Step-by-step ICSE solutions and marking scheme for Chemical Coordination in Plants: Plant Hormones from Selina Concise Biology (Class 10) - Chapter 7 and 5 generated practice problem sets.

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

📘 Open Chapter Notes (class10_biology_chemical_coordination_in_plants_plant_hormones.html) →

Biology Chapter 5 1 Textbook + 5 Generated Exercises 6 - 8 Marks in ICSE Board Exam

Chemical Coordination in Plants: Plant Hormones — Solved Textbook & 5 Practice Sets

Prescribed Reference Textbook: Selina Concise Biology (Class 10) - Chapter 7

Canonical Link: https://icse.smartindia.pro/class10_biology_solved_exercise_chemical_coordination_in_plants_plant_hormones.html

Prerendered HTML Page: class10_biology_solved_exercise_chemical_coordination_in_plants_plant_hormones.html

📘 Prescribed Textbook Solved Exercise (Selina Concise Biology (Class 10))

Primary Curriculum Benchmark

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

Textbook Exercise 5 - Review Questions Q.5 Selina Concise Biology (Class 10) - Chapter 7 - End-of-Chapter Review

3 Marks Allotted

With reference to Chemical Coordination in Plants: Plant Hormones: (i) Define the biological process of Auxin Action & Tropic Movements. (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 Auxin Action & Tropic Movements incorporating mandatory ICSE terminology: Auxin causes cell elongation and apical dominance, Auxin accumulates on shaded side, ABA is stress hormone inducing stomatal closure.

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 "Auxin Action & Tropic Movements" in the context of ICSE Class 10 Biology. State its primary characteristic or SI unit/standard symbol.

Step-by-Step Marking Breakdown

Step 1: Precise Technical Definition

Auxins promote cell elongation. In phototropism, auxins migrate towards the shaded side of shoot tip, causing shaded cells to grow faster and bending shoot towards light. In root, ...

1 Mark

Step 2: Mandatory Technical Criteria

Ensure the definition contains mandatory keywords: Auxin causes cell elongation and apical dominance, Auxin accumulates on shaded side, ABA is stress hormone inducing stomatal closure.

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 "Auxin Action & Tropic Movements". 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 Auxin Action & Tropic Movements.

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 Auxin Action & Tropic Movements (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 "Auxin Action & Tropic Movements" and "Auxin Action & Tropic Movements" 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: Auxin Action & Tropic Movements focuses on Auxin causes cell elongation and apical dominance, whereas Auxin Action & Tropic Movements emphasizes Auxin causes cell elongation and apical dominance.

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 "Chemical Coordination in Plants: Plant Hormones":
(i) State the fundamental law or rule governing "Auxin Action & Tropic Movements". [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 Auxin causes cell elongation and apical dominance with related quantities. The correct understanding requires strict application of Auxin Action & Tropic Movements.

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 "Chemical Coordination in Plants: Plant Hormones": An experiment is performed under non-ideal conditions involving "Auxin Action & Tropic Movements" and "Auxin Action & Tropic Movements".
(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: Auxin causes cell elongation and apical dominance, Auxin accumulates on shaded side, ABA is stress hormone inducing stomatal closure, Ethylene is gaseous hormone promoting fruit ripening.

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: Auxin Action & Tropic Movements

1 Mark (Structural Location / Physiological Function)

"Auxin causes cell elongation and apical dominance"

📘 Technical Definition & Detailed Description:

In ICSE Class 10 Biology (Chemical Coordination in Plants: Plant Hormones), "Auxin causes cell elongation and apical dominance" 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: "Auxin causes cell elongation and apical dominance".

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

"The physiological role of Auxin Action & Tropic Movements is characterized by "Auxin causes cell elongation and apical dominance", ensuring proper structural and functional regulation."

Mandatory Keyword #2 Core Definition Chapter Concept: Auxin Action & Tropic Movements

1 Mark (Structural Location / Physiological Function)

"Auxin accumulates on shaded side"

📘 Technical Definition & Detailed Description:

In ICSE Class 10 Biology (Chemical Coordination in Plants: Plant Hormones), "Auxin accumulates on shaded side" 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: "Auxin accumulates on shaded side".

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

"The physiological role of Auxin Action & Tropic Movements is characterized by "Auxin accumulates on shaded side", ensuring proper structural and functional regulation."

Mandatory Keyword #3 Core Definition Chapter Concept: Auxin Action & Tropic Movements

1 Mark (Structural Location / Physiological Function)

"ABA is stress hormone inducing stomatal closure"

📘 Technical Definition & Detailed Description:

In ICSE Class 10 Biology (Chemical Coordination in Plants: Plant Hormones), "ABA is stress hormone inducing stomatal closure" 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: "ABA is stress hormone inducing stomatal closure".

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

"The physiological role of Auxin Action & Tropic Movements is characterized by "ABA is stress hormone inducing stomatal closure", ensuring proper structural and functional regulation."

Mandatory Keyword #4 Core Definition Chapter Concept: Auxin Action & Tropic Movements

1 Mark (Structural Location / Physiological Function)

"Ethylene is gaseous hormone promoting fruit ripening"

📘 Technical Definition & Detailed Description:

In ICSE Class 10 Biology (Chemical Coordination in Plants: Plant Hormones), "Ethylene is gaseous hormone promoting fruit ripening" 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: "Ethylene is gaseous hormone promoting fruit ripening".

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

"The physiological role of Auxin Action & Tropic Movements is characterized by "Ethylene is gaseous hormone promoting fruit ripening", ensuring proper structural and functional regulation."

Mandatory Keyword #5 Core Definition Chapter Concept: Auxin Action & Tropic Movements

1 Mark (Structural Location / Physiological Function)

"Thigmonasty in Mimosa pudica (sleeping movement)"

📘 Technical Definition & Detailed Description:

In ICSE Class 10 Biology (Chemical Coordination in Plants: Plant Hormones), "Thigmonasty in Mimosa pudica (sleeping movement)" 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: "Thigmonasty in Mimosa pudica (sleeping movement)".

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

"The physiological role of Auxin Action & Tropic Movements is characterized by "Thigmonasty in Mimosa pudica (sleeping movement)", 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 10 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