31 Years NEET Previous Year Questions: Health & Disease - 1 - NEET MCQ

• Bacteria like Streptococcus pneumoniae and Haemophilus influenzae are responsible for the disease pneumonia in humans which infects the alveoli (air filled sacs) of the lungs.
• Entamoeba histolytica is a protozoan parasite in the large intestine of humans which causes amoebiasis (amoebic dysentery).
• Wuchereria (W. bancrofti and W. malayi), the filarial worms cause a slowly developing chronic inflammation of the organs in which they live for many years, usually the lymphatic vessels of the lower limbs and the disease is called elephantiasis or filariasis.
• Many fungi belonging to the genera Microsporum, Trichophyton and Epidermophyton are responsible for ringworms which is one of the most common infectious diseases in man, appearance of dry, scaly lesions on various parts of the body such as skin, nails and scalp are the main symptoms of the disease.

Hence, the correct option is D.

NCERT Reference: Topic “8.1 COMMON DISEASES IN HUMANS” of chapter 8 of NCERT.

• Active immunity is slow and takes time to give its full effective response.
• Foetus receiving some antibodies from their mother, through the placenta during pregnancy is an example of passive immunity.
• Active immunity is the immunity in which when a  host is exposed to antigens either living or dead, antibodies are produced in the host body.
• In passive immunity, readymade antibodies are directly given to protect the body against foreign agents.

Hence, the correct option is A.

Topic in NCERT: Active and Passive Immunity

Line in NCERT: "Active immunity is slow and takes time to give its full effective response."

• The infectious stage of Plasmodium that enters the human body is sporozoites that are formed as a result of sexual reproduction in the gut of the vector female Anopheles mosquito.
• These sporozoites then migrate to the salivary glands of the insect to infect the next human host.

Hence, the correct option is D.
NCERT Reference: Page no. 147 of topic “8.1 COMMON DISEASES IN HUMANS” of chapter 8.

Line in NCERT: "Plasmodium enters the human body as sporozoites (infectious form) through the bite of infected female Anopheles mosquito."

• Transplantation of tissue/organ often fails due to non-acceptance by the patient’s body therefore, tissue matching and blood group matching are essential before undertaking any graft/transplant.
• When the immune system recognises the protein in the transplanted tissue or organ as foreign, it initiates cellular immunity. As a result of this, there is a rejection of transplanted organs.
• Graft rejection is due to a cell-mediated immune response. Cell-mediated immunity enables the body to differentiate between self and non-self.
• To suppress the immune response during transplantation, histocompatibility antigen and immunosuppressants play an important role.

Hence, the correct option is A.

Topic in NCERT: Cell-mediated immune response or cell-mediated immunity (CMI)

Line in NCERT: "The body is able to differentiate 'self' and 'nonself and the cell-mediated immune response is responsible for the graft rejection."

• Typhoid is caused by Salmonella typhi. It is a Gram-negative bacterium.
• Typhoid fever can be confirmed by the Widal test, which is based on an antigen-antibody reaction.
• Plasmodium vivax causes malaria and Streptococcus pneumoniae is the causative agent of pneumonia. 
• Anthrone test is used for carbohydrate quantification.

Hence, the correct option is B.

Topic in NCERT: PATHOGENIC ORGANISMS AND DISEASES

Line in NCERT: "Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings." "Typhoid fever could be confirmed by Widal test."

An illness that occurs when the body tissues are attacked by its own immune system is known as autoimmune disease.

• Psoriasis, Vitiligo and Rheumatoid arthritis are autoimmune diseases.
• Alzheimer's is caused by brain cell death. It is a neurodegenerative disease. There is progressive brain cell death that happens over time. It is not an autoimmune disease.

Hence, the correct option is A.
NCERT Reference: Page no. 153 of topic “8.2.6 Auto Immunity” of chapter 8 of NCERT.

