Biology

Human Immunity and Blood

2,096 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 biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

Low platelet count results in

  1. Low bleeding

  2. Excessive bleeding

  3. Growth

  4. Both B and C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Platelets are the parts of the blood that help the blood clot. They are smaller than red or white blood cells. If the number of platelets is too low, excessive bleeding can occur. However, if the number of platelets is too high, blood clots can form thrombosis, which may obstruct blood vessels and result in such events as a stroke. 

Therefore, the correct answer is option B.

Multiple choice biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

Megakaryocytes, special cells in the bone marrow that produce cell fragments are called :

  1. Leucocytes

  2. Erythrocytes

  3. Thrombocytes

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

Megakaryocyte is a large bone marrow cell which are responsible for the production of thrombocytes. Thrombocytes help in normal blood clotting.

Hence, he correct option is C.

Multiple choice biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

Select the incorrectly matched pair.

  1. Leukopenia - Fall in WBCs count

  2. Polycythemia - Abnormal rise in RBCs count

  3. Thrombocytosis - Decrease in number of platelets

  4. Erythrocytopenia - Decrease in number of RBCs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(a) Leukopenia is the decrease in the white blood cell count in the cells. 

(b) Polycythemia is a state in which the percentage of red blood cells in our body is elevated. 
(c) Thrombocytosis is the condition in which there is an excessive number of platelets in the blood cell.
(d) Erythrocytopenia-  It is a state in which there is a deficiency of Red blood cells in our body.
So, the correct option is 'Thrombocytosis- Decrease in a number of platelets'.

Multiple choice zoology immunity and blood groups immunity and the lines of immunity immune system of the body aids to health

Mast cells secrete.

  1. Serotonin

  2. Heparin

  3. Histamine

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Mast cells are found in mucous membranes and connective tissues and are important for wound healing and defense against pathogens via the inflammatory response.
  • The mast cell granules are composed of serotonin, heparin, and histamine. They secrete serotonin, heparin, and histamine when they are activated in the presence of the toxic substance or a pathogen.
  • Hence Mast cells secrete 'serotonin, heparin, and histamine'.
  • So, the correct answer is 'All the above'.
Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Which of the following are involved in body defence?

  1. Neutrophils

  2. Lymphocytes

  3. Macrophages

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The cells of the immune system can be categorized as lymphocytes (T-cells, B-cells and NK cells), neutrophils, and monocytes/macrophages. These are all types of white blood cells.
  • Neutrophils are phagocytic cells that are also classified as granulocytes because they contain granules in their cytoplasm. These granules are very toxic to bacteria and fungi and cause them to stop proliferating or die on contact.
  • B lymphocytes provide humoral immunity and T lymphocytes provide cellular immunity.
  • Macrophages are efficient phagocytic cells that can leave the circulatory system by moving across the walls of capillary vessels. The ability to roam outside of the circulatory system is important because it allows macrophages to hunt pathogens with less limits. Macrophages can also release cytokines in order to signal and recruit other cells to an area with pathogens.
  • Hence Neutrophils, Lymphocytes, and Macrophages are involved in body defense.
  • So, the correct answer is 'All the above'.
Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Antigen-presenting cells communicate with effector cells of the immune system. Select the correct statement.

  1. Direct cell membrane- to- membrane contact

  2. Quorum sensing

  3. Release of highly specific steroidal hormones

  4. Release of neurotransmitter-like substances

  5. Induction of rapid ion flow through the membrane
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is option A i.e. "Direct cell membrane- to- membrane contact"
Antigen-presenting cells (APC) are immune system cells that present antigens on the cell surface which then communicate with appropriate T cell receptors by membrane-to-membrane contact. Antigen-presenting cells are involved in both the innate and adaptive immune responses.

Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Identify the incorrect statement about antibodies.

  1. Antibodies are produced by different combinations of soluble proteins in the blood called complement.

  2. When antibodies bind to a bacterial cell, it may keep that cell from adhering to host cells.

  3. The specific receptors on T cells that would interact with a specific antigen are the same shape as antibodies that will interact with that antigen.

  4. By binding to antigens, antibodies mark those antigens for destruction by macrophages.

  5. By binding to an invader, antibodies attract proteins that lyse the target membrane.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Antibodies are produced by different combinations of soluble proteins in the blood called complement. These are produced by specialized white blood cells called B lymphocytes (or B cells). When an antigen binds to the B-cell surface, it stimulates the B cell to divide and mature into a group of identical cells called a clone.
Antibodies recognize specific antigens by identifying certain areas on the surface of the antigen known as antigenic determinants. Once the specific antigenic determinant is recognized, the antibody will bind to the determinant. The antigen is tagged as an intruder and labeled for destruction by other immune cells.
So, the correct answer is option A.

Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

The antibody production in the body is due to

  1. B cell

  2. Fibrinogen

  3. Pathogen

  4. Phagocyte

  5. T cell
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Antigens are proteins that are found on the surface of the pathogen and are unique to that pathogen. Pathogen induces the immune system when enters the body and produces antibodies against it. A type of white blood cell called a lymphocyte recognizes the pathogen as being foreign and produces antibodies that are specific to that pathogen or antigen. Each antibody has a unique binding site shape which locks onto the specific shape of the antigen. The antibodies destroy the antigen (pathogen) which is then engulfed and digested by macrophages.
So, the correct answer is option C.
Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Which of the following body defense mechanism traps, engulfs and sweeps disease-causing agents towards the body openings?

  1. Body secretions

  2. Enzymes and compounds in the blood

  3. Mucous membrane

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

. The mucous membrane is the epithelial tissue which lines several organs and secretes mucus. It stops pathogens and dirt from entering the body and to prevent bodily tissues by pushing disease causing agents towards body opening, it also prevents organs from  dehydration


So, the correct answer is 'Mucous membrane'

Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

A quick immune response that often eliminates the infection or keeps it in check until a specific acquired immune response can develop is called

  1. A nonspecific response, including macrophages and other nonspecific white blood cells.

  2. Acquired immunity, which develops after antibodies bind to specific antigens.

  3. The cell-mediated response in which T cells bind to antigen presenting cells (APCs).

  4. The humoral response where B cells that develop in the bone marrow produce plasma B cells.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Innate immune system is quick and non specific, it is the 1$^{st}$ immediate response of the body on infection. It is also referred to as primary response that would eliminate certain number of pathogens keeping the infection in check. 

So, the correct answer is 'A nonspecific response, including macrophages and other nonspecific white blood cells'


Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Which one of the following is devoid of macrophages?

  1. Lymph nodes

  2. Connective tissue

  3. Lungs

  4. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A. The lymph node is in the form of fibres called reticulum with white blood cells attached to it,  lymph sinus is lined by reticular cells and macrophages.

B. Macrophages are derived from monocytes (WBCs) and found in the connective tissue such as blood the bloodstream and they mature into macrophages as they leave the bloodstream.
C. Macrophage in the lungs are called alveolar macrophages or dust cell and clears the air spaces from infectious and toxic particles that have entered the body.
So the correct answer is 'None of the above'.

Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Active immunity is due to 

  1. Memory cells

  2. Killer T-cells

  3. Helper T-cells

  4. Suppressor T-cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Active immunity is the induction of immunity after exposure to an antigen. Antibodies are created by the recipient and may be stored permanently due to the activation of memory cells which recognizes the same antigen in future and destroy them. Active immunity can occur naturally when a microbe or other antigen is received by a person who has not yet come into contact with the microbe and has no pre-made antibodies for defence. The immune system will eventually create antibodies for the microbe, but this is a slow process.
So, the correct answer is 'Memory cells'.
Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Number of lymphocytes present in a healthy human is

  1. 1 trillion

  2. 100 billion

  3. 10 trillion

  4. 100 trillion
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A lymphocyte is one of the subtypes of white blood cell in a vertebrate's immune system. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic acquired immunity), and B cells (for humoral, antibody-driven adaptive immunity). The total number of lymphocytes present in healthy humans is approximately 1 trillion.

So, the correct answer is '1 trillion'.

Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Inflammatory response in allergy is due to release by mast cells of 

  1. Antibodies

  2. Antigens

  3. Histamine

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or allergy. The damaged cells release chemicals including histamine, bradykinin, and prostaglandins. Histamine is released from mast cells. These chemicals cause blood vessels to leak fluid into the tissues, causing swelling. 

So, the correct answer is 'Histamine'.

Multiple choice zoology aids to health immunity and the lines of immunity immune system of the body immunity and blood groups

Which of the following are involved in body defense?

  1. Neutrophils

  2. Macrophages

  3. Lymphocytes

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • In our body, neutrophils, macrophages and lymphocytes are involved in the second line of defence. They produce non-specific immune responses such as fever and inflammatory response.
  •  Neutrophils are a type of WBC and they form an essential part of the innate immune system. Neutrophils are one of the first-responders of inflammatory cells to migrate towards the site of inflammation.
  • Macrophages are the type of WBC which engulfs and digests cellular debris, foreign substances, microbes etc..
  • Lymphocytes are a type of WBC. It includes natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity). 
So, the correct answer is 'All of the above'.