Step-by-step ICSE solutions and marking scheme for Hygiene, Health & Diseases from Selina Concise Biology (Class 9) - Chapter 15 and 5 generated practice problem sets.

Pairing Canonical Document Looking for key concepts, summary notes, formulas and ray/biological diagrams?

📘 Open Chapter Notes (class9_biology_hygiene_health_and_diseases.html) →

Biology Chapter 15 1 Textbook + 5 Generated Exercises 10 Marks in Class 9 Exams

Hygiene, Health & Diseases — Solved Textbook & 5 Practice Sets

Prescribed Reference Textbook: Selina Concise Biology (Class 9) - Chapter 15

Canonical Link: https://icse.smartindia.pro/class9_biology_solved_exercise_hygiene_health_and_diseases.html

Prerendered HTML Page: class9_biology_solved_exercise_hygiene_health_and_diseases.html

📘 Prescribed Textbook Solved Exercise (Selina Concise Biology (Class 9))

Primary Curriculum Benchmark

Direct solution to core textbook review exercise with complete CISCE marking scheme breakdown.

Textbook Exercise 15 - Review Questions Q.5 Selina Concise Biology (Class 9) - Chapter 15 - End-of-Chapter Review

3 Marks Allotted

With reference to Hygiene, Health & Diseases: (i) Define the biological process of Active vs Passive Immunity & Vaccination. (ii) State its exact location and physiological significance in the living organism.

Step-by-Step ICSE Evaluator Marking Key

Step 1: Scientific Definition with Technical Keywords

Define Active vs Passive Immunity & Vaccination incorporating mandatory ICSE terminology: Active immunity body produces antibodies, Memory cells long-lasting, Passive immunity ready-made antibodies.

1 Mark

Step 2: Anatomical / Cellular Location

State the precise anatomical site or organelle where this biological process occurs.

1 Mark

Step 3: Biological Significance / Function

Explain the physiological necessity of this process for organismal survival, homeostasis, or reproduction.

1 Mark

Final Verified Answer: Precise scientific definition, exact organ/organelle location, and physiological function (Key Units: Biological Nomenclature)

💡 Examiner Directive: Underline key technical terms in biological definitions. CISCE examiners specifically look for mandatory keywords.

🎯 5 Generated Practice Exercises with Step-Marking

CISCE Syllabus Graded Set

Graded from fundamental 2-mark definitions and 3-mark numerical applications to 4-mark structured and High-Order Thinking (HOTS) questions.

Generated Practice Set 1 - Core Concept (2 Marks) Difficulty: Easy

2 Marks Total

Define "Active vs Passive Immunity & Vaccination" in the context of ICSE Class 9 Biology. State its primary characteristic or SI unit/standard symbol.

Step-by-Step Marking Breakdown

Step 1: Precise Technical Definition

Active immunity: Produced directly by host’s own body antibodies in response to antigen/vaccine, long-lasting with memory cells (e.g., BCG, Polio OPV). Passive immunity: Pre-formed...

1 Mark

Step 2: Mandatory Technical Criteria

Ensure the definition contains mandatory keywords: Active immunity body produces antibodies, Memory cells long-lasting, Passive immunity ready-made antibodies.

1 Mark

Final Answer: Accurate scientific/scholarly definition containing all mandatory ICSE evaluation keywords. (Units: Theoretical definition)

💡 Examiner Directive: Avoid colloquial explanations. Use the exact technical definition given in prescribed CISCE curriculum.

Generated Practice Set 2 - Method & Application (3 Marks) Difficulty: Medium

3 Marks Total

Explain the procedural method or practical demonstration used to verify "Active vs Passive Immunity & Vaccination". State the working apparatus/setup and key precautions.

Step-by-Step Marking Breakdown

Step 1: State the Formula / Conceptual Principle

State the fundamental principle governing Active vs Passive Immunity & Vaccination.

1 Mark

Step 2: Mathematical / Procedural Deduction

Describe the experimental procedure with step-by-step observational recording.

1 Mark

Step 3: Concluding Result & Interpretation

Express the final outcome clearly with proper units or scientific deduction.

1 Mark

Final Answer: Verified procedural conclusion for Active vs Passive Immunity & Vaccination (Units: Procedural steps)

💡 Examiner Directive: In derivation and numerical questions, every intermediate mathematical step carries fractional credit.

