Immunity in Humans questions

Which of the following could be a reason for the number of red blood cells dropping below the normal level?

1. A Overactivity of the bone marrow
2. B Overactivity of the spleen
3. C Underactivity of the thymus gland
4. D An increase in the number of natural killer cells

Which of the following systems is the most similar to the lymphatic system in how its organs are anatomically connected to each other?

1. A The digestive system
2. B The circulatory system
3. C The skeletal system
4. D The endocrine system

Which of the following statements does NOT describe structure (X) correctly?

1. A It contains lymphatic stem cells
2. B Maturation and differentiation of some immune cells
3. C It produces all types of white blood cells
4. D It stores lymphocytes

In which of the following lymphatic organs do lymphocytes acquire their immune ability?

1. A Peyer's patches and the tonsils
2. B The bone marrow and the thymus gland
3. C The bone marrow only
4. D The thymus gland only

Which of the following statements is NOT correct about the structure shown in the opposite figure?

1. A It contains white blood cells
2. B It produces lymphocytes
3. C It is a source of iron supply for the body
4. D It is a secondary lymphatic organ

Which of the following is a primary lymphatic organ and structurally belongs to another system in the human body?

1. A The appendix
2. B The spleen
3. C Peyer's patches
4. D The thymus gland

During the embryonic stages, blood cells are produced by the liver and the spleen. As the embryo develops, this function moves to the ..........

1. A thymus gland
2. B bone marrow
3. C lymph nodes
4. D tonsils

If you know that an artery carries blood to an organ while a vein carries blood away from the organ, which of the structures in the opposite figure do NOT contain lymphatic stem cells?

1. A (X) only
2. B (Y) only
3. C (X) , (Z)
4. D (Y) , (Z)

The opposite diagram shows a cross section in the abdominal region. Which of the following is correct about structure (X)?

1. A It contains the basic components of red blood cells
2. B It helps in the differentiation of lymphocytes
3. C It belongs to the circulatory system
4. D It belongs to the digestive system

Which of the following stores most types of immune cells?

1. A The appendix
2. B The lymph nodes
3. C Peyer's patches
4. D The thymus gland

Study the opposite diagram, then deduce:
What do the numbers (1), (2), (3) represent, respectively?

1. A Afferent lymph vessel / lymph node / vein
2. B Artery / lymph node / vein
3. C Efferent lymph vessel / lymph node / afferent lymph vessel
4. D Afferent lymph vessel / lymph node / efferent lymph vessel

Study the opposite diagram, then deduce:
Which of the following substances represent (X), (Y), (Z), respectively?

1. A Glucose / pure plasma / CO2
2. B Oxygen / impure lymph / nitrogenous wastes
3. C Glucose / pure blood / CO2
4. D Oxygen / impure lymph / pure lymph

Which of the following is NOT correct about the tonsils?

1. A They protect the respiratory and digestive systems
2. B They contain white blood cells
3. C They are secondary lymphatic organs
4. D They are primary lymphatic organs

In the opposite figure, which of the following statements is correct about structure (X)?

1. A A structure in the digestive system that takes part in the work of the lymphatic system
2. B A structure in the lymphatic system that takes part in the work of the digestive system
3. C A structure in the lymphatic system that helps protect the digestive system
4. D A structure shared between the digestive and respiratory systems

Which of the following graphs is correct for a lymph node?

1. A A
2. B B
3. C C
4. D D

Which of the following is NOT one of the main functions of the lymphatic system?

1. A Producing lymphocytes
2. B Filtering lymph from microbes
3. C Regulating body temperature
4. D Storing lymphocytes

Some children are born with severe combined immunodeficiency (SCID), a rare genetic disease in which the body lacks lymphocytes and cannot fight even simple diseases. How can these children be treated?

1. A Bone marrow transplant
2. B Continuous use of antibiotics
3. C Injection with antibodies
4. D Vaccination against all diseases

The opposite figure shows the lymphatic system in humans. Which of the following lymphatic organs have a direct role in killing the harmful bacteria that enter the body when a contaminated meal is eaten?

