Cyanobacteria released OXYGEN into the atmosphere through photosynthesis
The correct answer is B. Oxygen.
Oxygen, as a part of the atmosphere, also participates in UV protection, besides being necessary for breathing.
First answer is correct. Eutrophication can have serious effects, like algal blooms that block light from getting into the water and harm the plants and animals that need it. If there's enough overgrowth of algae, it can prevent oxygen from getting into the water, making it hypoxic and creating a dead zone where no organisms can survive.
Answer:DNA replication occurs in the cytoplasm of prokaryotes and in the nucleus of eukaryotes.
Explanation: Regardless of where DNA replication occurs, the basic process is the same. The structure of DNA lends itself easily to DNA replication. Each side of the double helix runs in opposite (anti-parallel) directions.