<span>
The populations become completely separated from one another</span>
Answer:
b. There is insufficient contrast in surface type (land vs. ocean) in the middle latitudes.
Explanation:
The sources of air masses can be produced or at very high latitudes because they can carry big amounts of air from the top of a mountain till the bottom by the differences of pressure and temperatures. This kind of air mass is called continental.
In the other hand, in a low latitude, the air coming from the sea, try to reach higher latitudes, again, by pressure and temperatures differences. These kind of air masses are called maritime.
Hope it was useful.
The tropical forests can roughly be divided into two major groups, tropical evergreen forests and tropical deciduous forests. The division is made in accordance to the characteristics of the trees.
The trees in the tropical evergreen forests are green throughout all of the year. The reason behind this is that they have constant temperature all year long, and constantly high amounts of rainfall all year long, so there is no need for them to shed their leaves.
The trees in the tropical deciduous forests, on the other hand, are shedding their leaves. This means that in one part of the year these trees have green leaves, while in the other part of the year they are shedding their leaves and the branches are stripped. The main reason behind this is that the rainfall occurs only seasonally, when pretty much all rainfall for the year falls in few months. After that, a very long period of drought and very high temperatures starts. In order to survive and not get damaged, the trees are shedding their leaves, thus they almost put them selves in an hibernating phase until the next rainy season.
