​Class 11 Biology MCQs: What is Living? | NCERT Chapter 1 Solutions

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Understanding the fundamental characteristics that define life: Growth, Metabolism, and Consciousness. 

  (NEET – The Living World):

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🌱 What is Living? – Simple Notes

🔹 1. Growth

• Living organisms grow from inside (internal growth).
• Growth in plants → continues throughout life.
• Growth in animals → stops after a certain age.
• Non-living things may increase in size, but:
  • It is external (not true growth).

👉 Example:

• Plant → keeps growing 🌿
• Human → stops growing after adulthood

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🔹 2. Reproduction

• Ability to produce new individuals.
• Important feature of living organisms.

👉 But:

• Some living organisms do not reproduce:
  • Mules
  • Worker bees
  • Infertile humans

✔️ So, reproduction is not a defining feature of life.

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🔹 3. Metabolism

• All chemical reactions inside the body = Metabolism
• Includes:
  • Anabolism (building)
  • Catabolism (breaking)

✔️ This is a defining feature of life
✔️ Happens only in living cells

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🔹 4. Cellular Organization

• All living organisms are made of cells.
• Cell = basic unit of life

👉 Types:

• Unicellular → Amoeba
• Multicellular → Humans

✔️ This is a defining property of living organisms

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🔹 5. Consciousness (Response to Stimuli)

• Ability to sense and respond to environment.

👉 Stimuli examples:

• Light ☀️
• Heat 🔥
• Chemicals

👉 Example:

• Touch plant closes when touched 🌿
• Humans feel pain

✔️ This is the most important defining feature of life

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🔹 6. Diversity in Living World

• Huge variety of organisms exist.
• To study them easily → Scientific naming (Nomenclature)

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🧬 Scientific Naming (Nomenclature)

🔹 Rules:

• Each organism has one unique name
• Names are:
  • Universal (same worldwide)
  • In Latin
  • Written in italics (or underlined if handwritten)

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🔹 Binomial Nomenclature

• Given by Carolus Linnaeus

👉 Each name has 2 parts:

1. Genus (First word, capital letter)
2. Species (Second word, small letter)

👉 Example:

• Mangifera indica (Mango)

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🔹 Important Codes

• ICBN → Plants
• ICZN → Animals

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🔹 Important Points for Exams

✔️ Growth alone ≠ living
✔️ Reproduction alone ≠ living
✔️ Metabolism = defining feature
✔️ Cellular organization = defining feature
✔️ Consciousness = most important feature

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🧠 Quick Mind Map (Text)

Living Organisms
│
├── Growth
│ ├─ Plants → lifelong
│ └─ Animals → limited
│
├── Reproduction
│ └─ Not in all organisms
│
├── Metabolism ✅
│
├── Cellular Organization ✅
│
├── Consciousness ✅ (Most Important)
│
└── Scientific Naming
├─ Binomial system
├─ Genus + Species
└─ Latin names

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🔗 Internal Link 

• ​Next Lesson: Biological Classification: 5 Kingdom System MCQs
• ​Study Guide: How to Memorize NCERT Biology for NEET
• ​Related Topic: Cell: The Unit of Life – Detailed Notes
• ​Practice Paper: Biology Previous Year Question Papers

Biology: What is Living? (MCQs 1-10)

1. Which biologist has been called 'The Darwin of 20th century'?

• (a) Aristotle
• (b) Carolus Linnaeus
• (c) Ernst Mayr
• (d) R.H. Whittaker

Correct Answer: (c)

Ernst Mayr was a renowned evolutionary biologist who is widely referred to as the "Darwin of the 20th Century" for his contributions to the biological species concept.

2. In plants, growth occurs _________ whereas in animals, it occurs _________.

• (a) only upto a certain age, continuously
• (b) continuously, only upto a certain age
• (c) continuously, continuously
• (d) only upto a certain age, only upto a certain age

Correct Answer: (b)

Plants have meristematic tissues that allow for continuous growth throughout their lifespan. In contrast, animals grow only up to a specific age, though cell division continues to replace lost or damaged cells.

3. Which two of the following features are known as the twin characteristics of growth?

(i) Increase in mass
(ii) Increase in number of individuals
(iii) Cellular organisation
(iv) Cellular differentiation

• (a) (i) and (ii)
• (b) (i) and (iii)
• (c) (ii) and (iii)
• (d) (iii) and (iv)

Correct Answer: (a)

According to NCERT, the "twin characteristics of growth" are defined as the increase in body mass and the increase in the number of individuals/cells.

4. Which of the following groups consists of organisms which multiply by fragmentation?

• (a) Earthworm, Amoeba, fungi
• (b) Earthworm, fungi, bacteria
• (c) Fungi, filamentous algae, protonema of mosses
• (d) Amoeba, Hydra, bacteria

Correct Answer: (c)

Fungi, filamentous algae, and the protonema of mosses all easily multiply through fragmentation, where a piece of the organism breaks off and grows into a new individual.

5. Which of the following organisms do not reproduce?

• (a) Mules
• (b) Worker bees
• (c) Infertile human couples
• (d) All of these

Correct Answer: (d)

While these are living organisms, they are sterile. Mules, worker bees, and infertile human couples cannot produce offspring, which is why reproduction is not considered a "defining" property of life.

6. Why growth cannot be taken as a defining property of living organisms?

• (a) Some living organisms do not show growth at all.
• (b) In case of larvae, growth is not visible.
• (c) Dormant seeds do not grow.
• (d) Non-living objects also grow by increase in body mass.

Correct Answer: (d)

Non-living things like mountains or sand dunes "grow" by accumulation of material on their surface (extrinsic growth). Since growth is not exclusive to living beings, it isn't a defining property.

7. Which of the following statements regarding the response of living organisms to external stimuli is correct?

• (a) The external environmental stimuli can be physical, chemical or biological.
• (b) All organisms, from the prokaryotes to the most complex eukaryotes can sense and respond to environmental stimuli.
• (c) Consciousness and response to external stimuli are the defining properties of living organisms.
• (d) All of these

Correct Answer: (d)

All the statements are accurate. Consciousness (the ability to sense surroundings and respond) is a universal and defining characteristic of all living life forms.

8. Read the following statements and select the correct ones:

(i) Increase in mass and increase in number of individuals are twin characteristics of growth.
(ii) Metabolic reactions can be demonstrated outside the body in isolated cell-free systems.
(iii) 'Response to stimuli' is a defining property of living organisms.

• (a) (i) and (ii) only
• (b) (ii) and (iii) only
• (c) (i) and (iii) only
• (d) (i), (ii) and (iii)

Correct Answer: (d)

All three statements are correct biological facts based on the characteristics of living organisms and laboratory demonstrations of metabolism.

9. Match column I with column II and select the correct option:

Column I	Column II
A. Planaria	(i) Binary fission
B. Fungi	(ii) Asexual spores
C. Yeast	(iii) Budding
D. Amoeba	(iv) True regeneration
	(v) Fragmentation

Correct Answer: (c) A-(iv), B-(v), C-(iii), D-(i)

Planaria show true regeneration; Fungi commonly multiply via fragmentation; Yeast reproduces by budding; Amoeba reproduces via binary fission.

10. A living organism is unexceptionally differentiated from a non-living structure on the basis of:

• (a) locomotion
• (b) growth and movement
• (c) response to stimuli
• (d) none of these.

Correct Answer: (c)

"Unexceptionally" means without exception. While some living things don't grow (sterile) or move (plants), every single living organism responds to stimuli (consciousness).