| Paper | Right | Wrong | Blank | Score | Percentage |
|---|
| 45-question paper | 39 | 6 | 0 | 150 / 180 | 83.3% |
| 60-question priority paper | 41 | 9 | 10 | 155 / 240 | 64.6% |
| Both papers | 80 | 15 | 10 | 305 / 420 | 72.6% |
Priority tiers on the 60-question paper
- Tier 1 — 24 right, 1 wrong, 0 blank out of 25.
- Tier 2 — 10 right, 3 wrong, 2 blank out of 15.
- Tier 3 — 6 right, 4 wrong, 5 blank out of 15.
- Tier 4 — 1 right, 1 wrong, 3 blank out of 5.
- Read that top line again: 24 of 25 priority-1 questions were correct, with no blanks. The marks that were lost sit almost entirely in the lower tiers.
The four things to fix
- Two facts were missed on both papers. The antibody H2L2 structure (answered 'two' twice) and the macrophage as the HIV factory (answered 'helper T-lymphocyte' twice). Repeated identical errors are the cheapest marks to recover.
- Assertion–reason: three of six wrong across the two papers. The errors run in both directions, so it is not a fixed bias but an unsteady procedure. Use the same three moves every time: mark A true or false, mark R true or false, then read 'A because R' aloud and judge only that.
- All ten blanks came from the scientists and years sections. Eight scientists and two years were skipped entirely. These are pure recall and cannot be reasoned out on the spot, so they need a memory card, not more practice.
- Reversal traps. Chemicals released during allergy versus drugs given for it; amoebiasis symptoms versus ascariasis symptoms; carrier versus vector. In each case both lists were known and the wrong one was chosen.
Common human diseases
Vector versus carrier, site of the sexual phase, and the two intestinal parasites • 4 cards
60Q Q24wrong3
GivenFertilisation and further development of Plasmodium take place in:
Your response(c) the liver of the human host→ Only asexual multiplication occurs in the liver.
Correct answer (b) the intestine of the female Anopheles mosquito
Concept to useSexual phase of the malarial parasite.
Rule / NCERT statementSexual reproduction occurs in the mosquito, which is therefore the definitive host; man is the intermediate host.
Baby steps
- Locate where gametes fuse.
- NCERT places fertilisation in the mosquito's intestine.
Why this option and not the others
| (a) | Salivary glands only store the sporozoites; no fusion occurs there. |
| (b) | Correct. The sporozoites formed there are then stored in the mosquito's salivary glands. |
| (c) | Only asexual multiplication occurs in the liver. |
| (d) | Asexual multiplication and gametocyte formation occur here, not fertilisation. |
ShortcutGut = site of fusion. Salivary gland = site of storage and delivery.
Where it went wrongChoosing salivary glands because they are the more memorable structure. Separate the site of an event from the site of storage.
60Q Q25wrong2
GivenIn amoebiasis, caused by Entamoeba histolytica in the large intestine, the housefly serves as:
Your response(b) a biological vector→ A biological vector supports development of the parasite; the housefly does not.
Correct answer (a) a mechanical carrier
Concept to useMechanical carrier versus biological vector.
Rule / NCERT statementHousefly → mechanical carrier (amoebiasis). Mosquito → biological vector (malaria, filariasis).
Baby steps
- Ask whether the parasite develops inside the insect.
- It does not → mechanical carrier.
Why this option and not the others
| (a) | Correct. It transfers parasites from the faeces of an infected person to food and food products; the parasite does not develop within it. |
| (b) | A biological vector supports development of the parasite; the housefly does not. |
| (c) | No sexual reproduction of the parasite occurs in the housefly. |
| (d) | The housefly is not a host at all in this life cycle. |
ShortcutInsect bites and parasite grows inside it → vector. Insect walks on food → carrier.
Where it went wrongCalling every transmitting insect a vector. NCERT uses the exact phrase 'mechanical carrier' here.
60Q Q26wrong3
GivenWhich set of symptoms belongs to amoebiasis?
Your response(a) Internal bleeding, muscular pain, anaemia and blockage of the intestinal passage→ These are the symptoms of ascariasis.
Correct answer (d) Constipation, abdominal pain and cramps, with stools containing excess mucous and blood clots
Concept to useSymptom sets of the parasitic intestinal diseases.