• Antivenom injection is an antiserum (preformed antibodies) which is obtained from the snake poison and it is transferred to the person with a snake bite. It is used to provide immediate immunity in case of emergency.
• Polio vaccines are vaccines used to prevent poliomyelitis (polio). Two types are used - an inactivated poliovirus (antigen) given by injection and an attenuated poliovirus (antigen) given by mouth. Oral polio vaccine contains the live attenuated pathogen which can induce an immune response in the recipient without making them ill.
• The inactivated polio vaccines are very safe. Mild redness or pain may occur at the site of injection. Oral polio vaccines cause vaccine-associated paralytic poliomyelitis.

Hence, the correct option is D.

NCERT Reference: Page no. 152 of topic “8.2.4 Vaccination and Immunisation” of chapter 8 of NCERT.

• Autoimmunity is a disorder of the body’s defence mechanism in which an immune response is elicited against its own tissues, which are thereby damaged or destroyed.
• Autoimmunity may be caused due to genetic or environmental factors.

Hence, the correct option is C.
NCERT Reference: Page no. 153 of topic “8.2.6 Auto Immunity” of chapter 8 of NCERT.

Line in NCERT: "due to genetic and other unknown reasons, the body attacks self-cells. This results in damage to the body and is called auto-immune disease."

• Encephalitis is a disease of inflammation of the brain. It is not transmitted sexually. Most commonly it is caused by a virus.
• Syphilis is a bacterial infection usually spread by sexual contact. The disease starts as a painless sore — typically on your genitals, rectum or mouth. Syphilis spreads from person to person via skin or mucous membrane contact with these sores.
• Trichomoniasis (or “trich”) is a very common sexually transmitted disease (STD). It is caused by infection with a protozoan parasite called Trichomonas vaginalis.
• AIDS (Acquired Immune Deficiency Syndrome) is the final and most serious stage of HIV disease, which causes severe damage to the immune system.

HIV has been found in saliva, tears, nervous system tissue, blood, semen (including pre-seminal fluid, or "pre-cum"), vaginal fluid, and breast milk. However, only blood, semen, vaginal secretions, and breast milk have been proven to transmit the infection to others.

Hence, the correct option is C.

NCERT Reference: Topic “8.1 COMMON DISEASES IN HUMANS” of chapter 8 of NCERT.

• After infection, HIV starts to destroy the T cells (T-helper lymphocytes). T cells are very important for the immune system.
• In the early stage of infection, a decline in numbers of T cells is observed.
• When the virus enters the host cell, reverse transcriptase, which is virally encoded, converts the RNA into DNA.
• The DNA of the virus is integrated into the DNA of cells with the help of integrase, and thus replication begins. This is identified by a reduction in the amount of helper T cells compared to normal helper T cells.

Hence, the correct option is B.

Topic in NCERT: HUMAN HEALTH AND DISEASE

Line in NCERT: "Simultaneously, HIV enters into helper T-lymphocytes (T), replicates and produce progeny viruses."

• Entamoeba histolytica is a pathogenic amoeba that is well-known for infecting humans with intestinal and extraintestinal infections.
• The trophozoites of Entamoeba secrete proteolytic enzymes which partially dissolve and loosens the mucosa, submucosa, and blood capillaries of the colon wall.
• On entering the colon, it actively ingests intestinal tissues and RBCs. 
• Serious damage ulceration is observed in the colon wall. This E. histolytica feeds on erythrocyte, mucosa, and submucosa of the colon which leads to amoebiasis.

Hence, the correct option is D.

NCERT Reference: Page no. 146 of topic “​8.1 COMMON DISEASES IN HUMANS” of chapter 8 of NCERT.

• HIV: is transmitted through blood, semen, breast milk, and other body fluids.
• Chikungunya: is an infection caused by the chikungunya virus. It is a viral disease transmitted to humans by infected mosquitoes.
• Ebola virus: has been detected in blood and many body fluids. Body fluids include saliva, mucus, vomit, faeces, sweat, tears, breast milk, urine, semen, and vaginal fluids.
• Hepatitis B: is usually spread through blood, semen, or other body fluids from a person infected with the virus.