1. A (1) only
2. B (2) only
3. C (1) , (4)
4. D (2) , (3) , (4)

Which of the following statements is correct about the thymus gland?

1. A It is an exocrine (duct) gland
2. B It is a mixed gland
3. C It belongs to the lymphatic system and the endocrine system
4. D It secretes a hormone that affects the bone marrow

Which lymphatic organ is called the graveyard of red blood cells?

1. A The spleen
2. B The bone marrow
3. C The thymus gland
4. D The tonsils

Which of the following cells have receptors for the hormone thymosin on their plasma membranes?

1. A Thymus gland cells
2. B Helper T cells
3. C Mature B cells
4. D Lymphatic stem cells

Which of the following does NOT apply to lymphocytes?

1. A They originate in the red bone marrow
2. B All of them mature in the thymus gland
3. C Some of them suppress the immune response
4. D They become active in the presence of the microbe

Which of the following cells activate both B cells and T cells?

1. A Activated B cells
2. B Cytotoxic T cells
3. C Natural killer cells
4. D Helper T cells

Why are T lymphocytes given this name?

1. A They are produced in the bone marrow
2. B They mature in the thymus gland
3. C They are stored in the lymph nodes
4. D They flow in the lymph

The opposite graph shows the percentages of the types of lymphocytes in a blood sample. Which of them produce antibodies?

1. A (X) only
2. B (Z) only
3. C (X) , (Y)
4. D (Y) , (Z)

Which of the following immune cells has a multilobed nucleus?

1. A Lymphocytes
2. B Monocytes
3. C Eosinophils
4. D Neutrophils

Which of the following lymphocytes has no immune role against microbes?

1. A (B) cells
2. B (TH) cells
3. C (TC) cells
4. D (TS) cells

Which of the following cells are granular?

1. A Monocytes
2. B T cells
3. C B cells
4. D Mast cells

Which of the following cells are non-granular and non-specific?

1. A T cells
2. B B cells
3. C Natural killer cells
4. D Mast cells

Which of the following white blood cells can change into another type of immune cell?

1. A Lymphocytes
2. B Monocytes
3. C Eosinophils
4. D Neutrophils

Which of the following is NOT affected by cytotoxic T cells?

1. A A transplanted liver lobe
2. B Cancer cells
3. C Toxins secreted by bacteria
4. D Cells infected with the influenza virus

Which of the following lymphocytes become active when toxins enter the body?

1. A B cells
2. B Natural killer cells
3. C Cytotoxic T cells
4. D Mast cells

Which of the following cells secrete the enzymes that break down hemoglobin (the protein of red blood cells)?

1. A B cells
2. B Natural killer cells
3. C Macrophages
4. D Suppressor T cells

If the number of lymphocytes in a drop of blood is 8000 cells / mm³, what is the average number of the cells responsible for producing antibodies?

1. A 400
2. B 1000
3. C 1200
4. D 6400

Study the opposite figure, then answer:
What does cell (X) represent?

1. A Macrophage
2. B Monocyte
3. C Neutrophil
4. D Eosinophil

Study the opposite figure, then answer:
What are processes (1), (2) called, respectively?

1. A Digestion / endocytosis
2. B Nutrition / digestion
3. C Exocytosis / engulfing
4. D Engulfing / digestion

Which of the following is NOT a phagocytic cell?

1. A Macrophages
2. B Mast cells
3. C Basophils
4. D Eosinophils

The following figures show some types of blood cells. Which of the following choices represents cells (1) to (4), respectively?

1. A Phagocytic cell / red blood cell / macrophage / lymphocyte
2. B Macrophage / phagocytic cell / red blood cell / lymphocyte
3. C Lymphocyte / phagocytic cell / red blood cell / macrophage
4. D Macrophage / phagocytic cell / lymphocyte / red blood cell

Which of the following pairs have opposite effects to each other?

1. A T cells and B cells
2. B Plasma cells and memory cells
3. C Helper T cells and suppressor T cells
4. D Natural killer cells and macrophages

If the average number of B cells in a person's drop of blood is about 400 cells, what is the average number of T cells in the same drop of blood?

