The answer is; the melanin in darkly pigmented skin protects DNA from UV radiation, and UV radiation can cause skin cancer
In Africa, due to its equatorial latitude location, receives direct sunlight at more or less 90 degrees most of the year. These highly concentrated rays increase the UV radiation exposure that can cause damage to cell DNA. Selection pressure, therefore, favored individuals with high melanin concentrations that protect against UV. Therefore population evolved towards high melanin densities in the skin.
Answer:
The correct answer is option b. "Alpha eventually replaced by theta".
Explanation:
Electroencephalogram (EEG) techniques allows researchers to monitor the phases of sleeping according of what brain waves are seen in the equipment. A normal adult connected to EEG will respond with alpha waves during a wakeful state. However, as the person becomes drowsy and enters to the first stage of sleep, the alpha waves will be eventually replaced by theta waves. Theta waves are the dominant waves during sleeping, and also could be seen during deep meditation.
A gymnosperm is <span>a plant that has seeds unprotected by an ovary or fruit. Gymnosperms include the conifers, cycads, and ginkgo.</span>
Answer:
Lipid
Explanation:
Lipids are composed of a glycerol molecule bonded to long hydrocarbon chain(s) (can be single or multiple) and, depending on the lipid, to other molecules—such as a phosphate group (phospholipids). ... Fats Fats consists of glycerol and 3 fatty acids.