Why is there a limit to the number of levels that a food chain can reach

Pls me i need this ! each cell has genes activated depending on it's job and what kind of cell it is. it is the presence of that causes the repressor protein to fall off and unblock the gene on the lac operon. if a gene is turned on then it is being an additional circular chromosome found in some bacteria that is used in genetic engineering.

Abacteriophage typically attaches to the bacterium and then

Put the processes of the water cycle in the correct order starting at the point where the water is in a lake