Rule / NCERT statementAmoebiasis: constipation, abdominal pain and cramps, stools with excess mucous and blood clots.
Baby steps
- Note the distinguishing detail: mucous and blood clots in the stool.
- That belongs to amoebiasis alone.
Why this option and not the others
| (a) | These are the symptoms of ascariasis. |
| (b) | That is malaria. |
| (c) | That is the common cold. |
| (d) | Correct. This is the symptom set NCERT gives for amoebic dysentery. |
ShortcutBlood and mucous in stool → amoebiasis. Blockage and anaemia → ascariasis.
Where it went wrongMerging the two intestinal parasites into one symptom list. Write them side by side and mark the differences.
45Q Q12wrong
GivenAssertion (A): Typhoid fever can be confirmed by the Widal test.
Reason (R): Salmonella typhi generally enters the small intestine through contaminated food and water and migrates to other organs through the blood.
Your response(a) Both A and R are true, and R is the correct explanation of A→ Rejected because the reason, though true, does not explain why the assertion holds.
Correct answer (b) Both A and R are true, but R is not the correct explanation of A
Concept to useTyphoid — pathogen, route and diagnosis.
Rule / NCERT statementBoth statements are individually true, but the route of entry does not explain why a serological test works.
Baby steps
- Check A: true — NCERT names Widal for typhoid.
- Check R: true — NCERT gives exactly this route of entry and spread.
- Ask whether R causes A. The Widal test works because the body makes antibodies against the bacterium, not because of its route of entry.
- So both true, R is not the explanation → option (b).
Why this option and not the others
| (a) | Rejected because the reason, though true, does not explain why the assertion holds. |
| (b) | Correct. Both statements are true, but the reason is an independent fact rather than the cause of the assertion. |
| (c) | Rejected because the reason is factually true. |
| (d) | Rejected because the assertion is factually true. |
ShortcutIn assertion–reason, first mark T/F for each part separately, then test only the causal link.
Where it went wrongThis is your recurring assertion–reason error: both parts are correctly judged true, but the causal link is then handled carelessly. Say the sentence aloud as 'A because R' — if it sounds wrong, choose option (b).
Immunity, antibodies and allergy
The antibody structure fact was lost on both papers — treat it as the first repair • 5 cards
45Q Q17wrong
GivenAn antibody molecule is represented as H2L2. The total number of polypeptide chains in one antibody molecule is:
Your response(a) Two — one heavy and one light chain→ That would be written HL, not H2L2. The subscript 2 applies to each chain type.
Correct answer (b) Four — two heavy and two light chains
Concept to useStructure of an antibody molecule.
Rule / NCERT statementH2L2: the subscript gives the number of chains of each type → 2 + 2 = 4.
Baby steps
- Read the subscript on H: 2 heavy chains.
- Read the subscript on L: 2 light chains.
- Total = 4 polypeptide chains.
Why this option and not the others
| (a) | That would be written HL, not H2L2. The subscript 2 applies to each chain type. |
| (b) | Correct. Each antibody has two identical light chains and two identical heavy chains, hence H2L2. |
| (c) | The formula shows equal numbers of heavy and light chains, two of each. |
| (d) | Asymmetric; the two arms of the Y-shaped molecule are identical. |
ShortcutTreat H2L2 exactly like a chemical formula — add the subscripts.
Where it went wrongReading H2L2 as 'one pair' and answering 2. Read the notation literally before reasoning.
60Q Q35wrong1
GivenThe number of polypeptide chains in one antibody molecule, represented as H2L2, is:
Your response(a) two→ That would correspond to the formula HL.
Correct answer (c) four
Concept to useStructure of the antibody molecule.
Rule / NCERT statementH2L2: two heavy chains + two light chains = four polypeptide chains.
Baby steps
- Read the subscripts literally.
- 2 + 2 = 4.
Why this option and not the others
| (a) | That would correspond to the formula HL. |
| (b) | The formula shows equal numbers of the two chain types, two of each. |
| (c) | Correct. Two identical heavy chains and two identical light chains. |
| (d) | Twice the number indicated by the formula. |
ShortcutTreat H2L2 like a chemical formula and simply add the subscripts.
Where it went wrongReading H2L2 as 'one pair' and answering two.
45Q Q16wrong
GivenThe secondary (anamnestic) response to a pathogen is highly intensified compared with the primary response because:
Your response(a) the pathogen becomes weaker after the first exposure→ The pathogen is unchanged; the change is in the host's immune system.
