lemon juice is known for its acidic nature and has a low pH. It typically has a pH range of around 2 to 3, making it quite acidic. Coffee, depending on the type and brewing method, can vary in pH. Generally, coffee is slightly acidic, with a p range of 4 to 5. Blood has a slightly alkaline pH in the range of 7.35 to 7.45. It is slightly basic compared to neutral pH, but sti within the physiological range for human blood. Milk of magnesia is an antacid and is used to neutralize excess stomach acid. It has a higher pH, typically around 10.5 to 11.5, making it alkaline

13. #53UPSC CDS 2023
    If the red blood cells (RBCs) of human blood are isolated and are diluted in normal saline (an isotonic solution to blood), what will happen to the RBCs?
    • AThe RBCs will swell
    • BThe RB Cs will swell and burst
    • CThe RBCs will shrink
    • DNo change in the diameters of the RB Cs
    Answer: (D) No change in the diameters of the RB Cs
    Explanation

    Option d is the correct red blood cells (RBCs) are isolated and diluted in solution like normal saline, there will be no of water across the cell membrane. have the same osmotic pressure as the the RBCs, meaning there is no concentration gradient water movement into or out of the a result, the RBCs will remain in their original shape They will neither swell nor shrink because the inside and outside the cells is balanced

14. #54UPSC CDS 2023
    Which one of the following statements regarding bile secreted by liver is not correct?
    • ABile contains enzymes for digestion of lipids
    • BBile facilitates emulsification of fats
    • CBile neutralizes the acidic
    • DBile makes the pH of the food
    Answer: (A) Bile contains enzymes for digestion of lipids
    Explanation

    Option a is the correct answer. Bile does not contain any enzymes for digestion of only aids in the digestion of lipids by emulsifying making them more accessible to the lipase enzymes secreted by the pancreas and the intestinal mucosa. Important Tips: Bile is a yellow-green fluid that is produced by the liver and stored in the gallbladder. Bile has several functions in digestion, such as: It helps break down fats into smaller droplets ( emulsification) that can be attacked by lipase enzymes. It helps neutralize the acidic chyme (partially digested food) that comes from the stomach and creates a suitable pH for the enzymes in the small intestine. It helps solubilize cholesterol and fat-soluble vitamins (A, and K) and facilitate their absorption across the intestinal wall. It helps eliminate waste products, such as bilirubin and excess cholesterol, from the body through feces

15. #55UPSC CDS 2023
    In plant cells, RNA is present in
    • Acytoplasm only
    • Bnuclei and cytoplasm only
    • Cnuclei, cytoplasm, mitochondria, chloroplast and endoplasmic reticulum
    • Dnuclei, cytoplasm, mitochondria, chloroplast and ribosomes
    Answer: (D) nuclei, cytoplasm, mitochondria, chloroplast and ribosomes
    Explanation

    Option d is the correct plant cells, RNA (ribonucleic acid) is present in compartments and serves different functions. found everywhere nucleus, nucleolus, ribosomes, cytoplasm, etc. RNAs are types- mRNA, tRNA and rRNA. mRNA and found in the cytoplasm and rRNA in the ribosomes can be free within the cytoplasm of a cell to the endoplasmic reticulum but do not the nucleus. RNA and ribosomes act together the synthesis of proteins

16. #56UPSC CDS 2023
    Xylem is a type of complex tissue in plants for upward conduction of water. Which one of the following xylem tissues consists of living cells?
    • ATracheid
    • BVessel
    • CXylem parenchyma
    • DXylem fibre
    Answer: (C) Xylem parenchyma
    Explanation

    Option c is the correct parenchyma consists of living cells. These involved in various functions, such as storage of food and lateral conduction of water and nutrients. thin cell walls and can undergo metabolic activities. Important Tips: Xylem is a complex tissue in plants that is responsible for the upward conduction of water, minerals, and nutrients from the roots to the rest of the plant. Xylem tissue is composed of several cell types, including tracheids, vessels, xylem parenchyma, and xylem fibers. Xylem fibers are another type of cell in xylem that provide mechanical support to the plant. They have -th and are dead at maturity

17. #57UPSC CDS 2022
    Which one of the following statements is not correct with regard to genetically modified organisms?
    • AIn this technique a gene from on organism is isolated and transferred to the cell of another organism
    • BThis technique has applications only in plants
    • CGenes for insect resistance may spread from crop plants to wild plants
    • DTo produce a transgenic animal the novel genes are inserted at a very early stage of development
    Answer: (B) This technique has applications only in plants
    Explanation