1. A 1000
2. B 1500
3. C 2000
4. D 2500

Neutrophils are classified as ..........

1. A granular and specific
2. B granular and non-specific
3. C non-granular and specific
4. D non-granular and non-specific

Red blood cells were transferred from a vertebrate to another vertebrate of the same species after making sure their blood was compatible. If the number of lymphocytes in the spleen of the receiving animal before the injection was about 5 thousand cells, what will the number of lymphocytes be one week after the injection?

1. A Zero
2. B 5 thousand
3. C 10 thousand
4. D 20 thousand

Which of the following is correct about lymphocytes?

1. A All of them are granular cells
2. B All of them mature in the same lymphatic organ
3. C All of them are formed in the same lymphatic organ
4. D All of them mature under a hormonal effect

What immune role do complement proteins play?

1. A Engulfing the pathogen
2. B Attracting phagocytic cells
3. C Linking the different cells of the immune system
4. D Making it easier to engulf the pathogen

Which cells must be present for complement proteins to do their work?

1. A TC
2. B TS
3. C NK
4. D Plasma B cells

Detoxification enzymes in plants correspond in humans to ..........

1. A complement proteins
2. B chemokines
3. C interferons
4. D interleukins

What do compounds (X) in the opposite figure represent?

1. A Lymphokines
2. B Cytokines
3. C Complement proteins
4. D Chemokines

From the opposite figure, which of the following describes compounds (X)?

1. A Chemokines that attract phagocytic cells
2. B Interleukins that bind to healthy living cells
3. C Interferons that prevent viruses from multiplying
4. D Complement proteins that break down the virus envelope

Which of the following is a property of interferon?

1. A A protective substance
2. B A specific protein
3. C A toxic substance
4. D A digestive protein

Which chemical substances may be used to inhibit the activity of the hepatitis (C) virus in liver tissues?

1. A Chemokines
2. B Interleukins
3. C The complement series
4. D Interferons

The two opposite figures show the structure of an antibody. In what are the building units of part (A) and part (B) similar?

1. A Their sequence
2. B Their types
3. C Their 3D shape
4. D The type of chemical bonds in them

From the following table, which choice describes the antigen and the antibody correctly?

1. A Antigen: made of amino acids / Antibody: made of fatty acids
2. B Antigen: varied in shape and structure / Antibody: identical in shape and structure
3. C Antigen: a substance foreign to the body / Antibody: an immune response in the body
4. D Antigen: found outside cells / Antibody: found inside cells

Which of the following statements is NOT correct about the antibody (IgG)?

1. A The variable region of the heavy chain is partly responsible for binding to the antigen
2. B The variable region of the light chain is partly responsible for binding to the antigen
3. C The hinge region binds to the antigen of the pathogen
4. D It has two identical antigen-binding sites

If plasma (B) cells produce about 2 million antibodies of the IgG type daily, and these break down within 3 weeks, what is the maximum number of antigens these antibodies can bind to within one week?

1. A 4 million
2. B 7 million
3. C 14 million
4. D 28 million

Types of antibodies differ from each other in ..........

1. A the place where the cells that produce them are formed
2. B the place where the cells that produce them mature
3. C the types of bonds in each of them
4. D the order of the amino acids in each of them

What stimulates the formation of antibodies?

1. A The response to a particular antigen entering the blood
2. B An increase in the activity of cytotoxic T cells
3. C A decrease in the activity of B cells
4. D A lack of the thymus gland hormone

How does the antibody that contains chain (1) differ from the antibody that contains chain (2)?

1. A The number of amino acids
2. B The number of peptide bonds
3. C The order of the amino acids
4. D The types of amino acids

Which of the following is NOT a property of the antibody (IgM)?

1. A It has 10 antigen-binding sites
2. B It has 10 heavy protein chains
3. C It has 5 hinge regions
4. D It contains peptide bonds

In the opposite figure, which of the following is an incorrect description of part (X)?

1. A It is an easy target for phagocytic cells
2. B The antigen-antibody complex is formed
3. C The antibody dissolves the antigen
4. D It prevents the antigen from harming the cell

What is the direct aim of the action of the antibodies in the opposite figure?

