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

• Neoplastic characteristics of cells refer to the properties of cells that are involved in the formation of neoplasms or tumors.
• Neoplastic or tumor cells grow very rapidly, invading and damaging the surrounding normal tissues. As these cells actively divide and grow they also starve the normal cells by competing for vital nutrients.
• Cells sloughed from such tumors reach distant sites through blood, and wherever they get lodged in the body, they start a new tumor there.
  • A. A mass of proliferating cells: Neoplastic cells form abnormal masses due to their unregulated growth and proliferation.
  • B. Rapid growth of cells: Neoplastic cells exhibit rapid and uncontrolled growth, which is one of the hallmarks of cancer.
  • C. Invasion and damage to the surrounding tissue: Neoplastic cells often have the ability to invade and damage surrounding tissues, leading to metastasis.
  • D. Those confined to original location: This characteristic refers to benign tumors, which are not usually invasive and remain localized. However, this is not a defining characteristic of all neoplastic cells, particularly malignant ones.

• Computed tomography (CT) and magnetic resonance imaging (MRI) detect cancers of internal organs (A): CT and MRI are advanced imaging technologies used to visualize internal structures of the body. They are highly effective in detecting tumors and abnormalities within internal organs.
• α-interferon activates the cancer patients’ immune system and helps in destroying the tumor (C): α-interferon is a type of cytokine that boosts the immune system, enabling it to better target and destroy cancer cells.

Incorrect statements:

• Chemotherapeutic drugs are used to kill non-cancerous cells): Incorrect because chemotherapeutic drugs are designed to target and kill rapidly dividing cancer cells, although they can sometimes affect non-cancerous cells as well.
• Chemotherapeutic drugs are biological response modifiers: Incorrect because biological response modifiers are different types of therapies like α-interferon, used to enhance the body's immune response, not chemotherapeutic drugs.
• In the case of leukemia, blood cell counts are decreased: Incorrect because in leukemia, there is generally an abnormal increase in white blood cell counts, not a decrease.

• Spleen (C): The spleen filters blood and is a site where lymphocytes interact with blood-borne antigens. It plays a crucial role in immune responses to pathogens circulating in the bloodstream.
• Lymph Nodes (D): Lymph nodes are distributed throughout the body and filter lymph. They trap antigens from lymphatic fluid and allow interaction between lymphocytes and antigens, activating adaptive immune responses.
• Peyer’s Patches (E): Peyer’s patches are specialized mucosa-associated lymphoid tissues in the small intestine. They monitor intestinal contents for antigens and are essential for immune responses in the gut-associated lymphoid tissue (GALT).

Incorrect Options:

• Thymus (A): The thymus is a primary lymphoid organ responsible for the maturation of T cells. 
• Bone Marrow (B): The bone marrow is another primary lymphoid organ responsible for the development and maturation of B cells.

• Immunity refers to the ability of the body to resist harmful microorganisms or toxins and protect against diseases.
• There are two main types of immunity in the human body: innate immunity and acquired immunity.
  • Innate immunity is present from birth and provides non-specific defense mechanisms against pathogens.
  • Acquired immunity develops during an individual's lifetime and is specific to particular pathogens.
• Innate immunity is the body's first line of defense against infections and is present at the time of birth.
• It does not target specific pathogens; instead, it provides a general defense against all harmful microorganisms.
• Components:
  • Physical barriers such as skin and mucous membranes prevent the entry of pathogens.
  • Physiological barriers include acid in the stomach, saliva in the mouth, tears from eyes–all prevent microbial growth.
  • Cellular components such as certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes.
  • Cytokine barriers: Virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infection. 

Other Options:

• Acquired Immunity:
  • This type of immunity develops after exposure to specific pathogens.
  • It involves the production of antibodies and memory cells, making it pathogen-specific.
  • It is characterised by memory.
• Cell-Mediated Immunity:
  • This is a type of acquired immunity where T-cells (a type of white blood cell) play a central role in defending against intracellular pathogens, such as viruses and some bacteria.
• Humoral Immunity:
  • This is another type of acquired immunity where B-cells produce antibodies to target specific pathogens. Like cell-mediated immunity, it is specific and develops after exposure to pathogens

• Option 1: "Each antibody has two light and two heavy chains" is correct. Each antibody molecule comprises two identical heavy chains and two identical light chains.
• Option 2: "The heavy and light chains are held together by disulfide bonds" is correct. Disulfide bonds between the chains provide structural integrity to the antibody molecule.
• Option 3: "Antigen binding site is located at C-terminal region of antibody molecules" is incorrect. The antigen binding site is located at the N-terminal region where the variable regions are present.
• Option 4: "Constant region of heavy and light chains are located at C-terminus of antibody molecules" is correct. The constant regions are situated at the C-terminal ends and are involved in effector functions of antibodies.

To correctly match the items in List I with List II, we need to understand each term and its relationship:
Common Cold is primarily caused by Rhinoviruses. Hence, A is linked with III.
Haemozoin is a byproduct of the digestion of blood by parasites such as Plasmodium (which causes malaria). Therefore, B corresponds with I.
Widal test is a diagnostic test for Typhoid fever, caused by the bacterium Salmonella Typhi. Thus, C matches with II.
Allergy can be triggered by many allergens, including Dust Mites, which are a common cause of respiratory and dermatological allergies. Consequently, D aligns with IV.
Based on this, the matching should be:
A-III, B-I, C-II, D-IV
Therefore, the correct answer is: Option C: A-III, B-I, C-II, D-IV

To solve this matching problem, we need to identify which plant or application each substance in List I is correctly associated with in List II.

