CUET Biology Human Welfare Important Questions with Answers 2027 (Download PDF)

Overview: Searching for the most important CUET Biology Human Welfare Important Questions with Answers? You've landed in exactly the right place! This article gives you 30 exam-focused MCQs with easy-to-understand explanations, key highlights, topic-wise breakdown, and expert tips, all based on NCERT Class 12 Biology and the latest CUET exam pattern.

Biology and Human Welfare is one of the most reliable chapters for scoring in the CUET Exam 2027. If you understand this chapter well, you can easily score full marks on questions from it because most questions are direct and come straight from NCERT Class 12 Biology.

To make your revision easy and effective, we have compiled 30 handpicked MCQs on Human Welfare, with clear answers and simple explanations. Download the PDF and start practising now!

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What are CUET Biology Human Welfare Important Questions 2027?

CUET Biology Human Welfare Important Questions are multiple-choice questions (MCQs) that test your understanding of how microorganisms, biotechnology, and biological processes are used to benefit humans and society.

This chapter is officially known as "Biology and Human Welfare" in NCERT Class 12 Biology and covers topics such as:

• Microbes in food production (curd, bread, alcohol, vinegar, cheese)

• Microbes in industrial production (antibiotics, enzymes, bioactive molecules)

• Microbes in sewage treatment (primary, secondary treatment, BOD)

• Microbes in biogas production (methanogens, biogas plants)

• Biocontrol agents (Bacillus thuringiensis, baculoviruses, Trichoderma)

• Biofertilisers (Rhizobium, Azospirillum, Azolla, Mycorrhiza)

In CUET 2027, you can expect types of questions like direct factual questions, organism-product matching type, or application-based MCQs. Regular practice using these CUET Biology Human Welfare Important Questions with Answers will sharpen your accuracy and build strong conceptual clarity.

Pro Tip: Before jumping into the MCQs, make sure you've gone through the CUET Biology Notes for quick revision of this chapter.

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30 Best CUET Biology Human Welfare Important Questions to Practice Now

Q1. Which microorganism is responsible for the production of curd from milk?

(A) Saccharomyces cerevisiae

(B) Lactobacillus

(C) Penicillium notatum

(D) Aspergillus niger

Correct Answer: (B)

Explanation: Lactobacillus is a bacterium that ferments lactose (the sugar present in milk) into lactic acid. This lactic acid causes the milk proteins to coagulate (thicken), which converts milk into curd. Lactobacillus also improves the nutritional quality of curd by increasing Vitamin B12 content. This is one of the most direct and frequently asked questions in this chapter for CUET.

Q2. "Swiss Cheese" gets its characteristic large holes because of which organism?

(A) Lactobacillus bulgaricus

(B) Propionibacterium shermanii

(C) Streptococcus thermophilus

(D) Saccharomyces cerevisiae

Correct Answer: (B)

Explanation: The large holes you see in Swiss cheese are produced by a bacterium called Propionibacterium shermanii. During the ripening of Swiss cheese, this bacterium produces a large amount of carbon dioxide (CO₂), which forms bubbles inside the cheese, creating the characteristic big holes. This is a favourite factual question in competitive exams like CUET and NEET.

Q3. Which of the following organisms is used in the production of the antibiotic Penicillin?

(A) Bacillus subtilis

(B) Streptomyces griseus

(C) Penicillium notatum

(D) Trichoderma polysporum

Correct Answer: (C)

Explanation: Penicillin was the world's first antibiotic, discovered by Alexander Fleming in 1928. It is produced by the fungus Penicillium notatum (also written as Penicillium chrysogenum in modern taxonomy). Penicillin works by inhibiting the synthesis of bacterial cell walls, ultimately killing the bacteria. This discovery revolutionised medicine and saved millions of lives. In CUET, remembering which organism produces which antibiotic is very important.

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Q4. Statins, used to lower blood cholesterol levels, are produced by which organism?

(A) Aspergillus niger

(B) Monascus purpureus

(C) Clostridium butylicum

(D) Rhizopus stolonifer

Correct Answer: (B)

Explanation: Statins are a group of bioactive molecules that act as competitive inhibitors of the enzyme HMG-CoA reductase, which is responsible for cholesterol biosynthesis in the human body. Monascus purpureus, a yeast-like fungus, naturally produces statins. These molecules have become one of the most widely prescribed medicines globally to manage cardiovascular disease. CUET frequently asks which organism produces which industrial product, so this is a must-know fact.

