It depends on what criteria are being used to define the period and anyway the definition is usually somewhat arbitrary.
For example, the beginning of the Baroque era in art is said to date from around 1600 and the Council of Trent. Art historians have been able to identify significant patterns in art and architecture. They have been able to suggest comparisons with music. However, they have been less successful in the case of writing.
Other eras are much easier to identify though. The Communist era in eastern Europe would be one example. Although it took some time for the Bolsheviks to establish complete sovereignty the results were obvious. At the end of this era again, although it took time for the régime to crumble the differences between what held before and after it existed were obvious.
he determines the cause of the crime
Volume.
Common Era or Current Era, abbreviated CE, is a calendar era that is often used as an alternative naming of the Anno Domini era ("in the year of the Lord"), abbreviated AD. The system uses BCE as an abbreviation for "before the Common (or Current) Era" and CE as an abbreviation for "Common Era". As of 2016, it started 2016 years ago.
The dinosaurs lived in the Mesozoic Era, which includes the Triassic, Jurassic, and Cretaceous periods. The first dinosaurs appeared in the late Triassic and went extinct at the end of the Cretaceous.
The Paleozoic era was from 540 million years ago to about 245 million years ago. After that came the Mesozoic era, and that lasted from the end of the Paleozoic to 65 million years ago, when the earth entered the Cenozoic era.
It was when Emperor Colonial ruled over the great city of Atlantis.
the answer is sex chromosomes
what determines a regions environment
Two points determines a line
The gene sequence determines the codon, which in turn determines the aminoacid, which in turn determines the tridimensional shape on the protein, which in turn determines the shape of the active site, which in turn determines what it'll be catalysing.
the number of protons determines the atom.
The temperature determines the color of the star!:)
Usually, its mass determines its weight.
Melanin determines your hair color.
A pitcher stat is a statistical number that determines how a pitcher has performed during his career. For instance, "H" tells you how many batters have gotten hits off of him. G is how many games he's participated in. ERA is a pitcher's earned run average. etc
The type of climate in a given area determines which plant will grow there.
Frequency determines this.