    Option b is the correct are not limited to plants; genetic have been applied to animals, humans. Genetically modified animals like mice in medical research

18. #58UPSC CDS 2022
    Which one of the following statements is correct about the cell membrane?
    • AIt is made up of cellulose
    • BIt is a permeable structure for all substances
    • CIt is flexible and enables the cell to engulf many materials
    • DIt does not allow diffusion of gases like oxygen and carbon dioxide
    Answer: (C) It is flexible and enables the cell to engulf many materials
    Explanation

    Option c is the correct cell membrane is selectively permeable, allowing to diffuse through and larger molecules to via facilitated diffusion or active transport. membrane is flexible, which allows the cell to This flexibility allows the cell to engulf other particles, a process called phagocytosis

19. #59UPSC CDS 2022
    The disease rickets develops in children due to the deficiency of
    • AVitamin C
    • BVitamin D
    • CVitamin A
    • DVitamin B
    Answer: (B) Vitamin D
    Explanation

    Option b is the correct is a disease that develops in children due to of vitamin D. Rickets is characterized by bones that are easily deformed. Children with have bowed legs, knock-knees, and a potbelly. They have dental problems and delayed growth. Important Tips Vitamin D is essential for the absorption of calcium and phosphorus from the gut. Calcium and phosphorus are essential for the formation of strong bones. In the absence of vitamin the body is unable to absorb calcium and phosphorus properly, which can lead to the development of rickets. Rickets can be prevented by ensuring that children get enough vitamin D from their diet or from sunlight exposure. Vitamin D is found in oily fish, egg yolks, and fortified milk. Children should also get regular exposure to sunlight. Vitamin A is essential for vision, growth, and immunity. It helps to keep the eyes healthy by preventing night bl

20. #60UPSC CDS 2022
    Which one of the following living organisms gives litmus?
    • AProtozoa
    • BVirus
    • CLichen
    • DSaccharomyces
    Answer: (C) Lichen
    Explanation

    Option c is the correct is a water-soluble mixture of different from lichens. Lichens are composite arise from algae or cyanobacteria living among multiple fungi species in a mutualistic relationship. common lichens used to produce litmus are and Lecanora tartarea

21. #61UPSC CDS 2022
    Mutation in a virus is caused due to a change in its
    • Acellsize
    • Bgenetic material
    • Cshape
    • Dcolour
    Answer: (B) genetic material
    Explanation

    Option b is the correct are changes in the genetic material of They can be caused by a number of exposure to radiation, chemicals, or can be harmful, beneficial, or neutral

22. #62UPSC CDS 2022
    Yeast, which is used to make bread, belongs to the group
    • AProtista
    • BFungi
    • CMonera
    • DProtozoa
    Answer: (B) Fungi
    Explanation

    Option b is the correct is a single-celled fungus that is used to make is a type of ascomycete, which means that it by forming ascospores. Yeast is also used in and wine. Fungi are a diverse group of organisms molds, yeasts, and mushrooms

23. #63UPSC CDS 2022
    Which one of the following statements about starch and glycogen is correct?
    • ABoth starch and glycogen are found in plant cells
    • BBoth starch and glycogen are found in animal cells
    • CStarch is present in plant cells and glycogen is present in animal cells
    • DBoth starch and glycogen are present in plant cells as well as animal cells
    Answer: (C) Starch is present in plant cells and glycogen is present in animal cells
    Explanation

    Option c is the correct is a polysaccharide that is found in plant cells. the main source of energy for plants. Glycogen is polysaccharide, but it is found in animal cells. It is source of energy for animals. Important Tips Both starch and glycogen are made up of glucose molecules, but they are structured differently. Starch is made up of long, unbranched chains of glucose molecules, while glycogen is made up of shorter, branched chains of glucose molecules. The branching of the glucose molecules in glycogen makes it more soluble than starch. This allows glycogen to be stored in the liver and muscles, where it can be easily accessed for energy. m

24. #64UPSC CSE Prelims 2023
    Aerial metagenomics best refers to which one of the following situations?
    • ACollecting DNA samples from air in a habitat at one go
    • BUnderstanding the genetic makeup of avian species of a habitat
    • CUsing air-borne devices to collect blood samples from moving animals
    • DSending drones to inaccessible areas to collect plant and animal samples from 1 and surfaces and water bodies 6
    Answer: (A) Collecting DNA samples from air in a habitat at one go
    Explanation

