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

Which antibodies could be detected on day 18 in both the strains of mice?

Directions: In an experiment on immune response of mice to allergens, dust mice allergen was exposed to two strains of mice – BALB/c mice (B) and Nude mice (N). The allergen was administered on day 0 and day 8 to both the strains of mice and allergen specific antibody produced was monitored and studied.

  1. Ig G (B) and Ig M (N)

  2. Ig E (B) and Ig E (N)

  3. Ig E (B) and Ig D (N)

  4. Ig A (B) and Ig G (N)

  5. both 2 and 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

On day 8, the allergen was again administered and thus it will create sensitization, resulting in release of the most predominant antibody Ig G, in case of BALB/c mice. The same will persist in case of nude mice.

Multiple choice

Consider the following statements. (a) Blood group O is the universal recipient. (b) Blood group AB is the universal donor. (c) A cross between tall plant with yellow seeds and tall plant with green seeds will produce three tall and green plants; one dwarf and green plant. (d) The antibodies anti A and anti B are called agglutinates. Which of the above statements is/are correct?

  1. Only (a)

  2. Only (b)

  3. Only (c)

  4. Only (d)

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

Statement (c) is correct. A cross between tall plant with yellow seeds and tall plant with green seeds will produce three tall and green plants; one dwarf and green plant.

Multiple choice

How does cellular immunity help in destroying pathogens?

  1. By activating immune system

  2. By activating antigens

  3. By activating compliment system

  4. By activating macrophages
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cellular immunity helps in protecting our bodies i. by activating antigen specific cytotoxic T-lymphocytes which are capable of inducing apoptosis within the body cells showing foreign antigen’s epitopes on their surface like virus-infected cells, cells having intracellular bacteria and cancer cells showing tumor antigens. ii. By activating macrophages and other normal killer cells causing them to kill pathogens and the stimulating cells for secreting number of cytokines which trigger other cells’ function associated in adaptive and innate immune response.

Multiple choice

” In cell mediated immunity, presence of cytokines are optional.”- What is the actual reason?

  1. Due to formation of antibodies against soluble antigens

  2. Due to B cell activation

  3. Due to formation of antibodies against insoluble antigens

  4. Death of cytotoxic T cell by apoptosis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Historically immune system was differentiated into two groups: humoral immunity where protective purpose of immunisation could be present in humor (cell free serum) and cellular immunity where protective purpose of immunisation was correlated with cells. CD4 cells or helper T cells protects against several pathogens. Due to death of cytotoxic T cells by apoptosis without the use of cytokines in the cell mediated immunity, presence of cytokines is optional.

Multiple choice

Humoral immunity defines the production of an antibody and associated processes that go with it involving Th2 activation and production of cytokines, formation of germinal centre and switching of isotype, affinity maturation and generation of memory cell. It also defines the antibody’s effector functions that involve neutralisation of pathogen and toxin, classical complement activation and elimination of pathogen.

“Acute haemolytic reaction causes fast destruction of donor red blood cells.”- How does it happen?

  1. Due to the defect in immune system

  2. Due to a clerical error

  3. Due to B cells functions

  4. Due to B cells activation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Incomplete blood transfusion results in a transfusion reaction that is done by humoral immune response. This form of reaction is known as acute haemolytic reaction that causes fast destruction (haemolysis) of donor red blood cells by the host antibodies. The reason is normally a clerical error (i.e. the faulty blood unit being provided to wrong patient). Symptoms include fever, chills, back pain and red urine (haemoglobinuria). Main complication is the release of haemoglobin due to red blood cells’ destruction causing acute renal failure.