If the poreis completely closed to the surface, the result is a whitehead. If the pore is wide open, oil becomes oxidized (that is, acted on by oxygen in the air), the oil changes from white to black, and the result is a blackhead. This is how the two types of comedones develop. Comedo is the Latin word for glutton.
The Amazon rainforest topical climate. Tropical climate refers to zones in a range of latitudes between 5/10 to 35. The temperatures remain high all over the year and shows an annual wide change in precipitations with wet and dry seasons: The dry season duration is proportional to the latitude to ultimatly become a mostly dry area.
Precipitation Figure 9.7 A Baobab tree, with its thick trunk and large edible fruit, Dakar, Senegal. (UN/DPI Photo #187250C by Evan Schneider) The Tropical Wet/Dry climate is the driest of the tropical wet climates.Like the monsoon climate, it has a distinct seasonality to its precipitation. However, its wet season is much shorter and receives far less precipitation than the monsoon climate.owever, the average annual temperature is similar to that of the other tropical wet climates. Mean monthly temperatures in the Tropical Wet/Dry climate range from 18 o C (64.4 o F) to above 25 o C (77 o F).