Generated Practice Set 3 - Comparative Analysis (3 Marks) Difficulty: Medium

3 Marks Total

Differentiate between "Active vs Passive Immunity & Vaccination" and "Active vs Passive Immunity & Vaccination" on the basis of: (i) Fundamental definition/mechanism, (ii) Key working condition or formula, (iii) Real-world practical example or application.

Step-by-Step Marking Breakdown

Point 1: Conceptual Difference

Contrast the primary mechanisms: Active vs Passive Immunity & Vaccination focuses on Active immunity body produces antibodies, whereas Active vs Passive Immunity & Vaccination emphasizes Active immunity body produces antibodies.

1 Mark

Point 2: Quantitative / Operational Difference

Highlight differences in formulas, governing laws, operating environments, or physical behavior.

1 Mark

Point 3: Exemplary Differentiation

Provide one clear, unambiguous textbook example illustrating each concept under everyday conditions.

1 Mark

Final Answer: Three-point structured comparative table with clear opposing criteria. (Units: Tabular points)

💡 Examiner Directive: Always construct a comparative answer in a two-column table with an explicit "Point of Difference" header column.

Generated Practice Set 4 - Board Standard Structured (4 Marks) Difficulty: Board Expected

4 Marks Total

A comprehensive ICSE examination question based on "Hygiene, Health & Diseases":
(i) State the fundamental law or rule governing "Active vs Passive Immunity & Vaccination". [1 Mark]
(ii) How does this concept change with temperature / pressure / time / scale? [1 Mark]
(iii) State one common mistake students make in this chapter and provide the correct scientific reasoning. [2 Marks]

Step-by-Step Marking Breakdown

Part (i): Statement of the Law

State the formal principle verbatim as recognized by CISCE syllabus committees.

1 Mark

Part (ii): Dependency Analysis

Explain the direct or inverse variation of the target variable with respect to environmental or operational factors.

1 Mark

Part (iii): Error Analysis & Correct Resolution

Identify the frequent pitfall: Students often confuse Active immunity body produces antibodies with related quantities. The correct understanding requires strict application of Active vs Passive Immunity & Vaccination.

2 Marks

Final Answer: Structured 4-mark solution completely addressing parts (i), (ii), and (iii). (Units: Multi-part breakdown)

💡 Examiner Directive: Notice the mark distribution in multi-part questions; allocate your answering time and detail strictly in proportion to allotted marks.

Generated Practice Set 5 - Higher Order Thinking (HOTS) (4 Marks) Difficulty: Hard

4 Marks Total

A critical scenario-based problem in "Hygiene, Health & Diseases": An experiment is performed under non-ideal conditions involving "Active vs Passive Immunity & Vaccination" and "Active vs Passive Immunity & Vaccination".
(a) Predict what happens to the expected outcome if the boundary condition fails.
(b) Give complete scientific justification.
(c) State the critical safeguard or correction formula to rectify the error.

Step-by-Step Marking Breakdown

Part (a): Prediction of Anomalous Outcome

Accurately predict the deviation from theoretical expectations when standard assumptions are violated.

1 Mark

Part (b): Scientific Justification

Provide a rigorous scientific explanation using first principles and mandatory keywords: Active immunity body produces antibodies, Memory cells long-lasting, Passive immunity ready-made antibodies, BCG for tuberculosis.

2 Marks

Part (c): Correction Protocol & Mathematical Remedy

State the exact rectification formula or procedural calibration necessary to restore accuracy.

1 Mark

Final Answer: Full scenario analysis with anomaly prediction, first-principles justification, and correction method. (Units: HOTS Analytical Reasoning)

💡 Examiner Directive: HOTS questions in ICSE evaluate depth of conceptual understanding. Avoid superficial guessing; reason backward from core laws.

🔑 Mandatory ICSE Examiner Technical Keywords Required in Solutions

Required for Step-Marking Credit

CISCE evaluators check for the explicit usage of mandatory technical terminology when scoring reasoning questions and step derivations. The table below outlines each key term, its technical description, the examiner marking directive, and the exact model answer phrasing expected in ICSE board examination solutions.