Q5. What does BOD stand for and what does a high BOD value indicate?

(A) Biological Oxygen Demand: indicates clean water

(B) Biochemical Oxygen Demand: indicates clean water

(C) Biological Oxygen Demand: indicates heavily polluted water

(D) Biochemical Oxygen Demand indicates: heavily polluted water

Correct Answer: (D)

Explanation: BOD stands for Biochemical Oxygen Demand. It is the amount of oxygen required by microorganisms to break down (decompose) the organic matter present in a given volume of water. If water has a high BOD, it means there is a large amount of organic pollutants in it, and microorganisms are consuming a lot of oxygen to decompose them. This leaves less dissolved oxygen in the water, making it harmful for aquatic life. Low BOD = clean water; High BOD = polluted water. This concept appears very frequently in CUET exams.

Q6. In the primary treatment of sewage, what process is used to remove solids?

(A) Biological decomposition by aerobic bacteria

(B) Physical filtration and sedimentation

(C) Anaerobic digestion in large tanks

(D) Addition of chemical chlorine

Correct Answer: (B)

Explanation: The primary treatment of sewage is a purely physical process. First, sewage passes through screens that filter out large floating solids like plastic and debris. Then the water passes through a grit chamber where sand, silt, and pebbles settle at the bottom. After this, the water enters a settling tank where small organic and inorganic particles sink as primary sludge. The remaining liquid (called effluent) then moves on to secondary treatment. No chemicals or biological agents are used in this step.

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Q7. During secondary treatment of sewage, what type of bacteria are primarily responsible for decomposing organic matter?

(A) Anaerobic bacteria in settling tanks

(B) Aerobic bacteria in aeration tanks

(C) Methanogens in biogas digesters

(D) Nitrogen-fixing bacteria in activated sludge

Correct Answer: (B)

Explanation: After primary treatment, the effluent flows into large aeration tanks where it is continuously stirred, and air is pumped in. This promotes the growth of aerobic microorganisms, mainly bacteria that decompose organic matter in the sewage. These bacteria form a mesh-like structure called flocs (a mixture of bacteria and fungal filaments). They consume most of the organic waste present, significantly reducing the BOD of the water. This step is called secondary or biological treatment.

Q8. What happens to the activated sludge that settles at the bottom of the settling tank after secondary sewage treatment?

(A) It is directly discharged into rivers

(B) It is used as manure on farmlands directly

(C) A small part is used as inoculum; the remaining is transferred to anaerobic sludge digesters

(D) It is filtered again through screens and discarded

Correct Answer: (C)

Explanation: After secondary treatment in the aeration tank, the water flows into a secondary settling tank. Here, the microbial flocs settle at the bottom as activated sludge. A small portion of this activated sludge is pumped back into the aeration tank to serve as an inoculum (starter culture) for the next batch of incoming sewage. The remaining bulk of activated sludge is pumped into large tanks called anaerobic sludge digesters, where anaerobic bacteria further decompose it, producing biogas (mainly methane) in the process.

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Q9. What is the primary component of biogas produced in a biogas plant?

(A) Carbon dioxide

(B) Hydrogen sulphide

(C) Methane

(D) Nitrogen

Correct Answer: (C)

Explanation: Biogas is a mixture of gases produced by the anaerobic (without oxygen) decomposition of organic waste by microorganisms called methanogens. The composition of biogas is approximately 55–65% methane (CH₄), along with carbon dioxide, hydrogen, and traces of hydrogen sulphide. Methane is combustible and is the main component that makes biogas a usable fuel for cooking and lighting, especially in rural areas of India.

Q10. Which type of bacteria are responsible for producing biogas in a biogas plant?

(A) Lactobacillus

(B) Methanogens

(C) Nitrifying bacteria

(D) Pseudomonas

Correct Answer: (B)

Explanation: Methanogens are a special group of anaerobic bacteria (technically archaea) that live in places with no oxygen and break down complex organic compounds to produce methane (CH₄) and carbon dioxide (CO₂). In biogas plants, cattle dung, agricultural waste, and food waste are mixed with water and fed into an enclosed digester tank where methanogens carry out this decomposition. Methanogens are also found naturally in the rumen (stomach) of cattle, marshes, and at the bottom of swamps.

