Biology and Human Welfare Syllabus NEET 2026

Biology plays an important role in improving human health, food production, sanitation, and environmental management. This unit explains how biological knowledge helps in the prevention of diseases, the development of medicines, the maintenance of health, and the use of microbes for human welfare.

This unit mainly focuses on human diseases caused by pathogens, immunity and vaccines, cancer, HIV/AIDS, drug and tobacco abuse, and beneficial uses of microbes in industries and agriculture. NEET questions from this chapter are factual and directly based on NCERT examples, diseases, microbes, and biological applications.

Human Health and Disease

Health is a state of complete physical, mental, and social well-being. Diseases disturb normal body functioning and may be infectious or non-infectious. Infectious diseases are caused by pathogens such as bacteria, viruses, fungi, protozoa, and worms.

Pathogens

Pathogens are disease-causing organisms that enter the body and affect normal physiological functions. They may spread through air, water, food, vectors, or direct contact.

Major types of Pathogens include:

• Bacteria

• Viruses

• Fungi

• Protozoa

• Helminths

Human Diseases

Several diseases in the NEET syllabus are caused by Pathogens and Parasites.

• Malaria is caused by Plasmodium and spreads through female Anopheles mosquito.

• Filariasis is caused by filarial worms and affects the lymphatic system.

• Ascariasis is caused by Ascaris through contaminated food and water.

• Typhoid is caused by Salmonella typhi and spreads through contaminated food.

• Pneumonia affects the lungs and is mainly bacterial.

• Common cold is caused by rhinoviruses.

• Amoebiasis is caused by Entamoeba histolytica.

• Ringworm is a fungal infection affecting skin and nails.

• Dengue and chikungunya are viral diseases spread by Aedes mosquitoes.

Immunity, Vaccines, Cancer, HIV and AIDS

The human body has natural defence mechanisms that protect against infections. This protective ability is called immunity.

Immunity and Vaccines

Immunity may be innate or acquired. Innate immunity is present from birth, while acquired immunity develops after infection or vaccination.

Vaccines contain weakened or dead pathogens that stimulate antibody production and provide protection against infectious diseases. Vaccination is important in preventing diseases such as polio, hepatitis, and smallpox.

Cancer

Cancer is the uncontrolled growth and division of abnormal cells in the body. It may occur due to genetic mutations, radiation, smoking, carcinogenic chemicals, or viral infections.

Common treatment methods include:

• Surgery

• Chemotherapy

• Radiotherapy

Early diagnosis is important for effective treatment.

HIV and AIDS

AIDS is caused by HIV (Human Immunodeficiency Virus), which attacks helper T-lymphocytes and weakens the immune system.

The virus spreads through:

• Unprotected sexual contact

• Infected blood transfusion

• Contaminated needles

• Mother-to-child transmission

Awareness and preventive measures are important in controlling HIV infection.

Adolescence, Drug Abuse and Tobacco Abuse

Adolescence is the stage between childhood and adulthood marked by physical, emotional, and hormonal changes. During this period, individuals may become vulnerable to drug, alcohol, and tobacco abuse.

Drug and Alcohol Abuse

Drug Abuse affects the nervous system and may lead to addiction, poor concentration, mental disorders, and social problems. Alcohol abuse damages organs such as the liver and heart.

Peer pressure and stress are common causes of substance abuse among adolescents.

Tobacco Abuse

Tobacco contains nicotine and several harmful carcinogens. Smoking and chewing tobacco increase the risk of lung cancer, bronchitis, and heart disease.

Awareness and counselling are important to prevent tobacco addiction.

Microbes in Human Welfare

Many microorganisms are useful in food production, industries, agriculture, and environmental management. Beneficial microbes help improve human welfare in several ways.

Microbes in Household Food Processing

Microbes are used in the preparation of curd, bread, cheese, and fermented foods.

Examples:

• Lactobacillus converts milk into curd

• Yeast is used in bread-making and fermentation

These microbes improve the taste and nutritional quality of food.

Microbes in Industrial Production

Industries use microbes for the commercial production of useful substances such as:

• Antibiotics

• Alcohol

• Organic acids

• Enzymes

Example:

• Penicillin is produced by the Penicillium fungus.

Microbes in Sewage Treatment and Energy Generation

Microorganisms help decompose organic matter during sewage treatment and reduce water pollution.

Methanogenic bacteria are used in biogas plants to produce methane-rich biogas, which serves as a renewable source of energy.

Microbes as Biocontrol Agents and Biofertilizers

Biocontrol agents help control pests biologically without using harmful chemicals.

Examples:

• Bacillus thuringiensis

• Ladybird beetles

Biofertilizers are microorganisms that naturally improve soil fertility.

Examples:

• Rhizobium

• Azotobacter

• Cyanobacteria

These microbes increase nutrient availability and support sustainable agriculture.

How to Prepare Biology and Human Welfare for NEET 2026

Biology and Human Welfare is an important NEET unit that includes human diseases, immunity, microbes, and biological applications in daily life. 

• Read NCERT thoroughly

Carefully study diseases, pathogens, microbial examples, immunity, and biological terms

• Practice Biology and Human Welfare NEET PYQs regularly

Solving Previous Year Questions helps in understanding that disease-based, assertion-reasoning, and factual questions are asked in NEET.

• Solve chapter-wise Biology and Human Welfare MCQs

Regular practice with PW MCQs improves retention of pathogens, vectors, microbial products, and disease symptoms.

• Use Biology and Human Welfare mind maps for revision

PW Mind maps help in quick revision of diseases, immunity, vaccines, microbes, sewage treatment, and biofertilizers before exams.

• Learn pathogens, vectors, and symptoms together

While studying diseases, memorise the causative organism, mode of transmission, vector, and major symptoms side by side for better retention.

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