Regarding modes of nutrition, consider the following statements: 1. Autotrophs utilise complex organic substances as raw materials. 2. Heterotrophs require enzymes to break complex food into simpler forms. 3. Heterotrophs are directly or indirectly dependent on autotrophs for survival. Which of the statements given above are correct?

Correct Option The correct option is 2 and 3 only. Explanation Living organisms are classified based on their mode of nutrition into autotrophs and heterotrophs. This classification depends on the source of carbon and energy used by the organism to sustain life processes. Statement-wise Analysis - Statement 1 is Incorrect. Autotrophs (such as green plants and certain bacteria) do not utilize complex organic substances as raw materials. Instead, they utilize simple inorganic substances like carbon dioxide and water from the environment to synthesize complex organic substances (carbohydrates) in the presence of sunlight and chlorophyll. - Statement 2 is Correct. Heterotrophs utilize complex organic substances derived from other organisms. These complex substances cannot be used directly by the body for maintenance and growth; they must be broken down into simpler, soluble forms. This breakdown is achieved through the action of bio-catalysts known as enzymes. - Statement 3 is Correct. Heterotrophs lack the ability to synthesize their own food from inorganic raw materials. Consequently, they depend directly (herbivores) or indirectly (carnivores) on autotrophs for their energy and survival requirements. Key Takeaway Autotrophs synthesize food using simple inorganic raw materials (CO2, H2O), whereas heterotrophs consume complex organic matter and rely on enzymes to digest it into simpler forms.

NCERT Class 10 Science — Chapter 1: Life Processes

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Regarding modes of nutrition, consider the following statements:

Autotrophs utilise complex organic substances as raw materials.
Heterotrophs require enzymes to break complex food into simpler forms.
Heterotrophs are directly or indirectly dependent on autotrophs for survival.

Which of the statements given above are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A2 only
B1, 2 and 3
C1 and 2 only
D2 and 3 only

Did you get this right?

Solution

Correct Option

The correct option is 2 and 3 only.

Explanation

Living organisms are classified based on their mode of nutrition into autotrophs and heterotrophs. This classification depends on the source of carbon and energy used by the organism to sustain life processes.

Statement-wise Analysis

Statement 1 is Incorrect. Autotrophs (such as green plants and certain bacteria) do not utilize complex organic substances as raw materials. Instead, they utilize simple inorganic substances like carbon dioxide and water from the environment to synthesize complex organic substances (carbohydrates) in the presence of sunlight and chlorophyll.
Statement 2 is Correct. Heterotrophs utilize complex organic substances derived from other organisms. These complex substances cannot be used directly by the body for maintenance and growth; they must be broken down into simpler, soluble forms. This breakdown is achieved through the action of bio-catalysts known as enzymes.
Statement 3 is Correct. Heterotrophs lack the ability to synthesize their own food from inorganic raw materials. Consequently, they depend directly (herbivores) or indirectly (carnivores) on autotrophs for their energy and survival requirements.

Key Takeaway

Autotrophs synthesize food using simple inorganic raw materials (CO₂, H₂O), whereas heterotrophs consume complex organic matter and rely on enzymes to digest it into simpler forms.

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More from Chapter 1: Life Processes

Which enzyme, present in saliva and pancreatic juice, is primarily responsible for the breakdown of starch into simpler sugars?

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The accumulation of which compound in muscle cells leads to cramps during sudden physical activity or anaerobic respiration?

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Which hair-like structures lining the upper respiratory tract help in filtering air by trapping dust and particles?

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In the circulatory system of fishes, the heart is characteristically composed of how many chambers?

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With reference to maintenance functions in organisms, consider the following statements: 1. The transfer of energy source from outside to inside is referred to as respiration. 2. These processes require energy sourced from outside the body. 3. All organisms obtain energy directly from sunlight. Which of the statements given above is/are correct?

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Correct Option

The correct option is 2 and 3 only.

Explanation

Statement-wise Analysis

Statement 1 is Incorrect. Autotrophs (such as green plants and certain bacteria) do not utilize complex organic substances as raw materials. Instead, they utilize simple inorganic substances like carbon dioxide and water from the environment to synthesize complex organic substances (carbohydrates) in the presence of sunlight and chlorophyll.
Statement 2 is Correct. Heterotrophs utilize complex organic substances derived from other organisms. These complex substances cannot be used directly by the body for maintenance and growth; they must be broken down into simpler, soluble forms. This breakdown is achieved through the action of bio-catalysts known as enzymes.
Statement 3 is Correct. Heterotrophs lack the ability to synthesize their own food from inorganic raw materials. Consequently, they depend directly (herbivores) or indirectly (carnivores) on autotrophs for their energy and survival requirements.

Key Takeaway

Autotrophs synthesize food using simple inorganic raw materials (CO₂, H₂O), whereas heterotrophs consume complex organic matter and rely on enzymes to digest it into simpler forms.