Correct answer (c) the body retains a memory of the first encounter through memory B and T cells
Concept to useAcquired immunity — primary and secondary responses.
Rule / NCERT statementAcquired immunity is pathogen-specific and memory-based.
Baby steps
- Identify the defining feature of acquired immunity — memory.
- Memory resides in B and T lymphocytes.
- Option (a) states this.
Why this option and not the others
| (a) | The pathogen is unchanged; the change is in the host's immune system. |
| (b) | Innate immunity is present from birth and acts on every exposure, non-specifically. |
| (c) | Correct. Memory cells respond faster and more strongly on subsequent exposure. |
| (d) | Circulating antibodies decline; it is the memory cells that persist and are re-activated. |
ShortcutMemory cells, not leftover antibodies, are what make the second response fast and large.
Where it went wrongExplaining the stronger response by leftover antibodies. This also explains why vaccination works — it plants memory cells.
45Q Q26wrong
GivenThe drugs used to reduce the symptoms of allergy quickly are:
Your response(a) Histamine, serotonin and interferon→ Histamine and serotonin cause the symptoms; giving them would worsen the allergy.
Correct answer (b) Antihistamine, adrenalin and steroids
Concept to useManagement of allergy.
Rule / NCERT statementAntihistamine, adrenalin and steroids → rapid relief of allergic symptoms.
Baby steps
- Identify the mediators of allergy.
- The treatment must oppose them → anti-histamine.
- Add adrenalin and steroids to complete the NCERT trio.
Why this option and not the others
| (a) | Histamine and serotonin cause the symptoms; giving them would worsen the allergy. |
| (b) | Correct. All three are named by NCERT as drugs that reduce allergy symptoms. |
| (c) | Antibiotics act on bacteria and have no role in allergy. |
| (d) | These are used in the management of AIDS. |
ShortcutThe antidote carries the prefix: histamine causes it, antihistamine cures it.
Where it went wrongThis is the mirror image of the previous question. NEET often asks both versions in the same paper; keep the two lists physically separate in your notes.
45Q Q20wrong
GivenAssertion (A): The immunity that a foetus receives from its mother through the placenta is called passive immunity.
Reason (R): Ready-made antibodies are transferred to the foetus, whose own immune system is not stimulated to produce them.
Your response(d) A is false but R is true→ Rejected because the assertion is factually true.
Correct answer (a) Both A and R are true, and R is the correct explanation of A
Concept to useNatural passive immunity.
Rule / NCERT statementPassive immunity = transfer of ready-made antibodies; source can be natural (placenta, colostrum) or artificial (antivenom).
Baby steps
- Check A: true — NCERT calls this passive immunity.
- Check R: true — the defining feature of passive immunity.
- Ask whether R explains A: yes, it is precisely the definition being applied.
- Both true and R explains A → option (a).
Why this option and not the others
| (a) | Correct. Both statements are factually true and the reason supplies the mechanism behind the assertion. |
| (b) | Rejected because the reason does explain the assertion here. |
| (c) | Rejected because the reason is factually true. |
| (d) | Rejected because the assertion is factually true. |
ShortcutWhen the reason is the definition of the term used in the assertion, the answer is almost always option (a).
Where it went wrongDenying the causal link out of over-caution. Here the reason is the definition itself, so the link is direct.
AIDS and cancer
The macrophage-versus-helper-T confusion also cost marks twice • 3 cards
45Q Q31wrong
GivenAfter entering the body, HIV first replicates inside which cell, which then behaves as an 'HIV factory'?
Your response(b) Helper T-lymphocyte→ Helper T-cells are attacked subsequently; their progressive decrease is what causes the immunodeficiency, but they are not called the factory.
Correct answer (a) Macrophage
Concept to useSequence of events in HIV infection.
Rule / NCERT statementMacrophage = HIV factory (survives and releases virus). Helper T-cells = destroyed progressively → immunodeficiency.
Baby steps
- Separate the two cell types by role.
- Factory → macrophage.
- Victim (count falls) → helper T-lymphocyte.