    Option a is the correct answer. erial metagenomics" refers to the collection and DNA samples from the air or aerosol particles present specific habitat. It involves sampling the air in a to capture the genetic material (DNA) microorganisms, including bacteria, viruses, fungi, microscopic organisms

25. #65UPSC CSE Prelims 2023
    DNA' is used in the case of which one of the following?
    • AStudying evolutionary relationships among various species of fauna
    • BStimulating stem cells transform into diverse functional tissues
    • CPromoting clonal propagation of horticultural plant
    • DAssessing the efficacy of drugs by conducting series of drug trials in a population
    Answer: (A) Studying evolutionary relationships among various species of fauna
    Explanation

    Option a is the correct DNA, also known as short tandem is a type of genetic marker that consists of of DNA. It is commonly used in genetic population genetics and phylogenetic analysis, relationships among different species of are highly polymorphic and vary in to differences in the number of repeat units. the variations in microsatellite DNA individuals or populations, researchers can diversity, population structure, and within and between species

26. #66UPSC CSE Prelims 2020
    In the context of recent advances in human reproductive technology, "Pronuclear Transfer" is used for
    • Afertilization of egg in vitro by the donor sperm
    • Bgenetic modification of sperm producing cells
    • Cdevelopment of stem cells into functional embryos
    • Dprevention of mitochondrial diseases in offspring
    Answer: (D) prevention of mitochondrial diseases in offspring
    Explanation

    Option dis the correct transfer (PNT) is a reproductive technology be used to prevent the transmission of from mother to child. Mitochondrial diseases group of genetic disorders that are caused by mitochondrial DNA Mitochondrial DNA down from mother to child, but not from father PNT involves transferring the pronudei (the the sperm and egg) from a fertilized egg from a mitochondrial disease to an enudeated (empty) a healthy donor woman. The resulting embryo the nuclear DNA of the mother and father, but of the donor woman. This means that the child inherit the mitochondrial disease from the mother. Important Tips Characteristic (Nuclear DNA) (Mitochondrial DNA) Location Nucleus Mitochondria Inheritance Both parents- Only mother Father and (Because sperms Mother cells do not contain Mitochondria) Mutations can A variety A variety of genetic cause of genetic disorders, such as disorders, Le

27. #67UPSC CSE Prelims 2019
    Which of the following are the reasons for the occurrence of multi-drug resistance in microbial pathogens in India? 1. Genetic predisposition of some people 2. Taking incorrect doses of antibiotics to cure diseases 3. Using antibiotics in livestock farming 4. Multiple chronic diseases in some peopleSelect the correct answer using the code given below: by joining segments of DNA taken from cells of different species. created in laboratories. cell can be made to replicate outside a living cell in a laboratory. can be made to undergo cell division in laboratory petri dishes
    • A1 and 2 only
    • B2 and 3 only
    • C1, 3 and 4 only
    • D2, 3 and 4 only
    Answer: (B) 2 and 3 only
    Explanation

    Option b is the correct reasons for the occurrence of multi-drug resistance pathogens in India are: Taking incorrect doses of antibiotics to cure diseases: This is a significant factor contributing to drug resistance. When people do not complete their full course of antibiotics, or take incorrect doses, it gives the bacteria a chance to develop resistance to the drug. The surviving bacteria are often the ones that are more resistant, leading to the development of drug-resistant strains. Using antibiotics in livestock farming: Antibiotics are often used in livestock farming for growth promotion and disease prevention. When antibiotics are used in this manner, it can lead to the development of drug resistant bacteria in animals. These bacteria can then be transmitted to humans through consumption of contaminated meat or through environmental predisposition and multiple chronic diseases peo

28. #68UPSC CSE Prelims 2019
    What is protein that is often mentioned in news?
    • AA molecular scissors used in targeted gene editing
    • BA biosensor used in the accurate detection of pathogens in patients
    • CA gene that makes plants pest-resistant
    • DA herbicidal substance synthesized in genetically modified crops
    Answer: (A) A molecular scissors used in targeted gene editing
    Explanation

