Animal+Plant in jar help?

Question

A plant sealed in an air tight jar will die in about a week. An animal placed in a similar jar will die in a matter of hours.

What is the cause of the plant’s death? The animal’s death? Would the survival times for these organisms change if they were placed in the same sealed jar?
What caused the animal and plants deat?
What experimental conditions could exist?

Answer 1

The plant dies because it has used up the carbon dioxide needed for photosynthesis. I expect it would take longer than a week, though.

The animal dies because it has used up the oxygen.

If the plant is big enough and the animal is small enough, they could survive together in the jar because they would meet each other's needs for carbon dioxide and oxygen. Don't forget that the animal needs to eat something, though. So if the animal is a type that eats up the plant, then the balance is all off.

Experimental conditions:
1. amount of light
2. type and size of plant
3. aquatic or terrestrial ecosystem
4. type and size of animal