Answer:
Ferns produce glucose that can be broken down by cellular respiration, while flatworms and people digest foods containing glucose for use in cellular respiration.
Step-by-step explanation:
Ferns, humans & flatworms all require cellular respiration to live. This energy-productive process occurs in the cell cytoplasm and mitochondria. However, for cellular respiration to occur, it has to work on an energy-rich substrate. In cells, this substrate is usually glucose. Ferns are autotrophs hence can make glucose by photosynthesis because they have chlorophyll molecules. However, flatworm and humans are heterotrophs meaning they have to consume other organic compounds to get this glucose.