Answer:
Cyanobacteria, Anabaena and Azotobactor are called Nitrogen fixing bacteria. These bacteria change the nitrogen in the atmosphere into a form that is used by the plants to make proteins. Plants take nitrogen in the form of nitrates. The atmospheric nitrogen is first converted into ammonia after that ammonia is converted into nitrates and this nitrates use by the plants to make proteins.
The answer is invasive species.
Invasive species are species that are not native to specific ecosystem,
but they have a capability to spread widely through the ecosystem, This way
they can threaten native species of the ecosystem or cause
environmental harm.
<span>After being introduced into the Black Sea, they greatly affect local
ecosystem. In the new area, they have no natural predators and are able to
spread. If they spread beyond the area they are introduced, they
become invasive species which can overgrow native biotopes and are
a great threat to the local biodiversity. This could lead to the extinction
of some native species.</span>
SI units are a modern form of the metric system.
Answer: a small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.
Explanation: