The geologic time scale is a system of chronological dating that relates geological strata to time, and is used by geologists, paleontologist, and other Earth scientists to describe the timing and relationships of events that have occurred during Earth's history. Hope I helped!
Yes it is.
Carbon dioxide goes through plants, which they turn into oxygen. Humans and animals take in the oxygen and breathe out carbon dioxide. Then it repeats.
The process by which cell types or cell populations attain distinct and different forms and functions is called differentiation.
This is the process that allows the stem cells to differentiate and form a cell type that will perform a specific function.
The process of differentiation is essential for the formation of the different organs in multicellular organisms.
An animal that is healthier will have a better chance of survival due to better strength, and also be better suited to winning a mate. Animals that are weak or sick are most likely to die off or be killed by a predator or natural reasons, if this animal survives, it will most likely not get a mate because the mate will not be attracted to the sickened animal, considering how most animals search for a healthy mate to reproduce with. (Usually there is some type of court ship dance or song of some sort, and it is usually the more healthy animal that is able to "perform" the best dance/song for the mate it is trying to win over) Hope that this helped!