Cells are the most simple level of organization, as tissues contain cells, organs contain tissues and systems contain organs, so R would be your answer.
6)active immunity occurs when the person is exposed to a live pathogen and passive immunity<span> can occur naturally.
7) you can buy bacteria killing soap and keep your house bacteria free. wipe down everything that hands touch everyday.
hope this </span>helps. :)
Answer:
The correct option is cell wall and central vacuole.
Explanation:
The cell wall can be described as an additional membrane around the cell membrane which is present in the plant cells but is absent in animal cells.
The plant cells also have a vacuole located at the center on the cell. The central vacuole is absent in animal cells. It stores the waste and other materials for the plant cell. The plant vacuole also provides support to the cell.
B) Billowy sheep-like clouds.
Well theory isnt proven. It means you have a strong idea about the subject your talking about. So if a scientist finds evidence that suggests something against the theory then it can be changed.