1. A Getting rid of the metabolic toxins of the microbe
2. B Restricting the microbe
3. C Carrying out phagocytosis
4. D Producing memory cells to fight this microbe

In the opposite figure, how many pairs of antigen-binding sites are there?

1. A 2
2. B 4
3. C 5
4. D 10

Which of the following figures shows the stage at which the cell secretes interferons?

1. A A
2. B B
3. C C
4. D D

From the opposite figure, how many types of antibodies can bind to this bacterial cell?

1. A 1
2. B 15
3. C 3
4. D 18

Using the following figures, if (X) and (Z) are both found in the blood plasma of a vertebrate, and (Y) is a pathogen of this organism, what do you expect to happen?

1. A Both (X) and (Y) bind to (Z)
2. B Both (Y) and (Z) bind to (X)
3. C Both (X) and (Z) bind to (Y)
4. D None of them binds to another

From the opposite figure, which shows the structure of an antibody:
Which of the following parts allows the distance between the two antigen-binding sites to change?

1. A X
2. B Y
3. C Z
4. D L

From the opposite figure, which shows the structure of an antibody:
Which of the following structures is the specificity of the antibody due to?

1. A X
2. B Y
3. C Z
4. D L

Which of the following substances are found in blood and lymph and can recognize the antigen and bind to it?

1. A Interleukins
2. B Complement proteins
3. C Antibodies
4. D Chemokines

How is the body protected from the pathogen shown in the figure in front of you?

1. A Structure (X) binds to the constant region of the antibody
2. B Structure (Y) binds to the antigen-binding site of the antibody
3. C A complex forms from structure (X) and the antibody
4. D A complex forms from structure (X) and complement proteins

If a plasma B cell produced 2 million antibodies of the IgM type, how many light chains are needed to form them?

1. A 2 million
2. B 4 million
3. C 10 million
4. D 20 million

Which of the following statements is correct?

1. A B cells are found in the lymph nodes only
2. B Antibodies are active in blood plasma and in the cytoplasm of cells
3. C Antibodies neutralize the spread of viruses
4. D Interferons inhibit the enzymes that copy the viral nucleic acid in the infected cell

Where does the process shown in the opposite figure take place?

1. A In the blood only
2. B In the lymph only
3. C In the red bone marrow and the lymph
4. D In the blood and the lymph

To make phagocytosis easier, which of the following must be present?

1. A Antigens only
2. B Antibodies only
3. C Antigens and complement proteins only
4. D Antigens bound to antibodies that are attached to complement proteins

Which of the following statements is NOT correct about the properties of the antibody?

1. A One antibody can bind to more than one antigen
2. B More than one antibody can bind to one microbe
3. C Antibodies are always bivalent (two binding sites)
4. D Antibodies enhance phagocytosis

Which of the cases shown in the following figures represents a blood sample in which macrophages become active?

1. A A
2. B B
3. C C
4. D D

Which of the following graphs is correct?

1. A A
2. B B
3. C C
4. D D

To treat a person bitten by a poisonous snake, which of the following substances is it better to inject him with?

1. A Interferons
2. B Antibodies
3. C Interleukins
4. D Chemokines

Study the following diagram, which shows some stages that a type of lymphocyte goes through in the human body, then state:
(1) What do cells (Y) and (L) refer to?
(2) What do stages (1) and (2) refer to?

The opposite graph shows the development of the immune ability of one type of white blood cell, which makes up most of the lymphocytes. Where does stage (1) take place?

A person was exposed to radiation that destroyed the red bone marrow and the thymus gland, then he had a new bone marrow transplant. Which cells will not take part in the immune response when the person is infected with a microbe? Explain your answer.

From the opposite diagram, what can be concluded about the function of this organ?

Study the opposite figure, which shows the percentages of the types of lymphocytes in human blood:
(1) State the symbol that refers to:
(a) Cells that are formed in the bone marrow and mature in the thymus gland.
(b) Cells that are able to produce antibodies.
(2) What immune substances do cells (B) secrete?

