What Is Living

8 MCQs9-step worked example
Source: NCERT Diversity in Living WorldOfficial key: NTA-verifiedLast updated: 26 Sep 2026

What Is Living, explained for NEET

What is Living?

The opening page of NCERT Class 11 Biology Chapter 1 poses a deceptively simple question: what makes something alive? This is where NEET catches aspirants — not with hard calculations, but with the assumption that a "simple" concept doesn't need precision.

The defining properties of life. Living organisms share a set of characteristics: growth, reproduction, metabolism, cellular organisation, consciousness (awareness of surroundings), and the ability to respond to stimuli. NCERT (Class 11 Biology (pre-2023 edition), Chapter 1, pages 3–5; NCERT removed this section from the current book in 2023, and the NEET (UG) 2026 syllabus still lists "What is living?") stresses that no single characteristic is sufficient on its own to define life.

The growth trap. Non-living things can grow too — crystals in a supersaturated solution increase in size by accumulation. But living growth is intrinsic: it happens by cell division from within. Mountains "grow" by tectonic uplift; that is not biological growth. NEET distractors exploit this overlap.

Reproduction is not a universal criterion. Mules, sterile worker bees, and infertile humans are alive but do not reproduce. If a question defines "living" solely by reproduction, it is a trap option. NCERT explicitly notes that reproduction cannot be an all-inclusive defining property.

Metabolism as the defining property. NCERT settles on metabolism — the sum of all chemical reactions occurring in the body — as the closest to a definitive characteristic. In isolation, no single metabolic reaction is "living," but the self-organised, self-regulating network inside a cellular system is unique to life. An isolated enzyme in a test tube catalyses a reaction (metabolism in vitro), but that does not make the test tube alive.

Consciousness. Even plants and lower organisms respond to external stimuli. Human beings are aware of themselves — self-consciousness — which NCERT flags as a distinguishing feature at the highest level.

Watch-out for NEET: questions frequently present a list of properties and ask which one is NOT a defining characteristic, or which one applies to non-living things as well. Growth and reproduction are the two standard trap answers.

Can you answer these What Is Living MCQs?

Select an option to see the explanation. Wrong answers show why your choice was tempting — and name the exact trap it exploits.

MCQ 1Easy RecallPractice

Which one of the following is considered the most defining characteristic of living organisms according to NCERT?

Show answer and why every option is right or wrong

Answer: B. NCERT Class 11 Biology (pre-2023 edition), Chapter 1, page 5 identifies metabolism — the sum total of all chemical reactions in the body — as the defining property of life, since growth and reproduction have exceptions.

Why A is wrong: A is wrong because reproduction cannot define life universally — mules and sterile worker bees are alive but do not reproduce. NCERT explicitly excludes it as an all-inclusive criterion.

Why C is wrong: C is wrong because non-living things also grow (e.g., mountains by tectonic activity, crystals by accretion). Growth alone does not distinguish living from non-living.

Why D is wrong: D is wrong because movement is not listed as a defining characteristic of life. Many organisms (e.g., rooted plants, fungi) do not show locomotion, yet are alive.

Report an error · Every fix is public: corrections log

MCQ 2Easy RecallPractice

Which of the following organisms demonstrates that reproduction is NOT a universal defining property of life?

Show answer and why every option is right or wrong

Answer: A. A mule is a sterile hybrid (horse × donkey) that cannot reproduce, yet is undeniably alive. NCERT uses such examples to argue that reproduction cannot be the sole criterion for life (NCERT Class 11 Biology (pre-2023 edition), Chapter 1, page 4).

Why B is wrong: B is wrong because Amoeba reproduces by binary fission — it does not serve as a counterexample to reproduction as a life criterion.

Why C is wrong: C is wrong because Hydra reproduces both sexually and asexually (budding), so it supports rather than contradicts reproduction as a life property.

Why D is wrong: D is wrong because yeast reproduces by budding and does not illustrate any failure of reproduction as a defining criterion.

Report an error · Every fix is public: corrections log

MCQ 3Easy RecallPractice

Growth in living organisms is fundamentally different from growth in non-living objects because living growth is:

Show answer and why every option is right or wrong

Answer: D. Living organisms grow from within by cell division (intrinsic growth), whereas non-living objects like crystals grow by addition of material from outside. NCERT Class 11 Biology (pre-2023 edition), Chapter 1, page 4 draws this distinction clearly.

Why A is wrong: A is wrong because 'accumulation from outside' describes non-living growth (e.g., crystal growth in a supersaturated solution). Living growth is intrinsic, not by external deposition.

Why B is wrong: B is wrong because biological growth involves both cell division and cell enlargement, and it is generally irreversible at the organism level (organs do not shrink back to embryonic size). 'Reversible' is incorrect.

