• Keneitsino Lydia
• June 6, 2026

Essential Vaccines and Drug Abuse MCQs Class 12 Biology – Powerful Exam Practice Questions

Vaccines and Drug Abuse MCQs Class 12 Biology is an important revision topic for aspirants who want to understand two major areas of human health: disease prevention and the harmful effects of substance abuse. Vaccines and Drug Abuse MCQs Class 12 Biology helps aspirants connect immunity, antibodies, memory cells, vaccination programmes, addictive substances, plant-derived drugs, and public health awareness in one exam-focused chapter. In Class 12 Biology, vaccines explain how the body prepares itself against pathogens, while drug abuse explains how certain substances disturb the nervous system, damage organs, and affect behaviour. Vaccines and Drug Abuse MCQs Class 12 Biology is useful because both areas are frequently asked in board exams, NEET, nursing entrance exams, and other biology-based competitive tests.

Vaccines and Drug Abuse MCQs Class 12 Biology becomes easier when aspirants first understand vaccination. A vaccine is a biological preparation that stimulates the immune system to produce protection against a specific disease. Vaccines and Drug Abuse MCQs Class 12 Biology teaches that vaccines may contain weakened organisms, killed organisms, toxoids, purified antigens, recombinant proteins, or other antigenic components. When a vaccine enters the body, immune cells recognize the antigen and activate B-lymphocytes and T-lymphocytes. Vaccines and Drug Abuse MCQs Class 12 Biology helps aspirants understand that antibodies and memory cells are formed, allowing the immune system to respond faster if the real pathogen enters later.

Vaccines and Drug Abuse MCQs Class 12 Biology also explains active and passive immunity. Active immunity develops when the body produces its own antibodies after infection or vaccination. Passive immunity occurs when ready-made antibodies are transferred, such as from mother to child through the placenta or colostrum, or through antiserum after snake bite or rabies exposure. Vaccines and Drug Abuse MCQs Class 12 Biology helps aspirants remember that active immunity is usually long-lasting, while passive immunity gives quick but temporary protection. Vaccines and Drug Abuse MCQs Class 12 Biology also covers important examples such as BCG for tuberculosis, DPT for diphtheria, pertussis, and tetanus, hepatitis B vaccine, influenza vaccine, and pulse polio immunization.

Vaccines and Drug Abuse MCQs Class 12 Biology is equally important for understanding drug abuse. Drug abuse refers to the harmful and repeated use of substances that affect the body and mind. Vaccines and Drug Abuse MCQs Class 12 Biology helps aspirants revise drugs such as alcohol, tobacco, cannabis, cocaine, morphine, heroin, LSD, barbiturates, amphetamines, and sedatives. Many drugs act on the nervous system by changing neurotransmitter activity, producing euphoria, hallucinations, relaxation, dependence, or altered perception. Vaccines and Drug Abuse MCQs Class 12 Biology is useful because exam questions often ask about drug sources, effects, categories, and harmful consequences.

Aspirants studying Vaccines and Drug Abuse MCQs Class 12 Biology should focus on common plant sources of drugs. Morphine is obtained from Papaver somniferum, heroin is diacetylmorphine derived from morphine, cocaine is obtained from Erythroxylum coca, and cannabinoids are obtained from Cannabis plants. Vaccines and Drug Abuse MCQs Class 12 Biology also helps aspirants remember that LSD is associated with Claviceps, while reserpine is obtained from Rauwolfia serpentina. These source-based facts are important because they are often tested directly. Vaccines and Drug Abuse MCQs Class 12 Biology becomes more manageable when aspirants prepare a table for drug name, plant source, category, effect, and risk.

Vaccines and Drug Abuse MCQs Class 12 Biology also builds awareness about addiction, tolerance, dependence, and withdrawal. Tolerance occurs when a person needs a higher dose to get the same effect. Dependence develops when the body or mind starts relying on the substance. Vaccines and Drug Abuse MCQs Class 12 Biology reminds aspirants that drug abuse may lead to liver damage, nervous system problems, respiratory issues, cancer risk, poor judgement, social difficulties, and long-term health decline. Tobacco smoke contains harmful substances such as tar, carbon monoxide, and carcinogenic compounds, while excess alcohol intake may damage the liver and lead to cirrhosis.

For effective revision, Vaccines and Drug Abuse MCQs Class 12 Biology should be studied through comparison charts, concept maps, and short notes. Aspirants can divide the topic into two sections: vaccination and immunization on one side, and drug abuse and addiction on the other side. Vaccines and Drug Abuse MCQs Class 12 Biology becomes easier when aspirants connect vaccines with immunity and drug abuse with harmful nervous system effects. Aspirants should revise terms such as antigen, antibody, memory cell, active immunity, passive immunity, toxoid, attenuated vaccine, addiction, withdrawal, tolerance, hallucinogen, opioid, stimulant, and depressant.

