I think tissue or a nucleus
Answer:
a cell in a plant that is composed of a cell wall and multiple organelles, like a huge vacuole and chloroplasts that carry out photosyntheses. They are the building blocks for plants.
Explanation:
An error is that the scientist did not control their variables. They had one group of people playing the game at 6, and another group playing at 12. This means that other things might have affected the scores other than what was being tested, which was caffeine.
politics because politics is one of the major things