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Multiple Choice
Plants are photoautotrophs. What does this mean?
A
They can survive without any source of energy.
B
They rely on chemical energy from inorganic molecules without using light.
C
They obtain energy by consuming other organisms.
D
They use light energy to produce organic molecules from inorganic substances.
Verified step by step guidance
1
Understand the term 'photoautotroph': Break it down into 'photo-' meaning light and 'autotroph' meaning an organism that produces its own food. Photoautotrophs use light energy to synthesize organic molecules.
Clarify the process of photosynthesis: Photoautotrophs, such as plants, use light energy to convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂). This process occurs in chloroplasts and involves pigments like chlorophyll.
Compare photoautotrophs to other types of organisms: Unlike heterotrophs, which obtain energy by consuming other organisms, photoautotrophs produce their own food using light energy. They do not rely on consuming external organic matter.
Eliminate incorrect options: Plants cannot survive without energy, so the first option is incorrect. They do not rely solely on chemical energy from inorganic molecules without light, so the second option is incorrect. They do not obtain energy by consuming other organisms, so the third option is incorrect.
Confirm the correct answer: Plants are photoautotrophs because they use light energy to produce organic molecules (like glucose) from inorganic substances (like CO₂ and H₂O). This aligns with the correct answer provided in the problem.