Q11. Which of the following is a commonly used biocontrol agent against insect pests?

(A) Saccharomyces cerevisiae

(B) Bacillus thuringiensis

(C) Rhizobium leguminosarum

(D) Azospirillum brasilense

Correct Answer: (B)

Explanation: Bacillus thuringiensis (commonly called Bt) is a naturally occurring soil bacterium that produces protein crystals toxic to specific insect larvae. When insect larvae ingest these crystals, the proteins are activated by the alkaline pH of their gut, creating pores in the gut wall, leading to the death of the insect. Bt has been used as a biopesticide in agriculture for decades and is the basis for genetically engineered Bt crops (like Bt cotton and Bt brinjal). Importantly, Bt toxin is harmless to humans, animals, and beneficial insects like honeybees.

Q12. Baculoviruses are used as biocontrol agents. Which group of organisms do they specifically target?

(A) Fungi infecting crop plants

(B) Weeds competing with food crops

(C) Insects and arthropods

(D) Soil-borne bacterial pathogens

Correct Answer: (C)

Explanation: Baculoviruses are a group of insect-specific viruses that are highly effective biocontrol agents. They infect and kill insects and arthropods (like mites and spiders) without causing any harm to plants, mammals, birds, fish, or even non-target insects like beneficial pollinators. Nucleopolyhedrovirus (NPV) is the most widely used type. Baculoviruses are particularly significant in organic farming and integrated pest management (IPM) programs because they offer species-specific pest control with no chemical residues.

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Q13. The fungus Trichoderma is used in biological control to combat which type of pathogen?

(A) Viruses infecting vegetable crops

(B) Insects attacking stored grain

(C) Plant pathogenic fungi

(D) Nematodes in soil

Correct Answer: (C)

Explanation: Trichoderma is a naturally occurring soil fungus that acts as a powerful biocontrol agent against several plant pathogenic fungi like Pythium, Fusarium, Rhizoctonia, and Sclerotinia. It works through multiple mechanisms it produces antibiotics and enzymes that destroy the cell walls of pathogenic fungi, and it also competes with them for space and nutrients in the soil. Trichoderma-based biofungicides are widely available in India and are used extensively in vegetable and fruit crop cultivation.

Q14. Which of the following is an example of a Ladybird beetle being used as a biocontrol agent?

(A) It controls fungal infections in wheat

(B) It feeds on aphids and other plant lice

(C) It acts as a pollinator for fruit crops

(D) It is used to improve soil nitrogen content

Correct Answer: (B)

Explanation: The Ladybird beetle (also known as Ladybug) is a classical example of a predatory biocontrol agent. Both adult ladybirds and their larvae are voracious predators of soft-bodied insects, especially aphids (plant lice), mealybugs, and scale insects. A single ladybird can consume hundreds of aphids per day. This makes it a highly effective, natural, and environmentally safe option for controlling pest populations in agriculture without any chemical pesticides. Similarly, Dragonflies are used to control mosquito populations.

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Q15. Which bacteria form a symbiotic association with the roots of leguminous plants to fix atmospheric nitrogen?

(A) Azospirillum

(B) Azolla

(C) Rhizobium

(D) Anabaena

Correct Answer: (C)

Explanation: Rhizobium is a nitrogen-fixing bacterium that forms a mutualistic (mutually beneficial) symbiotic relationship with the roots of leguminous plants like pea, beans, clover, and soybean. The bacteria infect the root cells and form structures called root nodules. Inside these nodules, Rhizobium uses an enzyme called nitrogenase to convert atmospheric nitrogen (N₂) into ammonia (NH₃), which the plant can use as a nutrient. In return, the plant provides carbohydrates and shelter to the bacteria. This is an extremely common CUET and NEET question.

Q16. Azospirillum is used as a biofertiliser. What is its primary function?