Why this option and not the others
| (a) | Correct. The virus enters macrophages and replicates there while the macrophage continues to survive, releasing virus particles continuously. |
| (b) | Helper T-cells are attacked subsequently; their progressive decrease is what causes the immunodeficiency, but they are not called the factory. |
| (c) | B-cells produce antibodies and are not the primary replication site of HIV. |
| (d) | Mature red blood cells have no nucleus and cannot support viral replication. |
ShortcutMacrophage makes the virus; helper T-cell is murdered by it. Two different cells, two different verbs.
Where it went wrongAnswering 'helper T-cell' because it is the fact most associated with AIDS. The stem asked for the replication site, not the cell that declines.
60Q Q44wrong2
GivenAfter entering the body, HIV first replicates inside a cell that survives and continues to release virus particles, acting as an 'HIV factory'. That cell is the:
Your response(a) helper T-lymphocyte→ Helper T-cells are attacked subsequently and their numbers fall progressively, causing immunodeficiency.
Correct answer (c) macrophage
Concept to useSequence of events in HIV infection.
Rule / NCERT statementMacrophage = HIV factory. Helper T-lymphocytes = progressively destroyed, leading to immunodeficiency.
Baby steps
- Separate the two cell types by their role.
- Factory → macrophage; victim → helper T-cell.
Why this option and not the others
| (a) | Helper T-cells are attacked subsequently and their numbers fall progressively, causing immunodeficiency. |
| (b) | B-cells produce antibodies and are not the primary replication site. |
| (c) | Correct. The macrophage survives while producing virus particles continuously. |
| (d) | NK cells belong to the cellular barrier of innate immunity and are not the described site. |
ShortcutThe macrophage makes the virus; the helper T-cell is killed by it.
Where it went wrongAnswering 'helper T-cell' because it is the fact most associated with AIDS. The stem asks for the replication site.
60Q Q53wrong3
GivenAssertion (A): Tumour cells are given α-interferon as part of immunotherapy.
Reason (R): Cancer cells are able to avoid detection and destruction by the patient's immune system.
Your response(b) Both A and R are true, but R is not the correct explanation of A→ Rejected because the reason does explain the assertion here.
Correct answer (a) Both A and R are true, and R is the correct explanation of A
Concept to useImmunotherapy in cancer.
Rule / NCERT statementTumour cells largely escape immune detection, so patients are given biological response modifiers such as α-interferon, which activate the immune system.
Baby steps
- Check A: true — α-interferon is used in cancer treatment.
- Check R: true — NCERT states that cancer cells escape immune detection.
- Ask whether R explains A: the escape from immune surveillance is precisely why the immune system must be boosted.
- Both true and R explains A.
Why this option and not the others
| (a) | Correct. Both statements are factually true and the reason supplies the mechanism behind the assertion. |
| (b) | Rejected because the reason does explain the assertion here. |
| (c) | Rejected because the reason is factually true. |
| (d) | Rejected because the assertion is factually true. |
ShortcutIf the reason states the problem that the assertion's action is designed to solve, the link is genuine.
Where it went wrongYour recurring assertion–reason error: judging both parts true and then denying the link. Test it as 'A because R' and see whether the sentence stands.
Drugs, alcohol and adolescence
Both misses came from the last two pages of the chapter • 2 cards
60Q Q14wrong2
GivenAccording to NCERT, adolescence covers the period between the ages of:
Your response(c) 13 and 19 years→ The everyday definition of 'teenage', but not the NCERT figure.
Correct answer (d) 12 and 18 years
Concept to useAdolescence and vulnerability to substance abuse.
Rule / NCERT statementAdolescence = 12–18 years; a period of major biological and behavioural change.
Baby steps
- Recall the numeric range attached to adolescence in the drug abuse section.
- It is 12 to 18 years.
Why this option and not the others
| (a) | Not the range given in the text. |
| (b) | Not the range given in the text. |
| (c) | The everyday definition of 'teenage', but not the NCERT figure. |
| (d) | Correct. This is the bridge between childhood and adulthood and the period of greatest vulnerability to drug and alcohol abuse. |
ShortcutDo not answer with the word 'teenage' (13–19). NCERT says 12–18.
Where it went wrongSubstituting common sense for the printed figure. The distractor 13–19 exists precisely to catch that.
60Q Q60wrong3
GivenWhich of the following is recommended by NCERT for the prevention and control of drug and alcohol abuse among adolescents?
Your response(c) Withholding information about drugs so that curiosity is not aroused→ NCERT emphasises education and counselling rather than concealment.
