Answer:
B
Explanation:
because they are moving at the same direction
To make ATP, cells must join together ADP & a phosphate using energy from food. A phosphate is removed from an ATP molecule in order to provide energy for the cell. Thus, the ATP molecule turns into an ADP molecule. We eat food which gives us energy to add another phosphate group to the ADP molecule, turning it into an ATP molecule. The cycle then begins again.
The answer is A, Viruses
Viruses cannot reproduce on their own , so they have to inject their DNA or RNA into the nucleuus of a cell. By doing this, the virus will take over that cells and within times, that cells will pop up and producing more viruses.
This reproduced virus will repeat the same process until our immune systems stop them
