Causes. Sunburn results when the amount of exposure to the sun or other ultraviolet light source exceeds the ability of the melanin to protect the skin. Melanin is the skin's protective coloring (pigment).kin cancer usually appears in adulthood. But it is caused by sun exposure and sunburns that began as early as childhood. You can help prevent skin cancer by protecting your skin and your children's skin from the harmful rays of the sun.
The angiosperms, or flowering plants, are one of the major groups of extant seed plants and arguably the most diverse major extant plant group on the planet, with at least 260,000 living species classified in 453 families (Judd et al., 2002; APG II, 2003; Soltis et al., 2005).
In common terms, angiosperms are all flowering plants. They are distinguished from gymnosperms, by their ability to flower and produce seeds enclosed in fruits. There are a few other characteristics that are discussed in the following paragraphs.s you can see, angiosperms are dicots (flower with stamens and pistils in separate flows on same or different plant) and monocots (stamens and pistils on the same flower). The root and shoot system is the prime feature of angiosperms. They are the major food sources for animals as well as humans.