Answer:
Some differences between primary and secondary succession are:
-Secondary succession happens on a previously existing community that has been cleared.
Another difference would be:
-Pioneer species for secondary succession are adapted differently- they grow quickly, can disperse quickly and have a short life span
And finally:
-Primary succession develops a new community from scratch
Not sure if you were looking for this, sorry if this is not correct.
Answer:
Genetic, geographic & cultural factors that cause sickle-cell anemia. It is important to note that even genetic diseases are caused by multiple social, environmental and biological factors. This is particularly true in the case of sickle-cell anemia, a genetically inherited blood disorder usually found in people with West African ancestry (PBS 2001).
There are 6 elements that are the most important. The acronym, CHNOPS, is an easy way to remember these.
C - Carbon
H - Hydrogen
N - Nitrogen
O - Oxygen
P - Phosphorous
S - Sulfur