1. A seed leaf - cotyledon
2. A flowering plant with seeds that have two seed leaves - dicotyledon
3. A food storage tissue - endosperm
4. A flowering plant with seeds that have one seed leaf cotyledon - monocotyledon
Key is to lock as D. Substrate is to active site.
Increases genetic variation of the offspring.
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.