Vaccines and Drug Abuse MCQs Class 12 Biology:

1. What is the study of organisms with their environment called?

A. Ecology
B. Cytology
C. Gene ecology
D. None of these

Answer: A. Ecology

Explanation: Ecology is the branch of biology that deals with the inter-relationships among organisms and the interaction between organisms and their environment.

2. What is a keystone species?

A. A species which adds up to only a small proportion of the total biomass of a community, yet has a huge impact on the community’s organization and survival
B. A common species that has plenty of biomass, yet has a fairly low impact on the community’s organization
C. A rare species that has minimal impact on the biomass and on other species in the community
D. A dominant species that constitutes a large proportion of the biomass and which affects many other species

Answer: A. A species which adds up to only a small proportion of the total biomass of a community, yet has a huge impact on the community’s organization and survival

Explanation: A keystone species may form only a small proportion of the total biomass of a community, but it has a major influence on community organization and survival.

3. What is the soil transported by wind known as?

A. Colluvial
B. Aeolian
C. Alluvial
D. Glacial soil

Answer: B. Aeolian

Explanation: Aeolian soil, also called wind-blown soil, is soil transported or deposited by the action of wind.

4. Where are air spaces present?

A. Hydrophytes
B. Xerophytes
C. Mesophytes
D. All of these

Answer: A. Hydrophytes

Explanation: Air spaces are commonly present in hydrophytes, which are plants growing in water or very wet habitats.

5. How is the relation between species richness and area described on a logarithmic scale?

A. log S = log C – Z log A
B. log S = Z log A
C. log S = log C + Z log A
D. log S = log C

Answer: C. log S = log C + Z log A

Explanation: On a logarithmic scale, the species-area relationship is represented as log S = log C + Z log A.

6. What are ecotypes?

A. Only morphologically different
B. Only genetically different
C. Both A and B
D. Both morphologically and genetically similar

Answer: C. Both A and B

Explanation: Ecotypes are populations of a species that show both morphological and genetic differences due to adaptation to different environmental conditions.

7. What is the cultivation of plants without the use of soil called?

A. Aquaculture
B. Urban farming
C. Sericulture
D. Hydroponics

Answer: D. Hydroponics

Explanation: Hydroponics is the cultivation of plants without soil, usually by using nutrient-rich water solutions.

8. Microtubule depolymerizing drug such as colchicine is expected to

A. Inhibit spindle formation during mitosis
B. Inhibit cytokinesis
C. Allow mitosis beyond metaphase
D. Induce formation of multiple contractile rings

Answer: A. Inhibit spindle formation during mitosis

Explanation: Colchicine inhibits spindle formation during mitosis by interfering with microtubules, preventing chromosome separation.

9. Papaver somniferum is cultivated to obtain drugs. Morphine is obtained from its latex.

A. Both A and R are correct and R is the correct explanation of A
B. Both A and R are correct and R is not the correct explanation of A
C. A is correct but R is wrong
D. A is wrong but R is correct

Answer: A. Both A and R are correct and R is the correct explanation of A

Explanation: Papaver somniferum, also called opium poppy, is cultivated to obtain drugs such as opium, morphine, codeine, and heroin from its milky latex.

10. Identify the given diagram and its effect.

A. Cannabinoid – Effects cardiovascular function
B. Morphine – CNS depressant
C. Cocaine – Euphoria
D. Smack – Psychedelic effect

Answer: A. Cannabinoid – Effects cardiovascular function

Explanation: The given diagram represents a cannabinoid, which can affect cardiovascular function.

11. Cocaine is a stimulant, which may cause addiction. It is an alkaloid obtained from:

A. Eucalyptus
B. Erythroxylon
C. Rauwolfia
D. Papaver

Answer: B. Erythroxylon

Explanation: Cocaine is a stimulant alkaloid obtained from the coca plant, Erythroxylon coca.

12. Vinblastine is obtained from

A. Catharanthus roseus
B. Curcuma amada
C. Atropa belladonna
D. Syzygium cumini

Answer: A. Catharanthus roseus

Explanation: Vinblastine is obtained from Catharanthus roseus, also known as Madagascar periwinkle.

13. Women who consumed the drug thalidomide for relief from vomiting during early months of pregnancy gave birth to children with

A. No spleen
B. Hare-lip
C. Extra fingers and toes
D. Underdeveloped limbs

Answer: D. Underdeveloped limbs

Explanation: Thalidomide use during early pregnancy was associated with birth defects such as underdeveloped limbs.

14. Nicotine acts as a stimulant because it mimics the effect of

A. Testosterone
B. Dopamine
C. Thyroxine
D. Acetylcholine

Answer: D. Acetylcholine

Explanation: Nicotine acts as a stimulant because it mimics acetylcholine, a neurotransmitter.

15. In the stratosphere, which of the following elements acts as a catalyst in the degradation of ozone and release of molecular oxygen?

A. Carbon
B. Cl
C. Oxygen
D. Fe

Answer: B. Cl

Explanation: Chlorine acts as a catalyst in the degradation of ozone in the stratosphere, leading to the release of molecular oxygen.

