Science (086) — AI-generated practice question

Autotrophic Nutrition (Plants):
Autotrophs like green plants take in simple inorganic raw materials — carbon dioxide and water — from the environment. Using sunlight and chlorophyll, they convert these into carbohydrates through photosynthesis. This stores chemical energy in organic compounds like glucose and starch.

Heterotrophic Nutrition (Animals):
Heterotrophs cannot synthesise their own food. They consume complex organic material prepared by autotrophs. In humans, food is broken down by enzymes along the alimentary canal and absorbed in the small intestine, ultimately yielding glucose.

Common Final Process — Respiration:
Despite their different starting points, both autotrophs and heterotrophs arrive at glucose as the key organic compound. This glucose is then broken down during respiration (aerobic or anaerobic) in the mitochondria, releasing energy stored as ATP. ATP is the universal energy currency used for all cellular reactions in both types of organisms.

Thus, heterotrophs depend directly or indirectly on autotrophs, yet both share the same final mechanism of ATP generation through respiration.

Source: Chapter 5, Sections 5.2 and 5.2.1

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• The examiner wants: (1) clear definition/description of autotrophic nutrition with raw materials + energy source, (2) clear description of heterotrophic nutrition, (3) the link — both produce/obtain glucose → respiration → ATP.
• Key phrase from the textbook to include: "During respiration, organic compounds such as glucose are broken down to provide energy in the form of ATP."
• Don't just define the two modes — the question specifically asks you to connect them to the common ATP-generating process (respiration). That connecting paragraph is worth the most marks.
• Avoid writing more than ~120 words; the examiner rewards precision over length.