Why C is wrong: C is wrong because living growth is intrinsic (from within), not extrinsic. Absorption of water contributes to turgor but is not the defining mechanism of biological growth.

Report an error · Every fix is public: corrections log

MCQ 4Direct ApplicationPractice

An isolated enzyme catalyses a reaction in a test tube. This demonstrates:

Show answer and why every option is right or wrong

Answer: C. NCERT (Class 11 Biology (pre-2023 edition), Chapter 1, page 5) explicitly notes that isolated metabolic reactions in vitro are not equivalent to life. Metabolism defines life only within the context of a self-organised cellular system.

Why A is wrong: A is wrong because a chemical reaction in a test tube does not make the system alive. NCERT distinguishes between isolated metabolic reactions and the integrated metabolism of a living cell.

Why B is wrong: B is wrong because enzymes absolutely can and do function outside living cells (in vitro biochemistry relies on this). The statement is factually incorrect.

Why D is wrong: D is wrong because isolated reactions do not constitute life. Life requires the full, coordinated metabolic network within cellular organisation — not a single catalytic event.

Report an error · Every fix is public: corrections log

MCQ 5Direct ApplicationPractice

A student argues that a virus is living because it can reproduce inside a host cell. Which property of life does the virus lack when outside a host?

Show answer and why every option is right or wrong

Answer: D. Outside a host cell, viruses have no metabolic activity — they cannot carry out any chemical reactions on their own. Since NCERT identifies metabolism as the defining property of life, the absence of independent metabolism is the critical distinction (NCERT Class 11 Biology (pre-2023 edition), Chapter 1, page 5).

Why A is wrong: A is wrong because consciousness (response to stimuli at an awareness level) is a higher-order property. The more fundamental deficit in viruses outside a host is the complete absence of metabolism — no chemical reactions occur at all.

Why B is wrong: B is wrong because viruses have a defined structural organisation (capsid, nucleic acid core, and sometimes an envelope). Structure is present; independent metabolic activity is not.

Why C is wrong: C is wrong because viruses do possess hereditary material (DNA or RNA) and can transmit genetic information. Heredity is not what they lack.

Report an error · Every fix is public: corrections log

MCQ 6Direct ApplicationPractice

A seed kept in dry storage for years shows no apparent metabolic activity. When placed in moist soil, it germinates. This example illustrates that:

Show answer and why every option is right or wrong

Answer: C. A dormant seed retains the cellular machinery for metabolism; conditions are simply unfavourable. Once conditions change, metabolism resumes and germination occurs. This supports NCERT's position that metabolism (including the potential for it in viable cells) defines life (NCERT Class 11 Biology (pre-2023 edition), Chapter 1, page 5).

Why A is wrong: A is wrong because a dormant seed is not dead — its cells are viable and retain the potential for metabolic activity. Dormancy is a reversible state, not death.

Why B is wrong: B is wrong because the seed example demonstrates metabolism resuming under favourable conditions, not reproduction. NCERT explicitly argues against reproduction as the defining criterion.

Why D is wrong: D is wrong because germination involves cell division and growth of existing living cells, not cell death and replacement. The mechanism described is factually incorrect.

Report an error · Every fix is public: corrections log

MCQ 7Concept TrapPractice

Which of the following is a property shared by BOTH living and non-living things?

Show answer and why every option is right or wrong

Answer: A. Both living and non-living things can grow — crystals grow in supersaturated solutions, and mountains, boulders and sand mounds grow by accumulation of material on the surface. NCERT (Class 11 Biology (pre-2023 edition), Chapter 1, page 4) uses this overlap to argue that growth alone cannot define life.

Why B is wrong: B is wrong because cellular organisation is exclusive to living organisms. Non-living objects do not have cells.

Why C is wrong: C is wrong because the self-organised network of chemical reactions that constitutes metabolism is unique to living systems. Isolated chemical reactions in non-living systems are not metabolism in the biological sense.

Why D is wrong: D is wrong because consciousness — awareness and self-awareness — is a property of living organisms, not of non-living matter. Even stimulus response at the basic chemical level in non-living systems is not consciousness.

Report an error · Every fix is public: corrections log

MCQ 8Concept TrapPractice

Self-consciousness is described as a distinguishing feature of humans. In lower organisms, the equivalent characteristic is best described as:

Show answer and why every option is right or wrong

Answer: B. NCERT (Class 11 Biology (pre-2023 edition), Chapter 1, page 5) notes that all living organisms respond to external stimuli — this is the basic form of consciousness/awareness. In humans this extends to self-consciousness. The equivalent in lower organisms is irritability (sensing and responding to the environment).

Why A is wrong: A is wrong because metabolism is the sum of chemical reactions, not awareness. While metabolism is the defining property of life, it is not the equivalent of consciousness in lower organisms.

