Answer:Valves stop blood flowing backwards
Explanation: Valve are flags of tissue that control the direction of the blood in our heart.,it prevent the backwards flow of blood. valves regulate blood from flowing back into the atria.The right and left atrio-ventricular valves prevent blood from flowing backwards into atria. When the ventricle is full,the valve prevent backwards flow of blood.
In prokaryotic cells, there is only one point of origin, replication occurs in two opposing directions at the same time, and takes place in the cell cytoplasm. Eukaryotic cells on the other hand, have multiple points of origin, and use unidirectional replication within the nucleus of the cell.
In general, pseudoscience is based on "<span>static information that does not change" because this kind of fake science doesn't change when new evidence is brought into light. </span>
Answer:
The correct answer is option d. "Many species that moved into North America from South America outcompeted the endemic taxa and still exist today".
Explanation:
The Great American Biotic Interchange (GABI) was an historical period at which numerous species from South America migrated to North America, and numerous species from North America migrated to South America because of the formation of the Isthmus of Panama. During this event, many species that moved into North America from South America outcompeted the endemic taxa and still exist today. The species that successfully immigrated to South America and exist today were mostly small mammals, such as armadillos and opossums.
has tremendous biodiversity and high rates of endemic species: of more than 200,000 known species found on Madagascar, more than 80 percent exist nowhere else. Unique to the island are over 100 kinds of lemurs, over 300 species of frogs, and 33 species of tenrecs, miniature hedgehog-like animals. However, it is one of the most threatened ecosystems on the planet.