Class 12 Biology MCQ – Human Health – Innate and Acquired Immunity

This set of Class 12 Biology Chapter 8 Multiple Choice Questions & Answers (MCQs) focuses on “Human Health – Innate and Acquired Immunity”.

1. Which of the following barriers does not come under innate immunity?
a) Physical barrier
b) Physiological barrier
c) Complex barrier
d) Cellular barrier
View Answer

Answer: c
Explanation: Complex barrier does not come under innate immunity. Innate immunity includes Physical barrier, Physiological barrier, Cellular barrier and Cytokine barrier.

2. Which of the following barriers are considered to be the first line of defence in our body?
a) Physical and Physiological barriers
b) Physiological and Cellular barriers
c) Cellular and Cytokine barriers
d) Physical and Cellular barriers
View Answer

Answer: a
Explanation: Physical and physiological barriers are considered to be the first line of defence in our body. Cellular and Cytokine barriers form the second line of defence in our body.

3. Innate immunity is also called as ________
a) Specific immunity
b) Inborn immunity
c) Acquired immunity
d) Adapted immunity
View Answer

Answer: b
Explanation: Innate immunity is also called as inborn immunity because it is present at the time of birth. This is a non-specific type of defence. It is accomplished by providing different types of barriers to the entry of a foreign agent or a pathogen into our body.
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4. How many lines of defence are present in our body?
a) One
b) Two
c) Three
d) Four
View Answer

Answer: c
Explanation: Our body has three lines of defence. The first line of defence is Physical and Physiological barriers. The second line of defence includes Cellular and Cytokine barriers. The third line of defence includes humoral and cell-mediated immunity.

5. Acquired Immunity is not called as ___________
a) Specific Immunity
b) Adapted Immunity
c) Humoral Immunity
d) Non-specific Immunity
View Answer

Answer: d
Explanation: Acquired Immunity is not called as Non-specific Immunity. Acquired Immunity is also called as Specific Immunity and Adapted Immunity. Acquired Immunity is further divided into Humoral and Cell-Mediated Immunity.

6. Which of the following is not an Anatomic barrier?
a) Skin
b) Oil and sweat
c) Nostril hair
d) Mucus and cilia
View Answer

Answer: b
Explanation: Oil and sweat are not Anatomic or Physical barriers. Anatomic barriers are Skin, Nostril hair, Mucous membranes, Mucus and cilia.

7. Lysozyme is _________
a) Antiviral
b) Antiprotozoal
c) Antibacterial
d) Antifungal
View Answer

Answer: c
Explanation: Lysozyme is Antibacterial by nature. It is a bacteriolytic enzyme present in sweat, tears, saliva and mucus. Lysozyme brings about the hydrolysis of bacterial cell walls.

8. What is the full form of PMNL?
a) Polymorpho-nuclear leukocytes
b) Pinacocytes Mono-nuclear lymphocytes
c) Polynomial lymphocytes
d) Pinacoderm Mono-nuclear lymphocytes
View Answer

Answer: a
Explanation: PMNL-neutrophils are Polymorpho-nuclear leukocytes. These are granulocytes which are a category of white blood cells and have granules in their cytoplasm. They have a varying degree of the nucleus in their cells.

9. Which of the following are not the Phagocytes of innate immunity?
a) Neutrophils
b) Macrophages
c) RBCs
d) Monocytes
View Answer

Answer: c
Explanation: Phagocytosis is carried out by leucocytes and macrophages. The two-act as soldiers of defence and scavengers of the body. Phagocytic leucocytes are neutrophils and monocytes. Macrophages are also modified monocytes.
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10. Number of proteins belonging to the complementary system is _______
a) Ten
b) Sixty
c) Forty-Four
d) Thirty
View Answer

Answer: d
Explanation: Complement system is a system of over 30 proteins which participate in both innate and acquired immunities in a cascade fashion for protecting the individual from pathogens.

11. In innate immunity, complement system functions through ________
a) Alternate pathway
b) Classical pathway
c) Heightened pathway
d) Anatomical pathway
View Answer

Answer: a
Explanation: In innate immunity, complement system functions through the Alternate Pathway. The system gets activated directly in response to bacterial endotoxins, microbial polysaccharides, cell wall and other components of invading microorganisms.

12. Interferons are which type of barriers?
a) Physical barriers
b) Physiological barriers
c) Cellular barriers
d) Cytokine barriers
View Answer

Answer: d
Explanation: Interferons are a type of Cytokine barrier. They are a type of protein secreted by virus-infected cells which protect the non-infected cells from viral infection.

13. Which of the following response is not included in Acquired immunity?
a) Primary Response
b) Tertiary Response
c) Secondary Response
d) Anamnestic Response
View Answer

Answer: b
Explanation: Tertiary response is not included in Acquired immunity. When our body encounters a pathogen for the first time, it initiates a primary response. When the same pathogen enters our body again, memory B and T-cells will immediately start dividing to produce effector B and T cells. This is called as a Secondary or Anamnestic response.

14. In Acquired immunity, complement system functions through___________
a) Classical pathway
b) Alternate pathway
c) Heightened pathway
d) Anatomical pathway
View Answer

Answer: a
Explanation: In Acquired immunity, complement system functions through Classical pathway. In Acquired immunity, the system becomes active in response to the antigen-antibody complex.

15. Which of the following Cellular barriers are involved in Inflammatory reactions?
a) Neutrophils
b) Basophils
c) Eosinophils
d) Monocytes
View Answer

Answer: b
Explanation: Basophils are involved in inflammatory reactions. Neutrophils and Monocytes show Diapedesis and Phagocytosis. Eosinophils are involved in allergy and parasitic infections.

Sanfoundry Global Education & Learning Series – Biology – Class 12.

To practice all chapters and topics of class 12 Biology, here is complete set of 1000+ Multiple Choice Questions and Answers.

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