When animals eat the food is stored and digested
in the stomach or a similar structure but when a unicellular organism lie the paramecium eats the food is stored in which organelle

The best answer would be:

The vacuole

Here is more about your question:

Unicellular organisms have a food vacuole. A paramecium for example, would draw food to itself and when the food enters the body a vacuole will encapsulate it. It is in the vacuole where the food will be slowly digested. The vacuole will travel around the cell and at the same time diffuse the nutrients needed by the cell.

answer: accepted answer: aquatic animals use the oxygen dissolved in water to carry out respiration. since the amount of dissolved oxygen in water is low as compared to the amount of oxygen in the air, therefore the rate of breathing in aquatic animals is much faster than it is in terrestrial animals.

explanation:

not sure if this is what you'r looking for eubacteria and archaebacteria