Peristalsis<span> is a radically symmetrical </span><span> contraction and relaxation of muscles</span><span> that propagates in a wave</span><span> down a tube, in an anterograde direction.</span>
A. Hormones
secreted directly into the blood
Answer:
There are eight major terrestrial biomes: tropical wet forests, savannas, subtropical deserts, chaparral, temperate grasslands, temperate forests, boreal forests, and Arctic tundra. ... Other biomes, such as deserts and tundra, have low primary productivity due to extreme temperatures and a shortage of available water.
Explanation:
<span>The Answer is D. Maintaining Structure</span>