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Chemical Basis of Life Grade 10 Science lesson 01 Quiz 03

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Free G.C.E. O/L Science MCQ quiz on Chemical Basis of Life with 10 questions in English medium. Answer each question, see the correct answer and explanation straight away, and get your score at the end. Use the study section below to review every question and answer.

සාමාන්‍ය පෙළ Science බහුවරණ ප්‍රශ්න නොමිලේ පුහුණු වන්න.

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Chemical Basis of Life Free Online Quiz: Practice MCQs & Exam Revision

Test your understanding of the foundational principles of biology and biochemistry with this free interactive quiz on the Chemical Basis of Life. Whether you are preparing for term tests, competitive school exams, or international board evaluations, this practice test is designed to reinforce core concepts and identify knowledge gaps.

Mastering the molecular building blocks of organisms is essential for excelling in general science and advanced biology. This quiz features exam-standard multiple-choice questions (MCQs) structured to evaluate both theoretical recall and practical application.

Key Topics Covered:
Major Biomolecules: Structure, classification, and biological roles of carbohydrates, proteins, lipids, and nucleic acids (DNA & RNA).

Biochemical Food Tests: Diagnostic identification tests, including Benedict’s test for reducing sugars, Iodine test for starch, Biuret test for proteins, and Sudan III/emulsion tests for lipids.

Water & Essential Minerals: Polarity, universal solvent properties, thermal buffering, and the physiological importance of macro and micro minerals.

Enzymes & Biological Regulators: Enzyme-substrate specificity, factors affecting reaction rates (pH, temperature), and essential vitamins.

Why Take This Practice Quiz?
Instant Feedback & Scoring: View your score immediately upon completion with detailed question-by-question breakdowns.

Exam-Aligned Questions: Crafted around commonly tested syllabus points to mirror realistic exam difficulty.

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Who Is This Quiz For?
High school science and biology students preparing for unit assessments and final exams.

Teachers and tutors seeking a ready-made digital assessment tool for classroom review.

Independent learners looking to build a rock-solid foundation in life sciences.

All questions & answers (10)

Study mode: read every question, then open the answer. Tap to show.

  1. Q1. Which of the following pairs groups water-soluble vitamins together?

    • A)Vitamins A and D
    • B)Vitamins B and C
    • C)Vitamins E and K
    • D)Vitamins A and K
    Show answer & explanation

    Answer: B) Vitamins B and C

    Vitamins B and C dissolve in water, whereas vitamins A, D, E, and K are fat-soluble.

  2. Q2. What is the end product formed when starchy foods undergo complete hydrolysis?

    • A)Fructose
    • B)Glucose
    • C)Sucrose
    • D)Cellulose
    Show answer & explanation

    Answer: B) Glucose

    Hydrolysis of all starchy foods breaks down the polysaccharide chains into glucose units.

  3. Q3. Which of the following is NOT a lipid compound?

    • A)Gingelly oil
    • B)Butter
    • C)Glycogen
    • D)Cholesterol
    Show answer & explanation

    Answer: C) Glycogen

    Glycogen is a polysaccharide (carbohydrate), whereas butter, oils, and cholesterol are lipids.

  4. Q4. Which element is always present in proteins along with Carbon, Hydrogen, and Oxygen, but is NOT a standard component of pure carbohydrates?

    • A)Phosphorus
    • B)Nitrogen
    • C)Calcium
    • D)Iron
    Show answer & explanation

    Answer: B) Nitrogen

    Nitrogen is a fundamental constituent of amino acids and proteins, setting them apart from standard carbohydrates and lipids.

  5. Q5. The conversion of sucrose into glucose can be achieved in a laboratory setting by heating with a dilute acid, but in living bodies, it is performed rapidly at low temperatures by:

    • A)Hormones
    • B)Enzymes
    • C)Nucleic acids
    • D)Mineral ions
    Show answer & explanation

    Answer: B) Enzymes

    Biological catalysts called enzymes accelerate biochemical reactions smoothly at body temperature without requiring harsh acids or excessive heat.

  6. Q6. What is the primary role of lipids in warm-blooded animals such as birds and mammals?

    • A)Genetic information transfer
    • B)Thermal insulation via a hypodermal fat layer
    • C)Catalyzing metabolic reactions
    • D)Immediate energy release in nerves
    Show answer & explanation

    Answer: B) Thermal insulation via a hypodermal fat layer

    A hypodermal fat layer acts as a thermal insulator to help maintain constant body temperature in endothermic animals.

  7. Q7. Which biological molecule serves as the primary and immediate energy source for the activities of living organisms?

    • A)Nucleic acids
    • B)Carbohydrates
    • C)Minerals
    • D)Vitamins
    Show answer & explanation

    Answer: B) Carbohydrates

    Carbohydrates, particularly through the oxidation of glucose, serve as the main energy source for cellular activities.

  8. Q8. What observation confirms the presence of water in food during the heating experiment (Activity 02)?

    • A)Blue anhydrous cobalt chloride turns pink
    • B)Solution turns purplish-blue
    • C)Red fat globules appear
    • D)Coal lines are left on white paper
    Show answer & explanation

    Answer: A) Blue anhydrous cobalt chloride turns pink

    Anhydrous cobalt chloride changes from blue to pink in the presence of water vapor condensed on the glass sheet.

  9. Q9. Which of the following hormones is correctly matched with its chemical category as a lipid derivative?

    • A)Insulin
    • B)Growth hormone
    • C)Testosterone
    • D)Thyroxine
    Show answer & explanation

    Answer: C) Testosterone

    Testosterone, oestrogen, and cortisol are steroid hormones synthesized from lipid compounds.

  10. Q10. What is the main structural function of cellulose in plants?

    • A)Storing energy in seeds
    • B)Building cell walls
    • C)Transporting phloem sap
    • D)Acting as a respiratory enzyme
    Show answer & explanation

    Answer: B) Building cell walls

    Cellulose forms the rigid structural framework of plant cell walls, providing mechanical support and dietary fiber.

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