The opposite figure represents one of the immunoglobulins:
(1) What is the number of the variable part of the long chain?
(2) What is the number of the part that activates the lysis reactions?
(3) What is the number of the part which, if broken, splits the antibody into two halves, each the mirror image of the other?
(4) What happens if the amino acid sequence in region (4) changes?

The opposite figure shows the stages of a virus attacking a cell and multiplying inside it:
(1) In which of these stages will the antibody have no role in protecting the cell from this virus? Explain your answer.
(2) Which of these stages will be affected by the presence of interferons? Explain your answer.

The following figures show one of the mechanisms of antibody action:
(1) What does this mechanism represent?
(2) In which case can this mechanism happen?
(3) What does the cell marked with the symbol (X) represent?

The opposite graph shows the development of the immune ability of one type of white blood cell, which makes up most of the lymphocytes. Where does stage (2) take place? (1st session 2021)

1. A The thymus gland
2. B The lymph node
3. C The bone marrow
4. D The spleen

Study the following diagram, which shows the stages of forming one type of lymphocyte in the human body, then state:
What do symbols (X) and (Z) refer to, respectively? (2nd session 2021)

1. A The thymus gland / the bone marrow
2. B The bone marrow / the spleen
3. C The bone marrow / the thymus gland
4. D The thymus gland / the spleen

In which of the following embryonic stages does the formation of lymphocytes begin? (1st session 2022)

1. A At the moment of fertilization
2. B The second
3. C The third
4. D At the moment of birth

Study the opposite diagram, which shows the role of a lymph node in the human body. What is the relation between the components of the two fluids (X) and (Y)? (1st session 2022)

1. A The number of white blood cells in each of them is equal
2. B There are no white blood cells in (Y)
3. C The number of white blood cells in (X) is less than in (Y)
4. D There is no relation between the number of white blood cells in each of them

What is the result of removing the spleen? (Trial exam 2023, Sample exam 2025)

1. A A decrease in the number of memory cells in the blood
2. B An increase in the number of old red blood cells in the blood
3. C Inability to produce antibodies
4. D The thymus gland cannot differentiate lymphocytes

What is the similarity between the bone marrow and the thymus gland? (1st session 2023)

1. A Trapping foreign bodies
2. B Forming lymphocytes
3. C Maturation of lymphocytes
4. D Storing basophils

If you know that the protein hemoglobin is formed by amino acids binding to the element iron, study the opposite diagram, then state the function of the lymphatic organ as the diagram shows. (2nd session 2023)

1. A Destroying red blood cells
2. B Destroying white blood cells
3. C Producing new red blood cells
4. D Producing antibodies

Which of the following lymphatic organs structurally belongs to another system of the human body in addition to being a lymphatic organ? (1st session 2024)

1. A The spleen
2. B The thymus gland
3. C The lymph nodes
4. D The tonsils

Which of the following is NOT a function of the lymphatic organs? (1st session 2024)

1. A Producing immune cells
2. B Storing immune cells
3. C Maturation and differentiation of immune cells
4. D Protecting immune cells

Which of the following is the most important lymphatic organ? (2nd session 2024)

1. A The bone marrow
2. B The spleen
3. C The thymus gland
4. D The tonsils

For which of the following white blood cells is the organ in front of you NOT a home? (2nd session 2024)

1. A Neutrophils
2. B B cells
3. C T cells
4. D Natural killer cells

What is the similarity between the spleen and the lymph nodes? (Sample exam 2025)

1. A They take part in forming lymphocytes
2. B They take part in the maturation of lymphocytes
3. C They take part in storing lymphocytes
4. D They take part in producing different types of blood cells

From the following diagram, if (X) and (Y) are two types of lymphocytes: (2nd session 2025)
Which of the following statements describes cells (Y) correctly?

