For diffusion to occur, which condition must be met? A concentration gradient must exist.
A hypotonic external environment must exist.
A hypertonic external environment must exist.
Dynamic equilibrium must exist.

Which term best describes a community in which people work mostly in factories? a.agricultural. b.hunting and gathering. c.domesticated. industrial.

4the indian leaf butterfly has traits that allow it to resemble a leaf. the bright colors of the monarch butterfly indicate that the butterfly tastes bad and can be poisonous. how does the appearance of these butterflies them to survive? f the indian leaf butterfly is able to avoid predators while the monarch butterfly warns predators away. g. the indian leaf butterfly frightens predators away while the monarch butterfly poisons predators before they can eat it. h both butterflies rely on camouflage to avoid predation. j both butterflies cooperate with one another to avoid predation.

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this