Correct answer (b) Avoiding undue peer pressure, seeking help from parents and peers, and looking for danger signs
Concept to usePrevention and control of adolescent substance abuse.
Rule / NCERT statementAvoid undue peer pressure; education and counselling; seeking help from parents and peers; looking for danger signs; seeking professional and medical help.
Baby steps
- Recall the five-point list from the end of the chapter.
- Only the first option reproduces items from it.
Why this option and not the others
| (a) | Isolation is not recommended; support and counselling are. |
| (b) | Correct. Education and counselling, along with professional and medical help, complete the list. |
| (c) | NCERT emphasises education and counselling rather than concealment. |
| (d) | Nothing of this kind appears in the text. |
ShortcutFive measures, all built on support rather than punishment. This is easy to skip and easy to be asked.
Where it went wrongDismissing the last section of the chapter as non-examinable prose. Statement-based questions are regularly set from it.
Scientists and years — the questions left blank
Ten blanks, every one of them from these two sections • 11 cards
60Q Q02not attempted2
GivenThe scientist who developed the first vaccine, using material from cowpox lesions to protect against smallpox, was:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (d) Edward Jenner
Concept to useHistory of vaccination.
Rule / NCERT statementEdward Jenner, 1796 — cowpox material used against smallpox; origin of the word 'vaccine' (vacca = cow).
Baby steps
- Link the disease to the scientist: smallpox → Jenner.
- Confirm with the etymology clue: vaccine ← vacca ← cow ← cowpox.
Why this option and not the others
| (a) | Pasteur developed later attenuated vaccines, notably against rabies, but not the first smallpox vaccine. |
| (b) | Koch is remembered for isolating disease-causing bacteria and for his postulates, not for the smallpox vaccine. |
| (c) | Ross worked on the transmission of malaria. |
| (d) | Correct. Jenner used cowpox material in 1796; the word 'vaccine' itself comes from the Latin vacca, meaning cow. |
ShortcutCow → vacca → vaccine → Jenner. The word itself carries the answer.
Where it went wrongInterchanging Jenner and Pasteur. Jenner = smallpox and the first vaccine; Pasteur = rabies and the attenuation principle.
60Q Q03not attempted2
GivenWorking in India, this scientist demonstrated that the malarial parasite is transmitted by the mosquito, and received the Nobel Prize in 1902:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (c) Ronald Ross
Concept to useDiscovery of the mode of transmission of malaria.
Rule / NCERT statementRonald Ross — malarial parasite in the mosquito, proving vector transmission; Nobel Prize 1902.
Baby steps
- Separate 'who found the parasite' from 'who found how it spreads'.
- Transmission by mosquito → Ronald Ross.
Why this option and not the others
| (a) | Laveran discovered the parasite itself in human blood; he did not establish mosquito transmission. |
| (b) | Koch worked on tuberculosis and cholera bacteria. |
| (c) | Correct. Ross showed the malarial parasite developing in the mosquito, establishing mosquito transmission of malaria. |
| (d) | Metchnikoff is associated with phagocytosis. |
ShortcutRoss → Route of transmission. Laveran → Located the parasite.
Where it went wrongSwapping Ross and Laveran. Fix them by what each one found: the vector, or the parasite.
60Q Q04not attempted3
GivenKoch's postulates, together with the discovery of the bacteria causing tuberculosis and cholera, are credited to:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (b) Robert Koch
Concept to useEstablishing that a specific microbe causes a specific disease.
Rule / NCERT statementRobert Koch — Mycobacterium tuberculosis, Vibrio cholerae, and Koch's postulates.
Baby steps
- Identify the idea being tested: proving causation, not treatment.
- That framework is Koch's.
Why this option and not the others
| (a) | Pasteur established the germ theory and attenuated vaccines but did not frame these postulates. |
| (b) | Correct. Koch isolated Mycobacterium tuberculosis and Vibrio cholerae and framed the postulates that link a specific microbe to a specific disease. |
| (c) | Jenner's contribution was the smallpox vaccine. |
| (d) | von Behring's contribution was serum therapy using antitoxins. |
ShortcutKoch = the rule-maker (postulates). Pasteur = the vaccine-maker. Jenner = the first vaccine.
Where it went wrongTreating all nineteenth-century microbiologists as interchangeable. Attach one signature contribution to each name.