16. Synecology refers to _______.

A. Ecological study of individual species
B. Study of ecological communities
C. Plant ecology
D. Physiological ecology

Answer: B. Study of ecological communities

Explanation: Synecology is the ecological study of communities and the interactions among different species.

17. Plants growing in acidic soil are termed as:

A. Halophytes
B. Oxalophytes
C. Acidophytes
D. Hydrophytes

Answer: C. Acidophytes

Explanation: Plants growing in acidic soil are called acidophytes.

18. Which of the following is important for speciation?

A. Seasonal isolation
B. Reproductive isolation
C. Behavioral isolation
D. Temporal isolation

Answer: B. Reproductive isolation

Explanation: Reproductive isolation prevents interbreeding between populations and plays an important role in the origin of new species.

19. Match the following:

A. Eurythermal
B. Euryhaline
C. Stenothermal
D. Stenohaline

I. Tolerate wide range of salinity
II. Tolerate narrow range of salinity
III. Corals
IV. Homeotherms

Options:

A. A-III, B-I, C-IV, D-II
B. A-III, B-II, C-IV, D-I
C. A-I, B-IV, C-III, D-II
D. A-IV, B-I, C-III, D-II

Answer: D. A-IV, B-I, C-III, D-II

Explanation: Eurythermal organisms tolerate a wide range of temperature and include homeotherms. Euryhaline organisms tolerate a wide range of salinity. Stenothermal organisms tolerate a narrow temperature range, such as corals. Stenohaline organisms tolerate a narrow range of salinity.

20. In ecotone, some species become abundant:

A. Sibling species
B. Endemic species
C. Rare species
D. Edge species

Answer: D. Edge species

Explanation: Species that are found primarily or most abundantly in an ecotone are called edge species.

21. The basic unit of study in Ecology is

A. Population
B. Organism
C. Community
D. Species

Answer: B. Organism

Explanation: The organism is considered the basic unit of study in ecology.

22. Different species residing in different geographical areas are:

A. Allopatric
B. Parapatric
C. Sympatric
D. None of these

Answer: A. Allopatric

Explanation: Allopatric species live in different geographical regions and are separated by spatial barriers.

23. Which of the following drugs is often given to patients after surgery as a pain killer?

A. Barbiturates
B. Morphine
C. Chewing tobacco
D. Cocaine

Answer: B. Morphine

Explanation: Morphine is a narcotic drug used as a sedative and painkiller, often given to patients after surgery.

24. Which of the following is not a mode of tobacco abuse?

A. It is smoked
B. Chewed as Gutkha
C. Used in the form of snuff
D. It is taken by injection

Answer: D. It is taken by injection

Explanation: Tobacco may be smoked, chewed, or used as snuff, but it is not abused by injection.

25. The use of prohibited drugs by athletes with the intention of improving athletic performance is called _____.

A. Doping
B. Addiction
C. Drug dependence
D. Dipsomania

Answer: A. Doping

Explanation: The use of prohibited drugs by athletes to improve performance is called doping.

26. What is a vaccine?

A. Treated bacteria, virus and protein
B. Treated algae
C. Treated fungi
D. Treated plasmodium

Answer: A. Treated bacteria, virus and protein

Explanation: A vaccine is a biological preparation that stimulates immunity against a disease. It may contain treated or weakened bacteria, viruses, proteins, or antigens.

27. Which one of the following is a correct match?

A. Reserpine – Tranquilizer
B. Cocaine – Opiatic narcotic
C. Morphine – Hallucinogenic
D. Bhang – Analgesic

Answer: A. Reserpine – Tranquilizer

Explanation: Reserpine is an alkaloid extracted from Rauwolfia serpentina and is used as a tranquilizer.

28. The transport of which neurotransmitter is interfered by cocaine?

A. Acetylcholine
B. Serotonin
C. GABA
D. Dopamine

Answer: D. Dopamine

Explanation: Cocaine interferes with dopamine transport, increasing dopamine levels and producing stimulant effects.

29. Every time when the dosage of a drug has to be increased to achieve the same “kick” that initially occurred in response to a smaller dose, this condition is known as ______.

A. Tolerance
B. Rebound effect
C. Addiction
D. Withdrawal symptoms

Answer: A. Tolerance

Explanation: Tolerance occurs when repeated drug use reduces the body’s response, requiring higher doses to produce the same effect.

 

 

Conclusion on Vaccines and Drug Abuse MCQs Class 12 Biology

In conclusion, Vaccines and Drug Abuse MCQs Class 12 Biology is a valuable topic for aspirants who want to master human health concepts in a structured and exam-ready way. Vaccines and Drug Abuse MCQs Class 12 Biology improves understanding of immune protection, vaccination programmes, antibody response, drug categories, addiction, dependence, and health risks. Vaccines and Drug Abuse MCQs Class 12 Biology also helps aspirants connect textbook facts with real-life health awareness. With regular revision, this topic can help aspirants answer biology questions with better accuracy, speed, and confidence.