As of 2014, it was often reported in popular media and in the scientific literature that there are about 10<span> times as many microbial cells in the human body than there are human cells; this figure was based on estimates that the human microbiome includes around </span>100 trillion<span> bacterial cells and an adult human</span>
Secondary succession generally takes place faster in comparison to primary succession as the substrate is already present. In the case of primary succession, there is no soil and it consumes much time to form.
Primary succession takes place in mainly lifeless regions, that is, the regions in which the soil does not possess the tendency of sustaining life as an outcome of various factors.
On the other hand, secondary succession takes place in the regions where a community that previously prevailed have been eradicated and is epitomized by smaller scale turbulence, which do not eradicate all the forms of life and nutrients from the environment.
How a bridge is built at the base can affect how far it can extend.
Explanation:
The modern theory of chemical evolution is based on the assumption that on a primitive earth a mixture of simple chemicals assembled into more complex molecular systems, from which, eventually came the first functioning cell(s).