Mandatory Keyword #1 Core Definition Chapter Concept: Active vs Passive Immunity & Vaccination

1 Mark (Structural Location / Physiological Function)

"Active immunity body produces antibodies"

📘 Technical Definition & Detailed Description:

In ICSE Class 9 Biology (Hygiene, Health & Diseases), "Active immunity body produces antibodies" is an indispensable physiological term, anatomical structure, or biological process defined in the prescribed ICSE syllabus.

⚠️ CISCE Examiner Directive & Marking Rubric:

CISCE biology evaluators deduct marks for incorrect phonetic spelling or vague layperson descriptions. Candidates must use exact biological terminology: "Active immunity body produces antibodies".

📝 Model Answer Application (Exact Phrasing for Board Solutions):

"The physiological role of Active vs Passive Immunity & Vaccination is characterized by "Active immunity body produces antibodies", ensuring proper structural and functional regulation."

Mandatory Keyword #2 Core Definition Chapter Concept: Active vs Passive Immunity & Vaccination

1 Mark (Structural Location / Physiological Function)

"Memory cells long-lasting"

📘 Technical Definition & Detailed Description:

In ICSE Class 9 Biology (Hygiene, Health & Diseases), "Memory cells long-lasting" is an indispensable physiological term, anatomical structure, or biological process defined in the prescribed ICSE syllabus.

⚠️ CISCE Examiner Directive & Marking Rubric:

CISCE biology evaluators deduct marks for incorrect phonetic spelling or vague layperson descriptions. Candidates must use exact biological terminology: "Memory cells long-lasting".

📝 Model Answer Application (Exact Phrasing for Board Solutions):

"The physiological role of Active vs Passive Immunity & Vaccination is characterized by "Memory cells long-lasting", ensuring proper structural and functional regulation."

Mandatory Keyword #3 Core Definition Chapter Concept: Active vs Passive Immunity & Vaccination

1 Mark (Structural Location / Physiological Function)

"Passive immunity ready-made antibodies"

📘 Technical Definition & Detailed Description:

In ICSE Class 9 Biology (Hygiene, Health & Diseases), "Passive immunity ready-made antibodies" is an indispensable physiological term, anatomical structure, or biological process defined in the prescribed ICSE syllabus.

⚠️ CISCE Examiner Directive & Marking Rubric:

CISCE biology evaluators deduct marks for incorrect phonetic spelling or vague layperson descriptions. Candidates must use exact biological terminology: "Passive immunity ready-made antibodies".

📝 Model Answer Application (Exact Phrasing for Board Solutions):

"The physiological role of Active vs Passive Immunity & Vaccination is characterized by "Passive immunity ready-made antibodies", ensuring proper structural and functional regulation."

Mandatory Keyword #4 Core Definition Chapter Concept: Active vs Passive Immunity & Vaccination

1 Mark (Structural Location / Physiological Function)

"BCG for tuberculosis"

📘 Technical Definition & Detailed Description:

In ICSE Class 9 Biology (Hygiene, Health & Diseases), "BCG for tuberculosis" is an indispensable physiological term, anatomical structure, or biological process defined in the prescribed ICSE syllabus.

⚠️ CISCE Examiner Directive & Marking Rubric:

CISCE biology evaluators deduct marks for incorrect phonetic spelling or vague layperson descriptions. Candidates must use exact biological terminology: "BCG for tuberculosis".

📝 Model Answer Application (Exact Phrasing for Board Solutions):

"The physiological role of Active vs Passive Immunity & Vaccination is characterized by "BCG for tuberculosis", ensuring proper structural and functional regulation."

⚖️ CISCE Evaluation Directives for Biology

Step-Mark Allocation: Every sub-step, formula statement, and intermediate substitution carries independent marks. Writing final answers without formula yields zero in Section B numericals.

Mandatory SI Units: In ICSE Science and Mathematics, omitting SI units or writing incorrect unit exponents causes automatic 1/2 mark deduction per problem.

Examiner Technical Vocabulary: CISCE evaluators look for exact prescribed terms in definitions and reasoning questions. General paraphrasing often loses full credit.

📚 Other Class 9 Biology Solved Exercises

Solve Exercises Interactively in the App

Bookmark questions, get real-time AI Mentor hints for tough steps, and test your exam readiness with live timed quizzes.

⚡ Practice in Interactive ICSE Hub