The use is to guide and fix a replacement valve over the top of the old one.
TAVI is different from open heart surgery in that it uses a less invasive approach to treat a diseased aortic valve.
The organism that grows on the body of another organism and derives nutrients from it is known as a parasite. The organism that obtains nutrients from the dead or decaying organic matter is called saprotroph.
Eons: Hadean, Archean, Proterozoic
Okay. The destruction of tundra vegetation will not really freeze the soil or deepen the active zone much. Therefore, A and C are eliminated. The destruction of the vegetation can actually melt permafrost, which contributes to global warming. The answer is D.
