Richard was observing black swallowtail butterflies in the field. which one of these is an observation he made about a black swallowtail butterfly?

Which of the following is a difference between active transport and facilitated diffusion? view available hint(s)which of the following is a difference between active transport and facilitated diffusion? facilitated diffusion can move solutes against a concentration gradient, and active transport cannot.active transport involves transport proteins, and facilitated diffusion does not.facilitated diffusion involves transport proteins, and active transport does not.active transport requires the expenditure of cellular energy, and facilitated diffusion does not.

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from