Creationists often point to the complexity of cellular structures and functions as evidence for special-creation/intelligent-design, but they never point to other complex, higher-order biological systems in the same way.
Take for example an ecosystem, which is a community of organisms interacting with each other and their physical environment. Think deserts, think oceans, think your local flora and fauna. Ecosystems are every bit as complex as cells: they’re composed of different species; together they unwittingly carry out functions that are useful to us like oxygen creation and soil maintenance; and interactions that connect the different species to their environment, i.e., photosynthesis, symbiosis, competition, predation, are necessary to maintain the overall ecosystem function. Ecosystems can be sensitive and slow to adapt to massive change; altering them, for example by removing an apex predator, can have unpredictable and negative consequences. Think more jellyfish, larger algal blooms, less pristine and useful ecosystem functions like buffering soil pH and CO2 levels.
But you don’t see creationists clamoring to treat ecosystems as marvels of creation like they do cells. If they did, there’d be less outcry over stem cells and more outcry over pollution, overfishing, and habitat destruction. As always, the big picture is important. Maybe we should require students take Ecology 101 instead of just Cell Biology 101.