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

Which of the following results from cell fragmentation?

  1. RBC

  2. WBC

  3. Plasma

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

Platelets are the cells found in blood which helps in the clotting of the blood. The formation of platelets takes place in bone marrow from large bone marrow cells known as megakaryocytes. These cells after becoming mature enough, undergo the process of cell fragmentation to produce platelet cells. The hormone that help in platelet production is thrombopoietin. 

So, the correct answer is D.

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 biology endocrine glands different type of gland glands in humans coordination in human beings- chemical control

Which is not involved in endocrine secretion? 

  1. Leydig cell

  2. Lutein cell

  3. Parafollicular cells of thyroid

  4. Kupffer cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Endocrine secretion is the secretion of hormones from endocrine glands which are ductless glands and secrete hormones into blood stream. 
  • Leydig cells are present in testis and secrete testosterone hormone.
  • Lutein cells are present in corpus luteum in ovary and secrete progesterone hormone.
  • Parafollicular cells of thyroid gland secrete calcitonin hormone.
  • Kupffer cells are phagocytic cells in liver that destroy or breakdown red blood cells.
Hence, Kupffer cells are not involved in endocrine secretion.
So, the correct answer is 'Kupffer cells'.
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

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

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
Read the passage and answer the following question.
Many mammalian cell membrane receptors associated with the immune system contain repetitive structures known as the immunoglobulin fold. Receptors containing even one of these folds are considered members of the immunoglobulin superfamily. 
Which of the following explains this common feature in different molecules?

  1. All of the genes that produce these proteins used to be part of a much larger gene that fragmented in the past

  2. All of the genes in question are retrotransposons

  3. Most of the genes in question are introns that experienced mutations that removed the splice sequence

  4. The fold was so successful as a signaling molecule that it encouraged its propagation

  5. The fold is repetitive because of gene duplication
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Repetitive gene products are produced by gene duplication. A duplicated gene produces the same protein in multiple repeats. Retrotransposons can amplify themselves but are not necessarily present in multiple copies at the same chromosomal location. Introns are noncoding sequences. Proteins are encoded by genes only; they are not a product of encouraged propagation caused by relative success in the functioning. So, the correct answer is option E.

Multiple choice biology adapting to a habit extreme adaptations adaptive features adaptations of organisms

Many tribes living in high altitudes of Himalayas have 

  1. High WBC count than people living in plains.

  2. Lower WBC count than people living in plains.

  3. Higher RBC count than people living in plains.

  4. Both RBC and WBC counts are lower than people living plains.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As the altitude increases, the atmospheric pressure decreases. Thus reducing the level of oxygen. People living at higher altitudes are used to the lower density of oxygen molecules in the air. They have higher levels of haemoglobin (red blood cells) in their blood which helps them to take in more oxygen. In contrast, people living at lower altitudes have lesser haemoglobin concentrations as they experience a higher density of oxygen molecules in the air.


So, the correct answer is 'C'.

Multiple choice biology immunity phagocytosis cells in immune system immune system, its cells, mediators and antigens

Phagocytosis

  1. Is carried by cells of the adaptive immune system

  2. Is restricted to macrophages

  3. Is important in bacterial infections

  4. Is a process that does not involve energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Phagocytosis is a process by which certain living cells called phagocytes ingest or engulf other cells or particles It is normally important in bacterial infections.

So, the correct option is 'is important in bacterial infections'

Multiple choice zoology immunity phagocytosis cells in immune system immune system, its cells, mediators and antigens

Life of the effector cells of immune system is 

  1. A few weeks to several years

  2. A few days

  3. A few years

  4. A few months to whole life
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Effector cells of the immune system, such as activated T-cells or plasma cells, typically have a short lifespan, often lasting only a few days to a few weeks before undergoing apoptosis.