(A) It fixes phosphorus for cereal crops

(B) It forms root nodules in leguminous plants

(C) It fixes atmospheric nitrogen in association with roots of cereals and other crops

(D) It produces antibiotics to protect plant roots

Correct Answer: (C)

Explanation: Azospirillum is a free-living nitrogen-fixing bacterium that associates loosely (not forming tight nodules) with the roots of non-leguminous crops such as wheat, rice, maize, sugarcane, and other cereals. It fixes atmospheric nitrogen in the soil and makes it available to the plant roots. Azospirillum inoculants are widely used in India as a cost-effective biofertiliser to reduce the dependence on synthetic nitrogen fertilisers, which are expensive and environmentally damaging.

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Q17. Azolla is used as a biofertiliser in paddy (rice) fields. What makes it uniquely useful?

(A) It fixes nitrogen through its symbiotic association with Rhizobium in its roots

(B) It is a free-floating aquatic fern that harbours nitrogen-fixing cyanobacterium Anabaena in its leaves

(C) It is a Mycorrhizal fungus that increases phosphorus uptake in rice roots

(D) It produces growth hormones that stimulate root development in paddy

Correct Answer: (B)

Explanation: Azolla is a tiny aquatic floating fern that is used as a green biofertiliser in paddy (rice) fields, especially in Asian countries including India, China, and Vietnam. What makes Azolla special is that it harbours a nitrogen-fixing cyanobacterium called Anabaena azollae inside its leaves. This cyanobacterium fixes atmospheric nitrogen, and when Azolla decomposes in the field, this fixed nitrogen is released into the soil, enriching it naturally. Azolla can grow very quickly and is an eco-friendly, cost-free way to add nitrogen to rice paddies.

Q18. Which of the following correctly describes Mycorrhiza and its role as a biofertiliser?

(A) It is a bacterium that fixes nitrogen in the roots of legumes

(B) It is a symbiotic association between fungi and roots of higher plants that helps in phosphorus absorption

(C) It is a cyanobacterium found in the leaves of Azolla that fixes nitrogen

(D) It is a Trichoderma species that controls soil-borne pathogens

Correct Answer: (B)

Explanation: Mycorrhiza refers to the mutualistic (mutually beneficial) symbiotic association between certain fungi (mainly from the phylum Glomeromycota) and the roots of higher plants. The fungal hyphae (thread-like structures) greatly increase the surface area of the plant root system, allowing the plant to absorb more water and nutrients, especially phosphorus, from the soil. In return, the plant provides sugars to the fungus. Mycorrhizal inoculants are used as biofertilisers to improve crop yield and reduce dependence on chemical phosphatic fertilisers.

Q19. Which of the following organisms was used by Alexander Fleming to first discover Penicillin?

(A) Aspergillus flavus

(B) Penicillium notatum

(C) Streptomyces venezuelae

(D) Bacillus subtilis

Correct Answer: (B)

Explanation: In 1928, Scottish bacteriologist Alexander Fleming noticed that a culture plate of Staphylococcus bacteria had been accidentally contaminated by a mould, and that bacterial growth was inhibited around the mould. This mould was Penicillium notatum. He identified the antibacterial substance produced by the mould as Penicillin. Later, Howard Florey and Ernst Chain purified and developed Penicillin as a usable drug during World War II. Fleming, Florey, and Chain jointly received the Nobel Prize in Physiology or Medicine in 1945.

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Q20. The antibiotic Streptomycin is derived from which of the following organisms?

(A) Bacillus subtilis

(B) Penicillium chrysogenum

(C) Streptomyces griseus

(D) Aspergillus terreus

Correct Answer: (C)

Explanation: Streptomycin is an important antibiotic that belongs to the aminoglycoside family. It is produced by the soil bacterium z. It was the first effective antibiotic against tuberculosis (TB) and is still used today in combination therapies for drug-resistant TB. Many critically important antibiotics (tetracycline, chloramphenicol, erythromycin) are derived from the genus Streptomyces; these soil bacteria have been one of the most valuable sources of antibiotics ever discovered.

Q21. Cyclosporin A, used as an immunosuppressive drug during organ transplantation, is produced by which organism?

