Why do the red blood cells move to the bottem, while the plasma cells move to the top?

The first element on the periodic table of elements is carbon. a. true b. false

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

An observation that requires measurement is called quantitative observable or qualitative