The adaptations of organisms in a specific ecosystem are clues of evolution. for example, a giraffe has a long neck to reach leaves of high trees, birds migrate when cold weather comes etc
Has no meaning not a word
Flatworm get most of their oxygen through diffusion.
Sources of heat from inside earth is radioactive decay and residual heat.
The rough ER is involved with protein synthesis. It helps to produce proteins and help them fold properly.