List I (Substances) and List II (their sources or uses):
Cocaine - Cocaine is derived from the coca plant, known scientifically as Erythroxylum. This matches with III in List II.
Heroin - Heroin is derived from the opium poppy, Papaver somniferum. This corresponds to IV in List II.
Morphine - Like heroin, Morphine is also derived from the opium poppy, Papaver somniferum. However, morphine is also directly associated with its use as a sedative in surgery, making I a valid association for its usage.
Marijuana - Marijuana is derived from Cannabis sativa, which corresponds to II in List II.

With this information:

A (Cocaine) matches with III (from Erythroxylum).
B (Heroin) matches with IV (Papaver somniferum).
C (Morphine) as an effective sedative in surgery matches with I.
D (Marijuana) matches with II (Cannabis sativa).

The correct matching based on the provided options is: Option D: A-III, B-IV, C-I, D-II
This option correctly matches the substance with their respective sources or primary uses.

Bone marrow is the main lymphoid organ responsible for producing all blood cells, including lymphocytes. The thymus, located near the heart and beneath the breastbone, is essential for the development of T-lymphocytes. Here are some key points regarding these organs:

• The bone marrow produces all types of blood cells.
• The thymus is larger at birth but shrinks with age.
• Both organs create micro-environments for T-lymphocyte maturation.

Additionally, the spleen and lymph nodes play significant roles:

• The spleen filters blood and stores lymphocytes and phagocytes.
• Lymph nodes trap microorganisms and activate lymphocytes for immune responses.

In summary, both statements about the bone marrow and thymus are correct, as they are crucial for the production and maturation of lymphocytes.

To correctly match List I (Diseases) with List II (Pathogen Types), we need to understand the causative agents for each disease listed in List I.

Details for each disease:

Typhoid: This is a bacterial infection caused by Salmonella typhi. Hence, it matches with "Bacteria".
Leishmaniasis: This disease is caused by parasitic protozoans of the genus Leishmania. Therefore, it corresponds to "Protozoa".
Ringworm: Despite its name, ringworm is not caused by a worm. It’s a fungal infection on the skin, caused by various types of fungi. So, Ringworm should be associated with "Fungus".
Filariasis: Also known as lymphatic filariasis, this condition is caused by infection with parasites classified as nematodes (roundworms) of the family Filarioidea. Thus, it matches with "Nematode".

With this understanding:
A should be paired with IV (Bacteria).
B should be paired with III (Protozoa).
C should be paired with I (Fungus).
D should be paired with II (Nematode).

Corresponding to the options provided:

Option A: A-I, B-III, C-II, D-IV - Incorrect
Option B: A-IV, B-III, C-I, D-II - Correct!
Option C: A-III, B-I, C-IV, D-II - Incorrect
Option D: A-II, B-IV, C-III, D-I - Incorrect

Therefore, the correct answer is Option B: A-IV, B-III, C-I, D-II.

Option (a) is the correct answer because: 

• Ringworm is a fungal infection of the skin, hair, or nails.It is caused by various species of dermatophyte fungi, including Trichophyton, Microsporum and  Epidermophyton.
• Filariasis is a parasitic disease caused by several species of thread-like nematode worms (filarial worms). The most common filarial worms causing the disease include Wuchereria bancrofti. It is a  causative agent of lymphatic filariasis, a type of filariasis that affects the lymphatic system.
• Malaria is a mosquito-borne infectious disease caused by Plasmodium parasites.
• Pneumonia is an infection that inflames the air sacs in one or both lungs, and it can be caused by various infectious agents, including bacteria, viruses, fungi, and other microorganisms. Haemophilus influenzae is indeed one of the bacteria that can cause pneumonia, especially in certain populations, like children and older adults.

• Heroin belongs to the category of opioids and it is a depressant that slows down body functions.
• Marijuana is known for its effect on the cardiovascular system of the body.
• Cocaine interferes with the transport of the neurotransmitter dopamine.
• Morphine is used is a sedative and painkiller.

HIV, or the Human Immunodeficiency Virus, primarily infects CD4+ T cells, which are a type of T cell. In the context of the options given, TH cells, or T helper cells, are a subset of CD4+ T cells.

There are two main types of immunity in human body:
1. Innate immunity is the non-specific immunity present at the time of birth. This works on physical, physiological, cytological and chemical barriers.
2. Acquired immunity is the adaptive or specific immunity which a person develops during his/her lifetime. This works by B-cell and T-cells of the body.

• Option (c) is the correct answer as autoimmune disorder is a condition where body defense mechanism recognises its own cells as foreign bodies. Sometimes, due to genetic and other unknown reasons, the body attacks self cells.
• Rheumatoid arthritis is an example where. This statement is incorrect. Rheumatoid arthritis (RA) is an autoimmune disorder where the immune system attacks the joints (attacks self cells ,synovial membrane), which are part of the body's own tissues. So, the body is indeed attacking its own cells in the case of RA.

So Statement I is correct but Statement II is incorrect.

• Option (1) is the correct answer as the body is able to differentiate between ‘self’ and ‘non-self’ and the cell-mediated immune response is responsible for the graft rejection.
• Option (2) is incorrect as body of higher vertebrates have the ability to differentiate foreign organisms from self cells.
• Option (4) is incorrect as the autoimmune response occur when the body’s immune system fails to recognize ‘self’ from ‘non-self’ and starts destroying the body’s own cells.

• Option (a) is the correct answer because cellular barriers include NK cells, macrophages (monocytes) and neutrophils (PMNL).
• Cytokine barriers include interferons.
• Physical barriers include mucus membranes and skin.
• Physiological barriers include HCl in gastric juice, saliva and tears etc.

• 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.