Moss. Moss is mostly used for soil conditioners.
Answer:A checkpoint is a stage in the eukaryotic cell cycle at which the cell examines internal and external cues and "decides" whether or not to move forward with division.
Explanation: Easy Peasy
Answer:
Matter in an ecosystem:
- must be continuously replenished
- is recycled and reused
- is returned to the earth by decomposers
Virus are made with ADN or RNA only, which both of them has the information of replication. Once that the virus is in a cell, this ADN or RNA will be deposit inside the cell at the replication system that is going to make the virus reproduce unlimited times until the membranes of the cell break down. And they are useful because you can use them as a carrier or vector for treat diseases or for transgenics, bioterrorism, and so on.