Why does smoke comes from our mouth in winter?

The leopard frog and the pickerel frog are two closely related species. in areas where their ranges overlap, the frogs will remain separate species if they

Adistinctive characteristic of mammals that is not observed in other vertebrates is

Molecules like glucose and amino acids are not lipid soluble, so cannot cross the cell membrane by simple diffusion. instead, they are shuttled across by carrier proteins in the membrane from high to low concentration. does this process require energy from the cell? this is an example of what type of molecular movement?