Exams › NEET › Biology › Human Health and Disease
224 questions with worked solutions.
Q1. Diarrhea through food can be avoided by
Answer: Refrigerating the food
Refrigeration slows the growth of bacteria and other microbes that can contaminate food and cause diarrhea. Raw food and repeated thawing increase the risk of contamination and spoilage.
Q2. Renal rickets is related to old age
Answer: Chronic kidney disease
Renal rickets occurs when diseased kidneys cannot properly activate vitamin D or maintain normal calcium-phosphate balance, leading to defective bone mineralization. This is classically associated with chronic kidney disease.
Q3. Which is the drug used by health workers in the management of acute respiratory illness?
Answer: Co - trimoxazole
Co-trimoxazole is commonly used in the management of acute respiratory illness because it covers many typical bacterial causes seen in primary care. The other options are generally reserved for different infections or more severe situations.
Answer: (d) Salmonella typhi / Widal test
Typhoid fever is caused by Salmonella typhi. The Widal test detects antibodies against Salmonella antigens and is the standard confirmatory test among the options given.
Answer: (a) (iii) (iv) (i) (ii)
Typhoid is caused by Salmonella, pneumonia by Haemophilus, filariasis by Wuchereria, and malaria by Plasmodium. So the correct sequence is (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii).
Q6. The infectious stage of Plasmodium that enters the human body is
Answer: (a) Sporozoites
Sporozoites are the infective stage of Plasmodium for humans because they are injected into the bloodstream by an infected female Anopheles mosquito. Gametocytes are the forms taken up by the mosquito, while trophozoites develop later inside human red blood cells.
Q7. Which of the following pair is not correctly matched?
Answer: Syphilis - Trichuris trichura
Syphilis is caused by the bacterium Treponema pallidum, not Trichuris trichura. The other pairs are correctly matched with their known causative agents.
Q8. Which one of the following pairs of diseases both are caused by viruses?
Answer: Measles and rabies
Measles and rabies are both viral diseases: measles is caused by the measles virus, and rabies is caused by the rabies virus. The other options each include at least one disease caused by bacteria or a protozoan.
Q9. Which one of the following diseases is now considered nearly eradicated from India?
Answer: Small pox
Smallpox was eradicated globally and is considered nearly eradicated from India due to successful mass vaccination and surveillance. The other diseases listed still occur or have not been eradicated in the same way.
Answer: Mucus coating of epithelium lining the urogenital tract and the HCl in stomach - Physiological barriers
Mucus coating and stomach HCl are both physiological barriers because they create conditions that inhibit or destroy pathogens. The other options mismatch the examples with the wrong immunity category.
Q11. Which one of the following statements is correct with respect to immunity?
Answer: Preformed antibodies need to be injected to treat the bite by a viper snake.
A viper bite is treated with antivenom, which contains preformed antibodies that neutralize the venom immediately. This is passive immunity; the other options incorrectly assign antibody production, antibody structure, or graft rejection to the wrong cells.
Q12. Grafted kidney may be rejected in a patient due to:
Answer: Cell-mediated immune response
Graft rejection is classically a T-cell–mediated process, where recipient T cells recognize donor antigens and damage the transplanted kidney. This is the main mechanism of acute cellular rejection.
Q13. The cell-mediated immunity inside the human body is carried out by:
Answer: T-lymphocytes
Cell-mediated immunity is driven by T-lymphocytes, which recognize infected or abnormal cells and coordinate or directly execute immune responses. B-lymphocytes mainly produce antibodies, while thrombocytes and erythrocytes are not immune effector cells.
Answer: Tears
Tears act as a physiological barrier because they continuously flush the eye surface and contain lysozyme, which can damage bacterial cell walls. This makes them an important first-line defense against microbial entry.
Answer: poisons released by living bacterial cells into the host tissue
Diphtheria symptoms are caused by an exotoxin produced and secreted by living Corynebacterium diphtheriae cells. This matches poisons released by living bacterial cells into host tissue, not toxins from dead cells or viruses.
Q16. Which one of the following is a viral disease of poultry?
Answer: New castle disease
Newcastle disease is caused by a virus and is a classic viral disease of poultry. Coryza, pasteurellosis, and salmonellosis are bacterial diseases, so they are not the correct choice.
Q17. A patient brought to a hospital with myocardial infarction is normally immediately given:
Answer: Streptokinase
Streptokinase is a thrombolytic agent used to dissolve the clot causing the myocardial infarction, restoring blood flow quickly. Penicillin treats bacterial infections, cyclosporin-A is an immunosuppressant, and statins are used for cholesterol lowering and prevention, not immediate clot lysis.
Q18. Which one of the sexually transmitted diseases is correctly matched with its pathogen?
Answer: Syphilis - Treponema pallidum
Syphilis is caused by the spirochete Treponema pallidum, so that pair is correct. The other options are mismatched because their pathogens do not cause those sexually transmitted diseases.
Q19. African sleeping sickness is due to:
Answer: Trypanosoma gambiense transmitted by Glossina palpalis
African sleeping sickness is caused by Trypanosoma gambiense, a protozoan transmitted by the tsetse fly (Glossina palpalis). The other options pair the wrong organism with the wrong vector or disease.
Q20. The causal organism for African sleeping sickness is:
Answer: T. gambiense
Trypanosoma gambiense is the classic cause of African sleeping sickness, especially the West African form. T. cruzi causes Chagas disease, while T. rhodesiense is associated with the East African form.