Immunity — Set 1
Biology · रोग प्रतिरोधक क्षमता · Questions 1–10 of 50
Which type of white blood cells are primarily responsible for producing antibodies?
Correct Answer: A. B-lymphocytes
B-lymphocytes differentiate into plasma cells to secrete specific antibodies. These antibodies neutralize pathogens like bacteria and viruses circulating in the blood. They are a core component of the adaptive immune system.
What is the primary function of the 'Memory cells' in the immune system?
Correct Answer: A. To remember previous infections
The correct answer is 'To remember previous infections'. Memory cells persist in the body after an initial infection is cleared. They recognize the same pathogen quickly if it enters the body again. This ensures a faster and stronger secondary immune response.
Which of the following is considered the 'First line of defense' in human immunity?
Correct Answer: A. Skin and Mucous membranes
The skin provides a physical barrier that prevents most microbes from entering. Mucous membranes trap pathogens in the respiratory and digestive tracts. This non-specific barrier acts before any internal immune response begins.
Which organ is often called the 'Graveyard' of red blood cells and acts as a major filter for the blood?
Correct Answer: D. Spleen
The spleen filters out old red blood cells and recycles their components. It also contains high concentrations of white blood cells to detect blood-borne pathogens. This organ plays a vital role in both circulatory and immune functions.
What type of immunity is gained when a person recovers from a disease like chickenpox?
Correct Answer: D. Natural Active Immunity
Natural active immunity occurs when the body's own immune system produces antibodies in response to an actual infection. This usually provides long-term protection against the same disease. It is distinguished from immunity gained through vaccination.
Which chemical is released by mast cells during an allergic reaction?
Correct Answer: A. Histamine
Histamine increases the permeability of blood vessels to white blood cells and proteins. This leads to common allergy symptoms like swelling, itching, and redness. Antihistamine drugs are used to neutralize these specific effects.
The transfer of antibodies from a mother to her infant through breast milk is an example of?
Correct Answer: D. Natural Passive Immunity
Natural passive immunity involves the direct transfer of pre-formed antibodies from one person to another. It provides immediate but temporary protection to the infant while their own system matures. Colostrum is particularly rich in these protective antibodies.
Which gland is responsible for the maturation of T-lymphocytes?
Correct Answer: A. Thymus
The thymus is a primary lymphoid organ located in the upper chest. T-cells migrate from the bone marrow to the thymus to undergo critical development. This gland is most active during childhood and shrinks after puberty.
What is the medical term for the body's immune system attacking its own healthy cells?
Correct Answer: C. Autoimmunity
Autoimmunity occurs when the immune system fails to distinguish between self and non-self molecules. This results in the destruction of the body's own tissues and organs. Rheumatoid arthritis and Type 1 diabetes are common examples of this condition.
Which proteins are produced by virus-infected cells to protect neighboring healthy cells?
Correct Answer: D. Interferons
Interferons signal nearby cells to heighten their anti-viral defenses. They inhibit viral replication within the neighboring healthy tissue. These proteins are a crucial part of the innate immune system's early response.