Coursework.Info - Inspiration in an Instant

On the left is an image preview of every page of this document, and below are the first 150 words with formatting removed:

Emily 12JS Comparing and Contrasting Gas Exchange 25/01/02 in Humans, Protozoa and Plants Introduction: This essay aims to compare and contrast gas exchange in the above organisms in terms of complexity, size and efficiency. Note that: Protozoa: Are a group of single-celled organisms, which belong to the kingdom Protoctista e.g. amoeba. Comparing the structure of gas exchange systems in the three organisms: Humans and plants have complex gas exchange systems compared to those in protozoa. The three diagrams below show the basic structure of the three organisms. Comparing the mechanisms of the three organisms' gas exchange systems: The most simple gas exchange system is present in protozoa. Gas exchange occurs across the whole surface of the organisms by diffusion; the movement of molecules from an area of high concentration to an area of low concentration across a semi-permeable membrane. In this case, it is the movement of carbon dioxide and oxygen across a plasma membrane, the...

To see the full version of this document, and 144,790 others