What unique features of veins move blood back to the heart?

Nteractions between organisms and their environment impact the organism’s overall population. oahu amakihi and kauai amakihi are two closely related species of hawaiian honeycreepers. they have a common ancestor, eat small insects and nectar, and like to nest in koa trees. however, one species is found on the island of oahu, and the other is found on the island of kauai. which concept shows the relationship between oahu amakihi and kauai amakihi?

Molecular models of two different substances are shown below. in the molecule on the left, the oxygen atom pulls on electrons more strongly than the hydrogen atoms. in the molecule on the right, the two oxygen atoms pull on the shared electrons with the same strength. water molecule, h, o oxygen molecule, oz when the two substances are put in the same container, they do not attract each other. why does this happen? a. they both contain oxygen. b. one is polar and one is nonpolar. c . they are both polar. d. they contain different elements.

Deer cave cannot support photosynthesis is as not enough sunlight is present. in spite of this, it still has a complex food chain. what is the energy foundation of this food chain?