1. A One type of specific cells
2. B Two types of specific cells
3. C Three types of specific cells
4. D Two types of specific cells and one type of non-specific cells

Which of the following bones produce immune cells in an adult? (Sample exam 2026)

1. A The phalanges
2. B The tarsals
3. C The carpals
4. D The sternum

Which of the following immune organs can protect the beginning of the alimentary canal and part of its end? (Sample exam 2026)

1. A The spleen and Peyer's patches
2. B The thymus gland and the salivary glands
3. C The tonsils and Peyer's patches
4. D The tonsils and the stomach

From the two opposite figures, what is the type of immune cells in each of (1) and (2), respectively? (Trial exam / May 2021)

1. A Monocyte / cytotoxic (Tc)
2. B Macrophage / cells with granular cytoplasm
3. C Helper T (TH) / natural killer (NK)
4. D Natural killer (NK) / helper T (TH)

Which of the following cells does NOT increase in number in a person who has cancer? (Trial exam / June 2021)

1. A Natural killer
2. B Cytotoxic
3. C B cells
4. D Helper T

Study the opposite figure, which shows the percentages of the types of lymphocytes in human blood. Which symbol refers to cells whose work is linked to the presence of complement proteins? (1st session 2021)

1. A (A) and (C)
2. B (B) and (C)
3. C (B)
4. D (A)

Study the opposite figure, which shows some types of immune cells, then deduce the type of the immune cell marked with the letter (C). (1st session 2023, Sample exam 2025)

1. A Monocyte
2. B Lymphocyte
3. C Eosinophil
4. D Basophil

What property is shared by the immune cells that attack cancer cells? (2nd session 2023)

1. A The place where they mature
2. B The place where they are formed
3. C Having the same receptors on their surface
4. D Having granules in their cytoplasm

What is the reason for the failure of a liver lobe transplant in a person? (Sample exam 2025)

1. A Natural killer cells attack the transplanted cells
2. B Antibodies attack the transplanted cells
3. C Macrophages engulf the transplanted cells
4. D Basophils destroy the transplanted cells

Which immune cells are NOT formed in the bone marrow? (1st session 2025)

1. A Monocytes
2. B Memory T cells
3. C B cells
4. D Natural killer cells

Which of the following cells mature after leaving the red bone marrow? (Sample exam 2026)

1. A Mast cells
2. B Eosinophils
3. C Natural killer cells
4. D Helper T cells

Which of the following is NOT a component of the immune system? (Sample exam 2026)

1. A Red blood cells
2. B The spleen
3. C White blood cells
4. D The tonsils

Study the two opposite figures, then deduce what substance (X) is. (Trial exam / May 2021)

1. A Interferons
2. B Chemokines
3. C Interleukins
4. D Histamine

Which of the following is NOT a component of the immune system in humans? (Trial exam / June 2021)

1. A Antibodies
2. B Complement proteins
3. C Interferons
4. D Antigens

Study the opposite figure, which shows a group of cells that secreted a group of chemical substances, then state what substances (X) and (Y) are, respectively. (2nd session 2022)

1. A Chemokines / antibodies
2. B Complement proteins / antibodies
3. C Enzymes copying the genetic material / interferons
4. D Interferons / enzymes

Complement proteins complete the work of which component of the immune system? (1st session 2025)

1. A All types of phagocytic cells
2. B The helper chemical substances
3. C B cells and T cells
4. D Antibodies

The figure in front of you shows the structure of one of the components of the immune system. Which figure describes regions (A) and (B)? (Trial exam / May 2021)

1. A A
2. B B
3. C C
4. D D

The opposite figure shows the structure of one of the components of the immune system. What is the result of replacing one amino acid with another in region (A)? (Trial exam / May 2021)

1. A It becomes unsuitable for its own antigen
2. B It can bind to its own antigen
3. C No change happens to it
4. D A change happens in its own antigen

The following stages show one of the mechanisms of antibody action:
What most distinguishes this mechanism from the other mechanisms of antibody action? (Trial exam / June 2021)

1. A It needs the presence of complement proteins
2. B It happens only with one type of antibody
3. C It does not need the work of macrophages
4. D Whether it happens depends on the nature of the antigen

What immune role do cells infected with viruses whose genetic content is RNA play inside the human body? (Trial exam / June 2021)

