Answer:
Secondary succession is the series of community changes which take place on a previously colonized, but disturbed or damaged habitat. Examples include areas which have been cleared of existing vegetation (such as after tree-felling in a woodland) and destructive events such as fires.
A is the correct answer I belive
Asexual means by self sexual means from opposite genders
The effect of such toxic chemicals to the body is that they stimulate uncontrolled cell division. Uncontrolled cell division or cells proliferation may lead to cancer. The unchecked cell growth results to mutations in genes that can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death.