Valves ensure blood flows toward your heart. Vein valves work to bring the blood that flowed down via arteries back up to your heart.
A. behavioral isolation is when the plant or animal acts a particular way to attract their counterparts, like mating rituals.
geographic isolation is the natural barrier preventing similar species from interacting. for example, Galapagos Islands are the only home of flightless cormorants because the islands are so far from any other land for them to invade.
Temporal isolation is when two of the same or similar species cannot reproduce as a result of mismatched sexual maturity.
B. the isolation of two frog species by mating call is behavioral isolation.
<span>Although both macro algae and mangrove trees are multicellular and share many of the same structural features, macro algae are not true plants. Also, mangrove trees and marsh plants typically live in brackish water rather than salt water and are not completely submerged, as opposed to macro algae.</span>