The answer to number 6 is a.
Answer:
Septic tanks and oxidation ponds
Explanation:
These system of wastewater treatment and disposal are not too feasible in large municipalities because of the presence of sewer system that has been made available by government, in order to mitigate the possibilities of transmitting enteric diseases that are very harmful to human health.
The gene transfer process in bacteria is also commonly known as the "horizontal gene transfer." In this process, the DNA of a bacteria is transferred from one bacterium to another virus, through a plasmid from a donor cell to a recipient cell.
An endangered species is a type of species in which this type of organism has decreasing numbers and are dangerously close to going extinct. Invasive species are species in which an organism invades an environment where it is not native to, and take over the ecosystem. Local species are species in which the organism is native to that environment and plays a key role in that ecosystem. A keystone species is a species in which the organism is a key part of that ecosystem to thrive; without it, the ecosystem would collapse