Hence , the correct answer is option B
NCERT Reference: Page no. 150 of topic “​8.1 COMMON DISEASES IN HUMANS” of chapter 8 of NCERT.

(a) - (iv) Tuberculosis vaccine (BCG) has inactivated bacteria.
(b) - (iii) In the whooping cough vaccine, there are killed pathogens of Bordetella pertussis which cause whooping cough.
(c) - (ii) In DPT, diphtheria toxoid is present.
(d) - (i) Sabin polio vaccine contains inactivated virus.

Hence, the correct answer is option B.

NCERT Reference: Page no. 152 of topic “8.2.4 Vaccination and Immunisation” of chapter 8 of NCERT.

• IgA is found in the body’s external secretion, such as milk and colostrum.
• Colostrum contains high levels of lgA, which gives passive immunity to the child.

Hence, the correct option is B.

Topic in NCERT: Active and Passive Immunity

Line in NCERT: "The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant."

Serum globulins test provides confirmatory evidence measuring the deficiency of antibodies (γ -globulin) in a person.

Hence, the correct option is C.

Line in NCERT: "These proteins are called antibodies."

• Babesiosis is malaria like disease caused by protozoan-Babesia. 
• Babesiosis is transmitted to humans by ticks, and it frequently coexists with other tick-borne disorders like Lyme disease.
• Symptoms include fever, chills, bodily aches, and loss of appetite etc. 
• In this disease hemoglobinuric fever takes place.

Hence, the correct option is B.

Line in NCERT: "Some of the human diseases are caused by protozoans too. You might have heard about malaria, a disease man has been fighting since many years. Plasmodium, a tiny protozoan is responsible for this disease."

• The given image shows the flowers of the Datura plant. Datura is a psychedelic plant. It contains tropane alkaloids which can cause hallucinations.
• The drug obtained from Datura is hallucinogenic which produces a dream-like state and can even cause psychosis, a condition of loss of contact with external reality.

Hence, the correct option is A.
NCERT Reference: Page no. 159 of topic “8.5 DRUGS AND ALCOHOL ABUSE” of chapter 8 of NCERT

Line in NCERT: "Several plants, fruits and seeds having hallucinogenic properties have been used for hundreds of years in folk-medicine, religious ceremonies and rituals all over the globe."

• In many patients, symptoms of HIV infection do not occur until stage 3 of the infection. HIV selectively destroys helper T-lymphocytes. It, therefore, causes symptoms of immunodeficiency due to a critically low number of helper T-lymphocytes.
• Stage 3 is usually a period where the severity and frequency of these infections and neoplasms are directly related to the decline of CD4+ T cells or helper T-lymphocytes.

Hence, the correct option is C.

Topic in NCERT: AIDS

Line in NCERT: "When HIV damages a large number of helper T-lymphocytes."

• Mucosa Associated Lymphoid Tissue constitutes about 50% of the lymphoid tissue in the human body. It is scattered along the mucosal lining in the human body.
• There are three types of situations in which MALT is present: Tonsils, Appendix, & small intestine area.

Hence , the correct option is A.

Topic in NCERT: Lymphoid organs

Line in NCERT: "It constitutes about 50 per cent of the lymphoid tissue in human body."

• Asthma may be attributed to allergic reaction of the mast cells in the lungs.
• Asthma symptoms, which include coughing, wheezing, and chest tightness, are common in an asthma attack. Sometimes asthma is called bronchial asthma or reactive airway disease. 
• Mast cells secrete the autacoid mediators histamine, prostaglandin (PG) D2, and leukotriene (LT) C4, which are capable of inducing bronchoconstriction, mucus secretion, and mucosal edema, all features of asthma.

Hence, the correct option is B.

NCERT Reference: Page no. 153 of topic “8.2.5 Allergies” of chapter 8 of NCERT.