(A) Monascus purpureus

(B) Trichoderma polysporum

(C) Aspergillus niger

(D) Clostridium butylicum

Correct Answer: (B)

Explanation: Cyclosporin A is a powerful immunosuppressive drug used to prevent organ rejection in patients who have undergone kidney, liver, heart, and other organ transplants. It suppresses the immune system so that the body does not attack the transplanted organ. It is produced by the fungus Trichoderma polysporum. This is a high-yield CUET question because students often confuse Trichoderma's role; it is both a biocontrol agent and a source of Cyclosporin A.

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Q22. Streptokinase, used as a "clot buster" in heart attack patients, is produced by which organism?

(A) Aspergillus niger

(B) Bacillus subtilis

(C) Streptococcus

(D) Saccharomyces cerevisiae

Correct Answer: (C)

Explanation: Streptokinase is an enzyme (more precisely, a thrombolytic or fibrinolytic agent) produced by the bacterium Streptococcus. It works by activating plasminogen in the blood, converting it into plasmin, which then breaks down fibrin clots that block blood vessels. Streptokinase is used in emergency medicine to dissolve blood clots in patients suffering from myocardial infarction (heart attack) and pulmonary embolism. The genetically modified form of streptokinase is now more commonly used in clinical settings.

Q23. Lipase enzymes, used in the detergent industry, are produced by which type of microorganism?

(A) Viruses

(B) Protozoa

(C) Microbes (bacteria and fungi)

(D) Algae

Correct Answer: (C)

Explanation: Lipases are enzymes that break down lipids (fats and oils). They are produced commercially by various microorganisms, including bacteria like Pseudomonas and Bacillus species, and fungi like Aspergillus and Candida species. In the detergent industry, lipases are added to washing powders and liquids to help break down oil and grease stains on clothing at low temperatures, making laundry more efficient and energy-saving. This is a practical application of microbial enzymes in everyday life.

Q24. Pectinases and proteases are industrially important enzymes. What is their main use?

(A) Production of biogas from agricultural waste

(B) Clarification of bottled fruit juices and beer

(C) Nitrogen fixation in soil

(D) Treatment of sewage water

Correct Answer: (B)

Explanation: Pectinases are enzymes that break down pectin, a complex carbohydrate found in plant cell walls. Proteases break down proteins. In the food and beverage industry, pectinases are added to fruit pulp to break down pectin and increase juice yield. They also help clarify bottled fruit juices, beer, and wine by removing cloudiness (haze) caused by pectin and protein particles. This makes the drinks clearer, more visually appealing, and easier to filter. These enzymes are produced by microorganisms on an industrial scale.

Q25. Which of the following correctly describes the role of microbes in the nitrogen cycle?

(A) They convert nitrates in soil to atmospheric oxygen through decomposition

(B) They fix atmospheric nitrogen and also convert organic nitrogen back to atmospheric nitrogen through denitrification

(C) They absorb nitrogen from water and store it in plant tissues

(D) They only fix nitrogen; denitrification is carried out by plants

Correct Answer: (B)

Explanation: Microbes play a dual and essential role in the nitrogen cycle. On one hand, nitrogen-fixing bacteria (like Rhizobium, Azospirillum, and Anabaena) convert atmospheric nitrogen (N₂) into usable forms like ammonia (NH₃), making nitrogen available for plants. On the other hand, denitrifying bacteria (like Pseudomonas and Thiobacillus) convert nitrates (NO₃⁻) and nitrites (NO₂⁻) in the soil back into atmospheric nitrogen gas (N₂), completing the cycle. Without microbes, the nitrogen cycle would break down entirely, making life on Earth impossible.

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Q26. What is "Toddy," and which microorganism is responsible for its production?

(A) A fermented milk product produced by Lactobacillus

(B) A traditional fermented drink made from palm sap, fermented by naturally occurring yeast

(C) A cheese variety produced by Propionibacterium

(D) A vinegar variety produced by Acetobacter

Correct Answer: (B)

Explanation: Toddy (also called "neera" in its fresh form) is a traditional fermented alcoholic beverage popular in South and Southeast Asia, as well as parts of Africa. It is made from the sap of various palm trees, mainly coconut palm, date palm, or toddy palm. The naturally occurring yeast (mainly Saccharomyces species) present in the environment ferments the sugars in the palm sap, producing alcohol and carbon dioxide. Toddy is also used to ferment dosa and idli batter in South Indian cooking, contributing to the characteristic sour taste of these foods.