    Short Palindromic Repeats) system, which is a Option a is the correct answer. immune system that protects bacteria from viruses. is used in a variety of research applications, including protein is a molecular scissors that is used in development of new treatments for diseases. It is also gene editing. It is a nuclease enzyme that can be used to develop new crops that are resistant to pests to cut DNA at specific sequences. is from the CRISPR (Clustered Regularly attaches.t-, ganomle DNA segment) 53. Solution: (a) Exp) Option a is the correct answer. Statement 1 is correct can be used to silence the expression of specific genes, which could be used to treat a variety of diseases, including cancer, genetic disorders, and infectious diseases. Statement 2 is correct can be used to target cancer cells and silence the genes that are essential for their growth and survival. This could lead to n

29. #69UPSC CSE Prelims 2018
    With reference to the Genetically Modified mustard ( GM mustardeveloped in India, consider the following statements: 1. GM mustard has the genes of a soil bacterium that give the plant the property of pest-resistance to a wide variety of pests. 2. GM mustard has the genes that allow the plant cross-pollination and hybridization. 3. GM mustard has been developed jointly by the IARI and Punjab Agricultural University.Which of the statements given above is/are correct?
    • A1 and 3 only
    • B2 only
    • C2 and 3 only
    • D1, 2 and 3
    Answer: (B) 2 only
    Explanation

    According to the directive issued by CERT-In on 28 Option b is the correct answer. 2022, it is legally mandatory for all the following l is incorrect- GM mustard has been developed to report on cyber security incidents within six hours the genes that make it resistant to pests like whiteflies noticing the incident or being brought to aphids, not from a soil bacterium. The genes that have Service inserted into GM mustard come from a wild mustard Data called Diplotaxis harra. Body 2 is correct- GM mustard has the genes that plant to cross-pollinate and hybridize. This is because Important GM mustard variety DMH-11 was developed using a CERT-In stands for Computer Emergency called heterosis breeding, which requires cross- Team - between two different parental lines. It is an office within the Ministry of Electronics 3 is incorrect- The Delhi University's Centre Information Technology of the

30. #70UPSC CSE Prelims 2017
    With reference to agriculture in India, how can the technique of 'genome sequencing', often seen in the news, be used in the immediate future? I. Genome sequencing can be used to identify genetic markers for disease resistance and drought tolerance in various crop plants. 2. This technique helps in reducing the time required to develop new varieties of crop plants. 3. It can be used to decipher the host pathogen relationship in crops.Select the correct answer using the code given below
    • A1 only
    • B2 and 3 only
    • C1 and 3 only
    • D2 and 3
    Answer: (D) 2 and 3
    Explanation

    Option d is the correct 1 is correct- Genome sequencing can be identify genetic markers for disease resistance tolerance in various crop plants. Genetic DNA sequences that are associated with specific identifying genetic markers for disease resistance tolerance, scientists can develop new varieties plants that are resistant to these stresses. For have used genome sequencing to identify a that is associated with resistance to the rice This marker can be used to breed new varieties that are resistant to this 2 is correct- Traditional breeding methods many years to develop new varieties of crop traits. Genome sequencing can help ti me required to develop new varieties of crop identifying genetic markers for desired traits. can tlien be used to select plants for are more likely to have the desired 3 is correct- The host-pathogen relationship interaction between a plant and a pathogen, such a

31. #71UPSC CSE Prelims 2016
    India is an important member of the 'International Thermonuclear Experimental If this experiment succeeds, what is the immediate advantage for India?
    • AIt can use thorium in place of uranium for power generation
    • BIt can attain a global role in satellite navigation
    • CIt can drastically improve the efficiency of its fission reactors in power generation
    • DIt can build fusion reactors for power generation
    Answer: (D) It can build fusion reactors for power generation
    Explanation

    Option dis the correct aim of the International Thermonuclear (ITER) project, which began in 2006, is to nuclear fusion can be a source of energy in the future. Important Tips Fusion is the energy source of the Sun and stars. In the tremendous heat and gravity at the core of these stellar bodies, hydrogen nuclei collide, fuse into heavier helium atoms and release tremendous amounts of energy in the process

32. #72UPSC CSE Prelims 2015
    With reference to the use of nanotechnology in the health sector, which of the following statements is/are correct:? 1. Targeted drug delivery is made possible by nanotechnology. 2. Nanotechnology can largely contribute to gene therapy.Select the correct answer using the code given below
    • A1 only
    • B2 only
    • CBoth 1 and 2
    • DNeither 1 nor 2 97
    Answer: (C) Both 1 and 2
    Explanation

