In terms of function, bird wings are used to flap transversely, whereas butterfly wings are used to flap laterally. In terms of structure, bird wings are filled with hollow bones for easier flight, whereas butterfly wings are structured by scales and tiny hairs.
Instead of burning coal to power our country we could use solar panels. As long as we have the sun we will have "free" energy.
Instead of continuing to mine for metals, we could recycle metals and then less greenhouse gases would be released into Earth's atmosphere.
The chlorophyll stops being produced because it is to cold
It is called a gene, so the answer is b. gene