Q27. Which of the following statements about biocontrol is CORRECT?

(A) Biocontrol methods completely replace all other pest management approaches

(B) Biocontrol agents are chemical pesticides derived from natural sources

(C) Biocontrol uses natural predators, parasites, or pathogens to keep pest populations at manageable levels

(D) Biocontrol is only applicable to controlling weeds, not insects

Correct Answer: (C)

Explanation: Biological control (biocontrol) is an ecologically sustainable method of managing pests by using their natural enemies, including predators, parasites, parasitoids, and pathogens. For example, Bacillus thuringiensis kills insect larvae, Trichoderma controls soil fungi, Ladybird beetles eat aphids, and baculoviruses infect and kill specific pest insects. Biocontrol does not aim to eliminate pests entirely (which would be impractical and ecologically disruptive) but instead maintains pest populations at levels that do not cause economic damage; this is called pest management.

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Q28. Which of the following sets contains ONLY biofertilisers?

(A) Urea, Rhizobium, Azolla

(B) Rhizobium, Azospirillum, Mycorrhiza

(C) DAP, Mycorrhiza, Anabaena

(D) Nitrophosphate, Azolla, Trichoderma

Correct Answer: (B)

Explanation: Biofertilisers are living organisms (bacteria, fungi, or cyanobacteria) that enrich the nutritional quality of soil by fixing atmospheric nitrogen, solubilising phosphate, or improving nutrient uptake. Rhizobium (nitrogen-fixing symbiont in legume roots), Azospirillum (free-living nitrogen fixer for cereals), and Mycorrhiza (phosphate-solubilising fungal symbiont) are all genuine biofertilisers. Urea, DAP, and Nitrophosphate are chemical (synthetic) fertilisers, not biofertilisers. Trichoderma is primarily a biocontrol agent, not a biofertiliser.

Q29. Organic acids produced by microbes are used in several industries. Which of the following correctly matches the microorganism with its organic acid product?

(A) Aspergillus niger → Lactic acid

(B) Acetobacter aceti  → Citric acid

(C) Clostridium butylicum → Butyric acid

(D) Saccharomyces cerevisiae → Acetic acid

Correct Answer: (C)

Explanation: Several industrially important organic acids are produced by specific microorganisms. Clostridium butylicum produces butyric acid through anaerobic fermentation. Aspergillus niger (a fungus) is commercially used to produce citric acid (used in soft drinks and preserved foods). Acetobacter aceti  oxidises ethanol to produce acetic acid (vinegar). Lactobacillus produces lactic acid (used in dairy products and food preservation). Matching organisms with their products is a very common pattern in CUET and NEET questions.

Q30. What is the significance of microbes in energy production, and which gas produced by methanogens is used as fuel?

(A) Methanogens produce hydrogen gas, which is used directly as a cooking fuel

(B) Methanogens produce methane gas during anaerobic decomposition, which is used as biogas fuel

(C) Methanogens produce carbon dioxide, which drives turbines to generate electricity

(D) Methanogens produce ethanol from cellulose, which is used as a biofuel

Correct Answer: (B)

Explanation: Methanogens are anaerobic microorganisms (technically archaea) that decompose organic matter such as cattle dung, crop residues, food waste, and sewage sludge in the absence of oxygen to produce methane (CH₄) gas. This methane-rich mixture is called biogas. Biogas is a clean, renewable fuel used for cooking, lighting, and even electricity generation in rural India. The Indian government's National Biogas and Manure Management Programme (NBMMP) has promoted the installation of millions of biogas plants across the country. After biogas is extracted, the remaining slurry is a nutrient-rich organic manure used in fields.

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What is the CUET Biology Human Welfare Syllabus 2027?