    Option c is the correct 1 is correct- Nanotechnology can be used nanoparticles that can deliver drugs directly to tissue or organ. This can be done by attaching to the surface of the nanoparticle or by drug inside the nanoparticle. Targeted drug help to reduce the side effects of drugs and efficacy Statement 2 is correct- Nanotechnology can to gene therapy. In gene therapy, Enhance targeted gene delivery, improving therapy effectiveness while reducing side effects. Innovate precise gene editing tools like nanoparticles for disease correction. Enable theranostics, merging diagnostics and treatment monitoring for optimized care. Important Tips What is is a gene editing technology that allows scientists to make precise changes to DNA. It is based on a naturally occurring immune system that bacteria use to defend themselves against viruses. The system consists of two key components: enzyme:

33. #73UPSC CSE Prelims 2012
    Consider the given statements - 1. BT brinjal is created by inserting in its genome, the gene of soil fungus. 2. The seeds of BT brinjal are terminator seed so farmers have to buy it before every weather from seed companies. 3. This is also a fact that it can affect the user's health negatively. 4. The other threat is that its insertion may affect adversely biodiversity. Choose the right answer according to these codes
    • AOnly 1, 2 3
    • BOnly 2 3
    • COnly 3, 4
    • D1, 2, 3 4
    Answer: (C) Only 3, 4
    Explanation

    Option c is the correct l is incorrect- Bt brinjal is created by its genome, the gene of a soil bacterium called 2 is incorrect- Terminator seeds are seeds that are designed to be sterile. This farmers cannot save seeds from their harvest and new seeds from the seed company each year. Bt brinjal seeds are not terminator seeds. Farmers can from their Bt brinjal harvest and plant them 3 is correct- A study done on rats suggests eaten regularly by humans, Bt brinjal would hit in the body, liver damage, and 4 is correct- The insertion of the Bt brinjal could potentially have adverse effects For example, the Bt protein could be toxic insects, such as beneficial insects that help other pests. Additionally, the Bt gene could other plants in the environment, creating new weeds resistant to Bt insecticides. Important Tips Regulatory Authorities for Genetically Modified Crops and Foods in India: F

34. #74UPSC CSE Prelims 2012
    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 code given below
    • A1 and 2 only
    • B3 and 4 only
    • C1, 2 and 4 only
    • D1, 2, 3 and 4
    Answer: (C) 1, 2 and 4 only
    Explanation

    Option c is the correct l is correct- Genetically engineered plants droughts because scientists can insert genes that make them more drought-tolerant. For have inserted genes into plants that make more osmoprotectants, which are molecules plants retain 2 is correct- Genetically engineered plants created to have higher levels of vitamins, minerals, nutrients. This could help to improve the health who eat these 3 is incorrect- Genetically engineered grow and do photosynthesis in space stations because: Plant's gravity-sensing system- In microgravity, plant's root does not know which way to grow, and plant's shoot can become spindly and weak. Low light condition. High levels of radiation. Limited nutrients and 4 is correct- Genetically engineered plants created to have a longer shelf life. This could waste and make it possible to transport food

35. #75UPSC CSE Prelims 2012
    What is the role of ultraviolet (UV) radiation in the water purification systems? 1. It inactivates /kills the harmful microorganisms in water. 2. It removes all the undesirable odors from the water. T 3. It quickens the sedimentation of solid particles, removes turbidity and improves the clarity of water.Which of the statements given above is/are correct?
    • A1 only
    • B2 and 3 only
    • C1 and 3 only
    • D1, 2 and 3
    Answer: (A) 1 only
    Explanation

    Option a is the correct answer. water purification is the most effective disinfecting bacteria from the water. Ultraviolet penetrate harmful pathogens in water and microorganisms by attacking their (DNA)

36. #76UPSC CSE Prelims 2012
    With reference to 'stem cells', frequently in the news, which of the following statements is/are correct? 1. Stem cells can be derived from mammals only. 2. Stem cells can be used for screening new drugs. 3. Stem cells can be used for medical therapies.Select the correct answer using the codes given below
    • A1 and 2 only
    • B2 and 3 only
    • C3 only
    • D1, 2 and 3
    Answer: (B) 2 and 3 only
    Explanation

    Option b is the correct stem cell is a cell with the unique ability to develop cell types in the body. This can range from to brain cells. In some cases, they can also fix cells can be derived from all multicellular not just mammals

