Era is used to mark the boundaries of geological time scale by using radio carbon dating technique.
Explanation:
Geological time starts with Precambrian time.
Geologically, time is divided between the Precambrian era and present time into era.
The three eras are Paleozoic era, Triassic period and Cenozoic era.
Era is further divided into periods.
Scientists use radio carbon dating to study fossils and rock formation. With this study they were able to divide them in exact geological scale.
Geologic scale is the record of events in earth's history and evolution.
B! The strongest characteristics will survive when the weak ones won't
Answer:
This means that some cells are able to letter molecules pass through them and this makes it easier for the molecules to pass through.
The answer is iron. Research has shown an increase in serum iron concentreation in athletes and a concomitant decrease in magnesium ions. The increase in iron concentration is thought to be attributed to tissue injury from the strenuous physical activity. The decrease in magnesium is due to demand by the skeletal muscles.
