The answer is; A
The active site of the enzyme is bound by a substrate and probably the enzyme catalyzes a hydrolysis reaction. The poison mimics the substrate and competes with the substrate for the active site of the enzyme. The poison may bind permanently to the enzyme rendering the enzyme unavailable for other substrates. This could make a particular biochemical reaction, in which the enzyme is involved, to reduce drastically hence threatening life.
A common pioneer organism<span> in a primary </span>succession<span> is the. icº, ) - 3. The final stable state of a </span>succession is called the<span> (Mººp community</span>
Cyanobacteria or simply known as blue-green algae may have formed the oxygen into the early atmosphere. This is because these micro-organism has the capability to photosynthesize wherein they can produce oxygen and carbohydrates. In fact, all the plants contribute in the fomation of oxygen.