60Q Q05not attempted3
GivenThe principle of using weakened (attenuated) pathogens to produce a vaccine, applied famously to rabies, was established by:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (a) Louis Pasteur
Concept to useAttenuation as the basis of vaccine preparation.
Rule / NCERT statementLouis Pasteur — rabies vaccine; weakened pathogens retain antigenicity but lose virulence.
Baby steps
- Note the key word 'attenuated'.
- Attenuation as a designed method belongs to Pasteur.
Why this option and not the others
| (a) | Correct. Pasteur developed the rabies vaccine and established attenuation as a general principle of vaccine preparation. |
| (b) | Jenner used a naturally related virus (cowpox), not a deliberately weakened pathogen. |
| (c) | Rous is remembered for a cancer-causing virus. |
| (d) | Porter worked on the chemical structure of antibodies. |
ShortcutJenner borrowed a milder relative of the virus; Pasteur weakened the virus itself.
Where it went wrongBelieving Jenner and Pasteur used the same method. The distinction between a related organism and an attenuated one is exactly what gets asked.
60Q Q06not attempted4
GivenThe malarial parasite was first observed in the blood of a malaria patient by:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (d) Charles Louis Alphonse Laveran
Concept to useDiscovery of Plasmodium.
Rule / NCERT statementLaveran (1880) — parasite seen in patient's blood. Ross (1897) — parasite traced to the mosquito.
Baby steps
- Order the two discoveries in time: the parasite must be found before its vector.
- The earlier one is Laveran's.
Why this option and not the others
| (a) | Ross established the role of the mosquito in transmission, after the parasite was already known. |
| (b) | Koch worked with bacteria, not with the malarial protozoan. |
| (c) | Pasteur's work was on fermentation, germ theory and vaccines. |
| (d) | Correct. Laveran first saw the parasite in human blood in 1880 and received the Nobel Prize in 1907. |
ShortcutParasite first, vector second: Laveran then Ross.
Where it went wrongThis is enrichment beyond the NCERT text. Know it for elimination, but never at the cost of the NCERT disease table.
60Q Q07not attempted4
GivenThe engulfing and destruction of microbes by certain white blood cells — the basis of the cellular barrier of innate immunity — was first described by:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (c) Elie Metchnikoff
Concept to useOrigin of the idea of cellular immunity.
Rule / NCERT statementMetchnikoff → phagocytosis → the cellular barrier (macrophages, monocytes, neutrophils, natural killer cells).
Baby steps
- Match the mechanism to the person: eating microbes → phagocytosis → Metchnikoff.
Why this option and not the others
| (a) | von Behring worked on antitoxins in serum, that is, on humoral rather than cellular defence. |
| (b) | Jenner's work preceded any cellular explanation of immunity. |
| (c) | Correct. Metchnikoff described phagocytosis and shared the Nobel Prize in 1908. |
| (d) | Edelman worked on antibody structure. |
ShortcutMetchnikoff = cells eat microbes. von Behring = serum neutralises toxins.
Where it went wrongEnrichment item. Its real value is that it fixes the difference between cellular and humoral defence in your mind.
60Q Q08not attempted3
GivenPassive immunisation, in which ready-made antibodies are given to a patient, traces back to the serum-therapy work of:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (b) Emil von Behring
Concept to useHistorical basis of passive immunisation.
Rule / NCERT statementvon Behring — antitoxin serum → the ancestor of today's antivenom and anti-tetanus preparations.
Baby steps
- Identify the type of immunity: ready-made antibodies → passive.
- The serum-therapy name is von Behring.
Why this option and not the others
| (a) | Koch identified pathogens; he did not introduce serum therapy. |
| (b) | Correct. His antitoxin serum against diphtheria was the first therapeutic use of ready-made antibodies; he received the first Nobel Prize in Physiology or Medicine in 1901. |
| (c) | Ross worked on malaria transmission. |
| (d) | Pasteur's vaccines produce active, not passive, immunity. |
ShortcutSerum carries antibodies → passive. Vaccine trains the body → active.
Where it went wrongPlacing every immunisation discovery under Pasteur. Vaccines are active; serum is passive.
60Q Q09not attempted4
GivenThe virus responsible for AIDS was isolated in 1983 by a team that included:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (a) Luc Montagnier and Françoise Barré-Sinoussi
Concept to useDiscovery of HIV.