1. A Secreting enzymes that kill pathogens inside the cells
2. B Producing chemical substances that are toxic to the pathogen
3. C Stimulating plasma B cells to form antibodies
4. D Secreting protein substances that stimulate the neighbouring healthy cells

Look at the opposite figure, which shows the structure of one half of an antibody in human blood. Identify structures (X), (Y), (Z), (L), then state the symbol of the structural part that distinguishes this type of antibody from the other globulins. (1st session 2021)

1. A (X)
2. B (Y)
3. C (Z)
4. D (L)

Study the figure in front of you, then state which sites help break down the antigens of compound (1). (2nd session 2021)

1. A (4) only
2. B (2) only
3. C (2) , (3)
4. D (3) , (5)

The opposite figure shows the structure of an antibody. Deduce which mechanisms cannot be completed using this antibody. (2nd session 2021)

1. A Agglutination and neutralization
2. B Neutralization and precipitation
3. C Lysis and neutralizing toxins
4. D Agglutination and precipitation

In front of you are four different antibodies. If you know that the parts shaded in black had a change in the sequence of the chain:
Which of the following represents the antibody that does its work efficiently? (1st session 2022)

1. A (X)
2. B (Y)
3. C (Z)
4. D (L)

Look at the opposite figure, which shows the structure of one type of antibody in human blood. Identify it, then deduce:
(1) What type of chains is site (X) made of? (2nd session 2022)

1. A The long constant
2. B The short and the long constant
3. C The short and the long variable
4. D The long variable

Look at the opposite figure, which shows the structure of one type of antibody in human blood. Identify it, then deduce:
(2) What is the chemical structure of the substance that (Y) is made of? (Trial exam 2023)

1. A Sulfur
2. B Sugars
3. C Proteins
4. D Steroids

The opposite figure shows the stages of a virus multiplying inside a human body cell. In which stage can the antibody work? (2nd session 2022)

1. A (1)
2. B (2)
3. C (3)
4. D (4)

Study the following figures, then state:
Which of the antibodies above helps destroy the toxins resulting from infection with a type of bacteria? (2nd session 2022)

1. A (1)
2. B (2)
3. C (3)
4. D (4)

Study the opposite figure, then deduce which structure is NOT represented by the letter (A). (1st session 2023, Sample exam 2025)

1. A The antigen-binding site
2. B The antigen
3. C The antibody-binding site
4. D A protein on the surface of the pathogen

Which of the following immune cells will work with complement proteins to break down microbes and engulf them? (1st session 2024)

1. A Plasma B cells only
2. B Macrophages only
3. C Plasma B cells and macrophages
4. D Plasma B cells, cytotoxic T cells and macrophages

Antibodies have the same chemical structure as the receptors of .......... cells. (Sample exam 2025)

1. A plasma
2. B B
3. C helper T
4. D T and B

In which of the following ways of antibody action do complement proteins take part? (1st session 2025)

1. A Neutralization and lysis
2. B Lysis and neutralizing toxins
3. C Neutralization and precipitation
4. D Precipitation and agglutination

Which of the following is NOT a component of the antibody? (2nd session 2025)

1. A The complement-binding site
2. B The antigen
3. C The antigen recognition site
4. D The hinge regions

The opposite figure represents an antibody. Which of the following is constant in structure and shape in all antibodies? (Sample exam 2026)

1. A (X)
2. B (Y)
3. C (Z)
4. D (L)

The opposite figure represents a 3D antibody. Which of the following figures represents the antigen? (Sample exam 2026)

1. A A
2. B B
3. C C
4. D D

Study the opposite figure, then deduce: (Trial exam 2023)
(1) What chemical bonds are found in region (VH)?
(2) What type of building units take part in forming the disulfide bonds between the two heavy chains of the molecule?

Study the following figure, which shows two different types of antibodies, then answer: (1st session 2024)
(1) What is the chemical difference between region (X) and region (Y)?
(2) How many types of plasma B cells produced these antibodies?

Study the opposite figure, which shows one of the mechanisms of antibody action, then deduce: (2nd session 2024)
(1) What type of pathogen can be eliminated using this mechanism?
(2) What does the symbol (Z) refer to?