The structure found in all cells that acts like a barrier of the cell controlling what enters and leaves the cell

The answer to that is the cell membrane. The way that I remember all of the cell parts is through an analogy. Many have been made, but for me the easiest one to understand is a city. It takes a long time to explain all of the cell parts compared to a city, so if you are interested just look up "cell analogy to a city". But the cell membrane can be compared to a gate inside of a city :)

a chair, a bed, and a toothbrush

explanation:

1. a host loses nutrients to a parasite

2. a parasite only benefits when the host is alive (cause if the host dies the parasite dies with it )

3. producers to consumers

4. the tapeworm is a parasite

5. they convert energy from the sun (photosynthesis)

6. sunflower-robin (i think im 80% sure)

7. producer

8. consumer

9. prey

10. fresh water snails ( cause the green algea is the producer and the snails are the primary consumers and the small fish consumer so is the big fish)