![](https://www.opentextbooks.org.hk/sites/opentextbooks/files/book_profile/cc_icon/by-sa.png)
Available under Creative Commons-ShareAlike 4.0 International License.
Even the smallest organisms are complex and require multiple regulatory mechanisms to coordinate internal functions, such as the transport of nutrients, response to stimuli, and coping with environmental stresses. For example, organ systems such as the digestive or circulatory systems perform specific functions like carrying oxygen throughout the body, removing wastes, delivering nutrients to every cell, and cooling the body.
- 2695 reads