Why C is wrong: C is wrong because reproduction is a separate life property dealing with producing offspring. It is unrelated to awareness or response to stimuli.

Why D is wrong: D is wrong because homeostasis refers to maintaining a stable internal environment. While linked to metabolism and responses, it is not the term used for the basic consciousness/awareness equivalent in lower organisms.

Report an error · Every fix is public: corrections log

Free NEET study resources

Get a structured 30-day study plan and a complete formula booklet — delivered to your inbox instantly.

How do you solve a What Is Living question? A worked example

  1. 1

    Given

    A question presents four statements about characteristics of living organisms:
    (i) Growth is always by cell division.
    (ii) Reproduction is a defining property of all living organisms.
    (iii) Metabolism in vitro means the test tube is alive.
    (iv) No single characteristic can define life; metabolism is the closest.

    The question asks: how many of the above statements are correct?

  2. 2

    Required

    Identify the number of correct statements.

  3. 3

    Concept

    NCERT's framework for "What is Living" (NCERT Class 11 Biology (pre-2023 edition), Chapter 1, pages 3–5): growth in living things is intrinsic (cell division), but non-living things also grow; reproduction has exceptions (mules, sterile organisms); isolated metabolic reactions do not confer "life"; no single criterion suffices but metabolism within cellular organisation is the closest.

  4. 4

    Formula

    No mathematical formula. This is concept-based evaluation.

  5. 5

    Substitution (statement-by-statement)

    • Statement (i): "Growth is always by cell division." — In living organisms, growth is intrinsic and involves cell division. However, the word "always" is too strong — even in living organisms, cell enlargement contributes. More importantly, non-living things also grow (without cell division). The statement as phrased about living growth by cell division is broadly correct for biological growth, but the absoluteness is debatable. For NEET purposes: essentially correct for living organisms.• Statement (ii): "Reproduction is a defining property of ALL living organisms." — FALSE. Mules, sterile worker bees, and infertile humans are alive but do not reproduce. NCERT explicitly flags this.• Statement (iii): "Metabolism in vitro means the test tube is alive." — FALSE. NCERT distinguishes isolated enzymatic reactions from the integrated metabolic network of a living cell.• Statement (iv): "No single characteristic can define life; metabolism is the closest." — TRUE. This is NCERT's stated conclusion.

  6. 6

    Calculation

    Correct statements: (i) is broadly correct, (iv) is correct = 2 correct statements.
    Incorrect statements: (ii) and (iii) = 2 incorrect statements.

  7. 7

    Final answer

    Two statements — (i) and (iv) — are correct.

  8. 8

    Common trap

    The most frequent trap is accepting statement (ii) because reproduction intuitively feels like a fundamental life property. NEET exploits this by listing mules or worker bees as exceptions — aspirants who don't recall the NCERT caveat lose marks.

  9. 9

    Similar NEET-style question

    "How many of the following can be used as the sole criterion to define living organisms?
    (a) Growth (b) Reproduction (c) Metabolism (d) Response to stimuli
    Options: A. One B. Two C. Three D. Four"
    (Answer: A — only metabolism within a cellular system comes closest, and even that with caveats. NCERT says no single property suffices, but metabolism is the nearest.)

    ---

What to remember before solving What Is Living questions

Definition

What is living?

In the NEET syllabus; removed from current NCERT.

Metabolism is a defining feature of all living organisms without exception; isolated metabolic reactions in vitro (in a test tube) are neither living nor non-living. Cellular organisation of the body is the defining feature of life forms. Consciousness, the ability to sense the surroundings and respond to physical, chemical or biological stimuli, is also a defining property. Living organisms are therefore self-replicating, evolving and self-regulating interactive systems capable of responding to external stimuli.

-- NCERT Class 11 Biology (pre-2023 edition), Chapter 1, p. 5
Key Fact

Growth and reproduction are not defining properties

In the NEET syllabus; removed from current NCERT.

Growth cannot be taken as a defining property of living organisms: non-living objects also grow if increase in mass is the criterion (mountains, boulders and sand mounds grow by accumulation of material on the surface), whereas in living organisms growth is from inside. Reproduction cannot be an all-inclusive defining characteristic either: many organisms do not reproduce (mules, sterile worker bees, infertile human couples).

-- NCERT Class 11 Biology (pre-2023 edition), Chapter 1, p. 4

More in Diversity in Living World: 16 exam traps and mistakes · 1 question pattern from its other lessons.

What Is Living questions from past NEET papers

No question in our NEET 2020–2025 set targets this topic directly.

All 59 past-paper questions from Diversity in Living World →

Sources

Page numbers are the ones printed in the current NCERT textbook (2023 rationalised edition), unless marked pre-2023. The books are free at ncert.nic.in.

Report an error · Every fix is public: corrections log

Test yourself on this topic with real past-paper questions:

Practice this topic →