Cyanobacteria don't need oxygen to survive they produce oxygen. They where the first ever known organisms on the planet and they produced oxygen in the oceans which was absorbed by iron deposits and then once the iron had oxygen the ocean got the oxygen until it got into the atmosphere and Eukaryota bacteria evolved. So the answer would be: <span>They convert nitrates from the water into nitrogen gas (N2) that is released into the atmosphere.</span>
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. The word galaxy is derived from the Greek galaxias, literally "milky", a reference to the Milky Way.
Elliptical: These have a faint, rounded shape, but they're devoid of gas and dust, with no visible bright stars or spiral patterns. ...
Spiral: The Milky Way is one of the larger spiral galaxies. ...
Irregular: These are small, faint galaxies with large clouds of gas and dust, but no spiral arms or bright centers.
Answer:
D. an entire chromosome is added to a chromosome set
Explanation:
The rest of these are mutations in the DNA sequence
