Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

[Q]: Question: What component of cells is present in plant and bacterial cells but not animal cells? Answer: cell wall
[A]: Animal Cell. The shape of an animal cell is not constrained by a rigid cell wall. A bacterial cell is shown above for comparison.

[Q]: Question: Wings of bats and birds serve the same function. which body part should you study to understand ancestral differences? Answer: bones inside wings
[A]: Wings of bats and birds serve the same function. Look closely at the bones inside the wings. The differences show they developed from different ancestors.

[Q]: Question: When gas particles collide, what kinds of collisions are these considered? Answer: elastic
[A]:
Collisions of gas particles are elastic, so no energy is lost.