37. #77UPSC CSE Prelims 2012
    What are the reasons for the people's resistance to the introduction of Bt brinjal in India? 1. Bt brinjal has been created by inserting a gene from a soil fungus into its genome. 2. The seeds of Bt brinjal are terminator seeds and therefore, the farmers have to buy the seeds before every season from the seed companies. 3. There is an apprehension that the consumption of Bt brinjal may have adverse impact on health. 4. There is some concern the introduction of Bt brinjal may have adverse effect on the biodiversity.Select the correct answer using the codes given below
    • A1, 2 and 3 only
    • B2 and 3 only
    • C3 and 4 only
    • D1, 2, 3 and 4
    Answer: (C) 3 and 4 only
    Explanation

    Option c is the correct brinjal has been created by inserting a crystal protein from the soil bacterium Bacillus thuringiensis genome brinjal does not produce terminator seeds

38. #78UPSC CSE Prelims 2011
    At present, scientists can determine the arrangement or relative positions of genes or DNA sequences on a chromosome. How does this knowledge benefit us? 1. It is possible to know the pedigree of livestock. 2. It is possible to understand the causes of all human diseases. 3. It is possible to develop disease-resistant animal breeds.Which of the statements given above is/are correct?
    • A1 and 2
    • B2 only
    • C1 and 3
    • D1, 2, and 3
    Answer: (C) 1 and 3
    Explanation

    Option c is the correct 1 is correct- It is possible to know the livestock through the knowledge of the relative positions of genes or DNA sequences on This can be used to improve the breeding and to produce animals with desirable traits, high milk production or resistance to 2 is incorrect- Knowing the relative positions of genes or DNA sequences on is not enough to understand the causes human diseases. This is because human diseases and are caused by a variety of factors, environment, and lifestyle. While genetics important role in many diseases, it is not the only 3 is correct- It is possible to develop disease resistant animal breeds through the knowledge of or relative positions of genes or DNA a chromosome. This can be done by identifying genes that are associated with disease animal breeds can help to reduce the use and other medications in agriculture

39. #79Previous year
    A genetically engineered form of brinjal, known as the Bt. brinjal has been developed. The objective of this is - [UPSC CSE Pre 201 l
    • ATo make it pest-resistant
    • BTo improve its taste and nutritive qualities
    • CTo make it drought-resistant
    • DTo make it shelf-life longer
    Answer: (A) To make it pest-resistant
    Explanation

    Option a is the correct brinjal is a genetically engineered brinjal that has to express a protein from the bacterium (Bt). The Bt protein is toxic to certain such as fruit and shoot borer (FSB). FSB is a ofbrinjal and can cause significant crop losses. Bt resistant to FSB and other insect pests that are the Bt protein. Important Tips Genetically Modified Crops in India: Crop Genetic modification Status Bt cotton Two alien genes from Allowed the soil bacterium Bacillus thuringiensis (Bt) allow the crop to develop a protein toxic to the common pest pink bollworm. Ht-Bt An additional gene from Not allowed cotton another soil bacterium allows the plant to resist the common herbicide glyphosate. Bt brinjal A gene allows the plant Moratorium to resist attacks of fruit on commercial and shoot borer. cultivation -11 Genetic modification Not allowed mustard allows cross-pollination in a crop that

40. #80UPSC CSE Prelims 2009
    In the context of genetic disorders, consider the following: A woman suffers from colour blindness while her husband does not suffer from it. They have a son and a daughter. In this context, which one of the following statements is most probably correct?
    • ABoth children suffer from colour blindness
    • BDaughter suffers from colour blindness while son does not suffer from it
    • CBoth children do not suffer from colour blindness
    • DSon suffers from colour blindness while daughter does not suffer from it
    Answer: (D) Son suffers from colour blindness while daughter does not suffer from it
    Explanation

    Option d is the correct blindness is usually passed down from parents to and the genes responsible for the most of colour blindness are on the X chromosome. that males are more likely to be colour blind because they only have one X chromosome and chromosome, while females have two X this case, Son suffers from colour blindness does not suffer from it. This is because the suffers from colour blindness must have two the colour blind gene on her X chromosomes, and pass one of them to each of her children. Her son the colour blind gene from her and will be because he does not have another X chromosome for it. Her daughter will inherit the colour from her and a normal gene from her father, and be colour blind, because she has another X balance it out. She will be a carrier of the colour but she won't show any symptoms

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