One way that they are economically valuable is that it is mostly made up of the stuff that we have and need now like papers, tables, money, houses, etc. Wood is very very important in the human society and the place to get them is the forests.
A way that it is ecologically valuable is that the trees create habitats for the animals that live in the forests for protection from storms, other animals, etc. The trees in the forest can also be a source of food for some animals because those animal can feed on the leaves.
Answer: Pretty much every aspect of them
Explanation:
Stem cells have unique regenerative abilities which can be used for treating diseases and disabilities (from diabetes to MS). They can also be used to graph skin from burns etc. The stem cell science world seems to leave so many options open for discoveries and they have less negative side effects in comparison to the chemical treatments available or soon to become available. Stem cells can heal rather than pharma therapies covering the ailment and leading to other issues.
S phase is the DNA synthesis phase. During this portion of the cell cycle, the cell replicates its entire complement of DNA. It also forms the centrosome, which is the microtubule-organizing center that will eventually help the cell pull apart the DNA that will be divided between daughter cells.