Immunity — Set 5
Biology · रोग प्रतिरोधक क्षमता · Questions 41–50 of 50
Which of the following is a vaccine-preventable disease?
Correct Answer: B. Polio
Polio is a highly infectious viral disease that can cause irreversible paralysis. Widespread vaccination campaigns have almost completely eliminated polio from most parts of the world. Vaccines stimulate active immunity to protect individuals from infection.
What is the role of 'Complement proteins' in the immune system?
Correct Answer: B. They help antibodies destroy bacteria
The complement system consists of a group of proteins that 'complement' the work of antibodies. They can punch holes in bacterial cell walls or mark pathogens for phagocytosis. This system is part of the innate immune response but supports adaptive immunity.
Where are all blood cells, including those of the immune system, originally produced?
Correct Answer: A. Bone Marrow
Bone marrow contains multipotent stem cells that give rise to all blood cell lineages. This includes red blood cells, platelets, and all types of white blood cells. This process occurs in the central cavities of many bones.
Which immunoglobulin is the first to be produced during a primary immune response?
Correct Answer: B. IgM
IgM is a large antibody that appears soon after the body first encounters a new antigen. Because of its size, it is very effective at clumping pathogens together. It is later replaced by more specialized antibodies like IgG.
Which cells in the stomach produce acid that kills many swallowed pathogens?
Correct Answer: B. Parietal cells
Parietal cells in the stomach lining secrete hydrochloric acid. This highly acidic environment is a chemical barrier that destroys most bacteria in food. This acts as a protective measure for the digestive system.
What is the primary function of 'Natural Killer' (NK) cells?
Correct Answer: A. Killing virus-infected and tumor cells
NK cells are a type of lymphocyte that provides rapid responses to viral-infected cells. Unlike T-cells, they do not require specific antigen recognition to act. They are a critical part of the innate immune system's defense against cancer.
Acquired immunity is characterized by which of the following?
Correct Answer: C. It has memory
Acquired or adaptive immunity develops after exposure to a specific pathogen. It is highly specific and creates memory cells for future protection. This memory allows for a much more rapid response upon re-infection.
Which lymphoid organ is located in the upper left part of the abdomen?
Correct Answer: D. Spleen
The spleen is the largest lymphoid organ in the human body. It filters blood, removes old cells, and holds a reservoir of monocytes. Its location makes it vulnerable to injury from blunt force trauma to the abdomen.
Which of the following is a characteristic symptom of the 'Inflammatory response'?
Correct Answer: B. Swelling and Redness
Redness and swelling are caused by increased blood flow and fluid leakage into the tissues. This helps to bring immune cells and nutrients to the site of injury. It is a vital part of the body's non-specific defense mechanism.
What is the primary function of the 'Helper T-cells'?
Correct Answer: C. Activating other immune cells
Helper T-cells act as the coordinators of the entire immune response. They release chemical signals that tell B-cells to produce antibodies and T-cells to attack. Their loss leads to a complete failure of the adaptive immune system.