Biology

Human Immunity and Blood

2,051 Questions

Human immunity and blood questions cover the physiological mechanisms protecting the body against diseases and the components of blood. Topics include blood groups, cell mediated immunity, monoclonal antibodies, and blood coagulation. These biology topics frequently appear in general science sections of competitive exams.

Blood groupsCell mediated immunityMonoclonal antibodiesBlood coagulationCancer immunology

Human Immunity and Blood Questions

Multiple choice

What is the process by which phagocytes engulf and internalize foreign particles called?

  1. Chemotaxis

  2. Opsonization

  3. Phagocytosis

  4. Cytokinesis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Phagocytosis is the process by which phagocytes extend their pseudopodia and engulf foreign particles, forming a phagosome.

Multiple choice

What is the role of opsonins in phagocytosis?

  1. Activating complement proteins

  2. Binding to pathogens and enhancing phagocytosis

  3. Producing antibodies

  4. Releasing histamine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Opsonins are proteins that coat pathogens, making them more recognizable and easier for phagocytes to engulf.

Multiple choice

Which of the following is NOT a type of phagocyte?

  1. Neutrophils

  2. Macrophages

  3. Dendritic cells

  4. Erythrocytes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Erythrocytes, also known as red blood cells, are not phagocytes. Phagocytes are specialized white blood cells that engulf and destroy pathogens.

Multiple choice

What happens to the engulfed material after phagocytosis?

  1. It is digested and broken down

  2. It is released back into the bloodstream

  3. It is stored in the phagocyte

  4. It is expelled from the body
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

After phagocytosis, the engulfed material is enclosed in a phagosome, which fuses with a lysosome to form a phagolysosome. Inside the phagolysosome, the material is digested and broken down by enzymes.

Multiple choice

Which of the following is a type of intracellular killing mechanism used by phagocytes?

  1. Antibody-mediated cytotoxicity

  2. Complement-mediated cytotoxicity

  3. Phagocytosis

  4. Oxidative burst
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Oxidative burst is an intracellular killing mechanism used by phagocytes to destroy engulfed pathogens. It involves the production of reactive oxygen species (ROS) and other antimicrobial substances that kill the pathogens.

Multiple choice

What is the role of macrophages in phagocytosis?

  1. They are the primary phagocytes in the blood

  2. They are tissue-resident phagocytes

  3. They produce antibodies

  4. They release histamine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Macrophages are tissue-resident phagocytes that are found in various tissues and organs throughout the body. They play a crucial role in phagocytosing pathogens, cellular debris, and foreign particles.

Multiple choice

Which of the following is NOT a function of phagocytes?

  1. Engulfing and destroying pathogens

  2. Producing antibodies

  3. Presenting antigens to immune cells

  4. Releasing cytokines
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Phagocytes do not produce antibodies. Antibody production is a function of B cells and plasma cells.

Multiple choice

What is the role of dendritic cells in phagocytosis?

  1. They are the primary phagocytes in the blood

  2. They are tissue-resident phagocytes

  3. They present antigens to immune cells

  4. They release histamine
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Dendritic cells are specialized phagocytes that are particularly adept at capturing and presenting antigens to immune cells, such as T cells. This process is crucial for initiating an adaptive immune response.

Multiple choice

Which of the following is a type of phagocytic cell found in the liver?

  1. Neutrophils

  2. Macrophages

  3. Kupffer cells

  4. Eosinophils
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Kupffer cells are specialized macrophages found in the liver. They play a crucial role in phagocytosing pathogens, cellular debris, and foreign particles in the liver.

Multiple choice

What is the role of cytokines in phagocytosis?

  1. They activate complement proteins

  2. They bind to pathogens and enhance phagocytosis

  3. They produce antibodies

  4. They regulate the activity of phagocytes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cytokines are small proteins that regulate the activity of phagocytes. They can stimulate phagocytosis, enhance the killing ability of phagocytes, and promote the recruitment of other immune cells to the site of infection.

Multiple choice

Which of the following is a type of phagocytic cell found in the brain?

  1. Neutrophils

  2. Macrophages

  3. Microglia

  4. Eosinophils
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Microglia are specialized macrophages found in the brain and spinal cord. They play a crucial role in phagocytosing pathogens, cellular debris, and foreign particles in the central nervous system.

Multiple choice

What is the role of neutrophils in phagocytosis?

  1. They are the primary phagocytes in the blood

  2. They are tissue-resident phagocytes

  3. They produce antibodies

  4. They release histamine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Neutrophils are the most abundant type of phagocytes in the blood and are the primary cells responsible for phagocytosis during the early stages of an immune response.

Multiple choice

Which of the following is a type of phagocytic cell found in the lungs?

  1. Neutrophils

  2. Macrophages

  3. Alveolar macrophages

  4. Eosinophils
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Alveolar macrophages are specialized macrophages found in the lungs. They play a crucial role in phagocytosing pathogens, cellular debris, and foreign particles in the lungs.

Multiple choice

Which type of immune cell is responsible for phagocytosing and destroying foreign particles?

  1. Neutrophils

  2. Macrophages

  3. Dendritic cells

  4. Lymphocytes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Macrophages are phagocytic cells that engulf and destroy foreign particles, including bacteria, viruses, and cellular debris.

Multiple choice

Which type of immunological disorder is characterized by the production of autoantibodies that attack the body's own tissues?

  1. Immunodeficiency disorder

  2. Allergic disorder

  3. Autoimmune disorder

  4. Hypersensitivity disorder
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Autoimmune disorders are characterized by the production of autoantibodies that mistakenly attack and damage the body's own tissues, leading to various symptoms and conditions.