Before practising questions, it's important to know what CUET actually asks from this chapter. Here's a clear topic-wise breakdown:

Topic	Sub-topics Covered
Microbes in Food Production	Curd (Lactobacillus), bread (Saccharomyces), cheese, vinegar, toddy
Microbes in Industrial Products	Antibiotics (Penicillin from Penicillium notatum), statins (Monascus purpureus), organic acids, ethanol
Microbes in Sewage Treatment	Primary treatment, secondary treatment, BOD, activated sludge, anaerobic sludge digesters
Microbes in Biogas Production	Methanogens, biogas composition (methane), biogas plants
Microbes as Biocontrol Agents	Bacillus thuringiensis (Bt toxin), baculoviruses, Trichoderma, Ladybird beetle, Dragonfly
Microbes as Biofertilisers	Rhizobium, Azospirillum, Azolla, Anabaena, Mycorrhiza

Covering all these topics using NCERT Class 12 Biology and the CUET Biology Important Topics guide will put you in an excellent position to score maximum marks.

What Should You Memorise for CUET Biology Human Welfare for 2027?

Here's a quick cheat sheet of organism-to-product pairs that are most frequently tested in CUET:

Product/Role	Microorganism
Curd	Lactobacillus
Swiss cheese holes	Propionibacterium shermanii
Bread (CO₂ for leavening)	Saccharomyces cerevisiae
Vinegar (Acetic acid)	Acetobacter aceti
Penicillin	Penicillium notatum
Streptomycin	Streptomyces griseus
Cyclosporin A	Trichoderma polysporum
Streptokinase	Streptococcus
Statins	Monascus purpureus
Citric acid	Aspergillus niger
Butyric acid	Clostridium butylicum
Biogas (Methane)	Methanogens
Nitrogen fixation (legumes)	Rhizobium
Nitrogen fixation (cereals)	Azospirillum
Nitrogen fixation (rice fields)	Azolla + Anabaena
Phosphorus absorption	Mycorrhiza
Biocontrol of insects	Bacillus thuringiensis (Bt)
Biocontrol of fungi	Trichoderma
Biocontrol of insects/arthropods	Baculoviruses

💡 Study Smart: Go through the CUET Biology Notes and revise this table before your exam. It can easily fetch you 4–5 marks!

How Many Questions is Expected from Human Welfare in CUET Biology 2027?

According to the CUET Biology exam pattern, CUET Biology consists of 50 questions in total, out of which students have to attempt 40. The Biology and Human Welfare chapter typically contributes 4 to 6 questions per year, making it one of the high-weightage topics you cannot afford to skip.

Since the questions from this chapter are largely factual and NCERT-based, consistent practice with the questions below can directly add 4–6 marks to your score.

How to Prepare for CUET Biology Human Welfare? What is the Best Strategy?

If you're wondering how to crack the Human Welfare questions in CUET Biology, here's a simple and effective plan:

1. Read NCERT First

The CUET Biology exam is almost entirely based on NCERT Class 12 Biology. Read Chapter 10 (Microbes in Human Welfare) and Chapter 8 (Human Health and Disease) thoroughly. 

2. Make Organism-Product Tables

The most common question pattern is "which organism produces which product." Make a table (like the one above) and revise it every day.

3. Understand the Process, Don't Just Memorise

For topics like sewage treatment and biogas production, understand the sequence of steps rather than just memorising names. Questions can be asked in a jumbled or application-based way.

4. Solve MCQs and Analyse Mistakes

After reading each topic, immediately solve MCQs. If you get a question wrong, go back to NCERT and find the exact line. This is the fastest way to improve accuracy.

5. Revise Regularly

Use the CUET Biology Question Papers to practise previous years' questions and track your improvement.

For a complete preparation roadmap, check out How to Prepare for CUET Biology.

Conclusion: Can You Score Full Marks in CUET Biology Human Welfare?

Yes, you absolutely can! Biology and Human Welfare is one of the most predictable and NCERT-close chapters in the entire CUET Biology syllabus. If you have carefully read the chapter, memorised the organism-product table, and practised the 30 MCQs given above with full understanding of the explanations, you are in a very strong position to score 4–6 full marks from this chapter alone.

Remember:

• Always read the full question carefully before answering
• Don't confuse Trichoderma (biocontrol agent AND source of Cyclosporin A)
• Know the difference between biofertilisers and chemical fertilisers
• Revise BOD and sewage treatment steps as a flow chart
• Use the CUET Biology Question Papers to simulate exam conditions

Keep practising, keep revising, and you'll crack CUET Biology with flying colours! All the best!