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Q8(a):
Differentiate the following and give examples of each:
(a) Innate and acquired immunity
Solution :
1. Conceptual Framework and Definitions
Immunity is defined as the overall ability of the host organism to fight the disease-causing organisms conferred by the immune system. This system is categorized based on the temporal acquisition and specificity of the response.
2. Comparative Analysis: Innate vs. Acquired Immunity
| Characteristic | Innate Immunity | Acquired (Adaptive) Immunity |
|---|---|---|
| Nature | Non-specific; present at birth. | Specific; developed after exposure to a pathogen. |
| Speed of Response | Immediate response. | Delayed (Lag phase is required). |
| Memory | Lacks immunological memory. | Possesses immunological memory. |
| Components | Physical, Physiological, Cellular, Cytokine barriers. | B-lymphocytes (Antibodies) and T-lymphocytes. |
3. Granular Breakdown of Components
A. Innate Immunity (Non-specific Defense)
Innate immunity functions as the first and second line of defense, acting regardless of whether the pathogen has been previously encountered [Per Principle of Genetic Pre-programming].
- Physical Barriers: The skin (main barrier) and mucous coatings of the respiratory, gastrointestinal, and urogenital tracts.
- Physiological Barriers: Acid in the stomach, saliva in the mouth, and tears from eyes which prevent microbial growth [Per Biochemical Defense Mechanism].
- Cellular Barriers: Polymorphonuclear leukocytes (PMNL-neutrophils), monocytes, and natural killer (NK) cells in the blood.
- Cytokine Barriers: Interferons ($\alpha$-interferons) secreted by virus-infected cells which protect non-infected cells from further viral infection.
B. Acquired Immunity (Specific Defense)
Acquired immunity is pathogen-specific. It is characterized by its ability to distinguish between 'self' and 'non-self' and the secondary response which is highly intensified [Per Clonal Selection Theory].
- Humoral Immune Response: Mediated by antibodies produced by B-lymphocytes in response to pathogens circulating in blood/lymph.
- Cell-Mediated Immune Response (CMIR): Mediated by T-lymphocytes. This is responsible for graft rejection and the destruction of intracellular pathogens.
4. Graphical Representation of Immune Barriers
5. Illustrative Examples
- Example of Innate Immunity: The acidic environment of the stomach ($pH \approx 1.5 - 3.5$) that destroys ingested microorganisms, or the lysozyme enzyme present in tears that hydrolyzes bacterial cell walls.
- Example of Acquired Immunity: Vaccination (Active Acquired) or the production of specific antibodies against the Hepatitis B virus after an individual is exposed to the antigen, resulting in long-term memory cells.
Final Solution: Innate immunity is a non-specific, immediate defense system (e.g., skin, stomach acid) present from birth, whereas acquired immunity is a specific, memory-dependent defense system (e.g., B and T cell activation via vaccination) developed during an individual's lifetime.
More Questions from Class 12 Biology Human Health and Disease EXERCISES
- Q1: What are the various public health measures, which you would suggest as safeguard against infectious diseases?
- Q1: What are the various public health measures, which you would suggest as safeguard against infectious diseases?
- Q2: In which way has the study of biology helped us to control infectious diseases?
- Q2: In which way has the study of biology helped us to control infectious diseases?
- Q3(a): How does the transmission of each of the following diseases take place? (a) Amoebiasis
- Q3(a): How does the transmission of each of the following diseases take place? (a) Amoebiasis
- Q3(b): How does the transmission of each of the following diseases take place? (b) Malaria
- Q3(b): How does the transmission of each of the following diseases take place? (b) Malaria
- Q3(c): How does the transmission of each of the following diseases take place? (c) Ascariasis
- Q3(c): How does the transmission of each of the following diseases take place? (c) Ascariasis
- Q3(d): How does the transmission of each of the following diseases take place? (d) Pneumonia
- Q3(d): How does the transmission of each of the following diseases take place? (d) Pneumonia
- Q4: What measure would you take to prevent water-borne diseases?
- Q4: What measure would you take to prevent water-borne diseases?
- Q5: Discuss with your teacher what does ‘a suitable gene’ means, in the context of DNA vaccines.
- Q5: Discuss with your teacher what does ‘a suitable gene’ means, in the context of DNA vaccines.
- Q6: Name the primary and secondary lymphoid organs.
- Q6: Name the primary and secondary lymphoid organs.
- Q7(a): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (a) MALT
- Q7(a): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (a) MALT
- Q7(b): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (b) CMI
- Q7(b): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (b) CMI
- Q7(c): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (c) AIDS
- Q7(c): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (c) AIDS
- Q7(d): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (d) NACO
- Q7(d): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (d) NACO
- Q7(e): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (e) HIV
- Q7(e): The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form: (e) HIV
- Q8(a): Differentiate the following and give examples of each: (a) Innate and acquired immunity
- Q8(b): Differentiate the following and give examples of each: (b) Active and passive immunity
- Q8(b): Differentiate the following and give examples of each: (b) Active and passive immunity
- Q9: Draw a well-labelled diagram of an antibody molecule.
- Q9: Draw a well-labelled diagram of an antibody molecule.
- Q10: What are the various routes by which transmission of human immuno-deficiency virus takes place?
- Q10: What are the various routes by which transmission of human immuno-deficiency virus takes place?
- Q11: What is the mechanism by which the AIDS virus causes deficiency of immune system of the infected person?
- Q11: What is the mechanism by which the AIDS virus causes deficiency of immune system of the infected person?
- Q12: How is a cancerous cell different from a normal cell?
- Q12: How is a cancerous cell different from a normal cell?
- Q13: Explain what is meant by metastasis.
- Q13: Explain what is meant by metastasis.
- Q14: List the harmful effects caused by alcohol/drug abuse.
- Q14: List the harmful effects caused by alcohol/drug abuse.
- Q15: Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?
- Q15: Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?
- Q16: Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with your teacher.
- Q16: Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with your teacher.
- Q17: In your view what motivates youngsters to take to alcohol or drugs and how can this be avoided?
- Q17: In your view what motivates youngsters to take to alcohol or drugs and how can this be avoided?
CBSE Solutions for Class 12 Biology Human Health and Disease
Chapters in CBSE - Class 12 Biology
- Reproduction in Organisms
- Human Reproduction
- Reproductive Health
- Principles of Inheritance and Variation
- Molecular Basis of Inheritance
- Evolution
- Strategies for Enhancement in Food Production
- Microbes in Human Welfare
- Biotechnology: Principles and Processes
- Biotechnology and Its Applications
- Organisms and Populations
- Ecosystem
- Biodiversity and Conservation
- Environmental Issues
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