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.
Tropical Moist (Group A) climates are found in a band about 15Â° to 25Â° N and S of the equator (Figure 17.8). Intense sunshine means that the tropics are warm year-round: each month has an average temperature of at least 18Â°C (64Â°F). Rainfall is abundantâat least 150 cm (59 inches) per year.he tropical monsoon climate resembles the tropical wet biome (Af) but has very low precipitation for one to two months each year. During these months, less than 6 cm (2.4 inches) of rain falls. Rainforests can grow here because the dry period is short, and the trees can be supported by moisture trapped in the soil.