Rule / NCERT statementAIDS first reported 1981; HIV isolated 1983; Nobel Prize 2008.
Baby steps
- Place the event in time: AIDS was reported in 1981, so its virus was found soon after.
- Only one option contains twentieth-century virologists of that period.
Why this option and not the others
| (a) | Correct. Their isolation of HIV was recognised with the Nobel Prize in 2008. |
| (b) | Both had died long before HIV was known. |
| (c) | They worked on antibody structure. |
| (d) | Rous worked on a cancer-causing virus and Jenner on smallpox. |
Shortcut1981 reported → 1983 virus isolated. Two years apart; keep the pair together.
Where it went wrongEnrichment item. Even if the names are unfamiliar, the dates let you eliminate every other option.
60Q Q16not attempted3
GivenThe definition of health as a state of complete physical, mental and social well-being, and not merely the absence of disease, was given by the World Health Organization, established in:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (b) 1948
Concept to useModern definition of health.
Rule / NCERT statementHealth is not merely the absence of disease; it includes physical, mental and social well-being.
Baby steps
- Recall the founding year of the WHO: 1948.
- Note that 1980 in the options belongs to smallpox eradication, a different fact.
Why this option and not the others
| (a) | Too early; this precedes the founding of the United Nations system. |
| (b) | Correct. The WHO was established in 1948, and World Health Day is observed on 7 April. |
| (c) | Ten years too late. |
| (d) | That is the year smallpox eradication was declared. |
Shortcut1948 WHO founded → 1980 smallpox eradicated. Two dates, two events, often swapped.
Where it went wrongMarking 1980 because it is the more familiar year in this chapter. Read what the question is actually dating.
60Q Q17not attempted3
GivenThe disease declared globally eradicated in 1980, entirely through vaccination, is:
Your responseLeft blank. A blank scores zero; an eliminated guess on a four-option question has an expected value above zero.
Correct answer (a) Smallpox
Concept to useAchievements of immunisation programmes.
Rule / NCERT statementSmallpox — eradicated. Polio — controlled by mass immunisation (pulse polio programme).
Baby steps
- Ask which disease no longer occurs anywhere.
- Only smallpox qualifies.
Why this option and not the others
| (a) | Correct. Smallpox is the standard example of a disease eliminated by a worldwide immunisation programme. |
| (b) | Polio has been targeted by mass immunisation such as the pulse polio programme, but it was not declared eradicated in 1980. |
| (c) | Malaria remains widespread and there is no eradication declaration. |
| (d) | Tuberculosis continues to be a major public health problem. |
ShortcutEradicated means gone from the planet. Only smallpox has earned that word in this chapter.
Where it went wrongTreating polio as eradicated because of the familiarity of the pulse polio campaign. Controlled is not the same as eradicated.
60Q Q10wrong4
GivenThe H2L2 chemical structure of the antibody molecule was worked out by:
Your response(c) Edward Jenner and Louis Pasteur→ Both worked on vaccines, well before protein structures could be determined.
Correct answer (d) Rodney Porter and Gerald Edelman
Concept to useStructure of the antibody molecule.
Rule / NCERT statementAntibody = 2 heavy + 2 light polypeptide chains, written H2L2.
Baby steps
- Recall that the structure is a protein-chemistry result.
- That points to twentieth-century protein chemists, not to the vaccine pioneers.
Why this option and not the others
| (a) | Their contributions were phagocytosis and early immunochemical theory, not the chain structure. |
| (b) | Both worked on malaria. |
| (c) | Both worked on vaccines, well before protein structures could be determined. |
| (d) | Correct. Their work on antibody structure earned the Nobel Prize in 1972. |
ShortcutEven if the names slip, the structure must not: H2L2 = 4 chains.
Where it went wrongEnrichment item. The structure itself is a priority-1 fact; the names are not.
What to do before the next paper
- Write the antibody structure and the HIV cell sequence on one card and revise it daily until the next test. Two repeated errors are worth eight marks.
- Do the six assertion–reason items in these two papers again, on paper, writing T or F beside A and R before looking at the options.
- Make one card of scientists and one of years and numbers. Ten blanks at four marks each is forty marks sitting untouched.
- Keep the blank rate at zero on priority-1 and priority-2 questions, which it already was. That habit is working.