Testosterone<span> begins the development of secondary sexual characteristics.</span>
Some of the factors are:
<span>-Moderate climate.
-central geography,
-ease of transportation,
-highways,
-railroads,
-location near a large body of water
</span>Large cities tend to develop far from cities that had either too hot or too cold temperature. It also must be easily accessible by other regions and provide the people with necessary resources that help them sustain their living (such as water, food crops, woods, etc)
Anaphase I begins when the two chromosomes of each bivalent (tetrad) separate and start moving toward opposite poles of the cell as a result of the action of the spindle. Notice that in anaphase I the sister chromatids remain attached at their centromeres and move together toward the poles.
