Your biological clock isn’t just what ticks down your days for baby-bearing.

“The biological clock is a mechanism inside most organisms that allows them to tell the time of day,” Jonathan Arnold, professor of genetics, said in a phone interview. “Reproduction, waking and sleeping, hormone levels and even your mood to some extent are all under clock control.”

The term “biological clock” is often used interchangeably with “Circadian rhythm,” which can be thought of as an approximately 24-hour cycle in the behavioral, biochemical and physiological processes of organic life forms.

Arnold will lead a seminar sponsored by the Department of Genetics focused on “Systems Biology of the Biological Clock” today from 4 p.m. to 5 p.m. in room S175 of the Paul D. Coverdell Center.

Arnold, who earned a doctorate from Yale University, has been engaged in research involving microorganisms, which was begun several years ago by Cara Altimus, a former University undergraduate.

The research involves specific microbes that grow on bread when it is stored improperly. By manipulating their environment as well as light and dark cycles, Arnold said he wants to gain a more thorough understanding of how the biological clock operates within these primitive forms of life. By scrutinizing the biological processes of the evolutionary ancestors of humans, Arnold said he hopes to shed light on the processes at work in human minds and bodies.