Immunity — Set 3
Biology · रोग प्रतिरोधक क्षमता · Questions 21–30 of 50
Which type of immunity is present from birth and is non-specific?
Correct Answer: D. Innate Immunity
Innate immunity includes physical barriers, chemical barriers, and certain white blood cells. It provides an immediate, general response to any foreign invader. It does not change or improve with repeated exposure to the same pathogen.
What is the primary site of white blood cell production in an adult?
Correct Answer: C. Bone Marrow
Red bone marrow is the soft tissue inside large bones where hematopoiesis occurs. It produces all types of blood cells, including leukocytes and erythrocytes. This production is constantly regulated based on the body's needs.
An exaggerated immune response to a harmless environmental substance is called?
Correct Answer: B. Allergy
The correct answer is 'Allergy'. Allergies occur when the immune system overreacts to substances like pollen, dust, or certain foods. These substances are called allergens and trigger the release of inflammatory chemicals. In severe cases, this can lead to life-threatening anaphylactic shock.
Which cell acts as a 'bridge' by activating both B-cells and Cytotoxic T-cells?
Correct Answer: C. Helper T-cells
Helper T-cells secrete cytokines that coordinate the overall immune response. Without these cells, the adaptive immune system cannot function effectively. They are the specific targets of the virus that causes AIDS.
Which fluid is collected and filtered by the lymph nodes?
Correct Answer: D. Lymph
Lymph is a clear fluid that leaks out of blood capillaries into tissue spaces. Lymph nodes filter this fluid to trap pathogens and activate immune cells. The filtered lymph is eventually returned to the general blood circulation.
Which of the following is a physical barrier of the immune system?
Correct Answer: B. Skin
The skin is the body's largest organ and serves as the primary physical barrier. It prevents the entry of bacteria and other harmful organisms into the internal environment. Intact skin is highly effective at stopping most common infections.
The ability of the immune system to recognize a specific pathogen is called?
Correct Answer: C. Specificity
Specificity allows the immune system to distinguish between very similar pathogens. It targets only the specific invader that triggered the response. This is a hallmark feature of the adaptive immune system.
Which white blood cells are the first to arrive at the site of an infection?
Correct Answer: C. Neutrophils
Neutrophils are the most abundant type of white blood cell in the blood. They move rapidly to infected areas and kill pathogens through phagocytosis. Their short lifespan often leads to the formation of pus at the infection site.
Which of the following is used to treat a person immediately after a venomous snake bite?
Correct Answer: A. Antivenom
Antivenom contains pre-formed antibodies that neutralize snake toxins immediately. This provides artificial passive immunity to save the person's life. It does not provide any long-term protection against future bites.
Humoral immunity is primarily mediated by which of the following?
Correct Answer: B. Antibodies
Humoral immunity refers to immune responses that involve the production of antibodies. These antibodies circulate in the 'humors' or body fluids like blood and lymph. This system is primarily directed against extracellular pathogens.