What year did theodor schwann contribute to the cell theory

Which of the four major uses is predicted to change the least by 2020?

Study the diagram of a desert food chain . what would most likely happen if the kangaroo rats were killed off and removed from the food chain ?

Photosynthesis uses co2 and cellular respiration produces co2. we call the point when the two processes are in balance--when there is no net production of co2--the compensation point. how might you limit one of the processes in order to achieve a compensation point?