Leon Tsai Mr. Helms Biology I – Per. B Stuart Hall High School The Case for Life Leon Tsai Mr. Helms Biology I – Per. B Stuart Hall High School

Dead or Alive? At first glance, most people would automatically know the images on the left column are of living things What separates these from the things on the right column?

Got Life? Body composed of cells No one scientist can unanimously agree on a single comprehensive answer to defining life Levels of organization Response and adaptation to the environment Usage of energy Merriam-Webster defines life as “the quality that distinguishes a vital and functional being from a dead body” Dependence on water Maturation Capability of reproduction Inability to decay Living vs. Nonliving

Cells Cells = building blocks of life According to the Cell Theory: All living things are made up of cells Cells are the basic units of structure and function in living things Living cells come only from other living cells

Reproduction Reproduction is the act of producing offspring It is the way of continuing our species In many ways, reproduction is, essentially, the core purpose of our existence

Life… Elsewhere When asked whether there life exists outside earth, NASA JPL director Charles Elachi said, “I think absolutely”. Elachi continues, “We have the same laws of chemistry, physics. If there are any locations where there are the basic ingredients, there should be the basic ingredients for life”.

Titan and Europa Titan (moon of Saturn) and Europa (moon of Jupiter) are two of the likeliest places to find life outside earth Both moons contain am abundance of liquid water Both have relatively unstable temperatures

Purpose Why does life exist? Every person has a different perspective in regards to the point of our existence The question of our life is not just a scientific question, it digs even deeper It is a question that is scientific, religious/spiritual, and ultimately, personal

Thank You!

Works Cited "The 7 Characteristics of Life." NMT.edu. New Mexico Institute of Mining and Technology, n.d. Web. 11 Sept. 2013. <http://infohost.nmt.edu/~klathrop/7characterisitcs_of_life.htm>. "Cell Theory." CPSchools.com. Chesapeake Public Schools, n.d. Web. 11 Sept. 2013. <http://www.cpschools.com/Schools/OSM/theory.htm>. Kiefer, Walter S. "Europa and Titan: Oceans in the Outer Solar System?" LPI.USRA.Edu. Lunar and Planetary Institute, n.d. Web. 26 Aug. 2013. http://www.lpi.usra.edu/science/kiefer/Education/SSRG2- Europa/europa.html. Mullen, Leslie. "Defining Life." AstroBio.Net. Astrobiology Magazine, 19 June 2002. Web. 11 Sept. 2013. http://www.astrobio.net/exclusive/226/defining- life. Swaby, Rachel. "Is There Life Beyond Earth? 'I Think Absolutely,' Says NASA JPL Director." TheAtlantic.com. The Atlantic, 30 Oct. 2012. Web. 11 Sept. 2013. <http://www.theatlantic.com/technology/archive/2012/10/is- there-life-beyond-earth-i-think-absolutely-says-nasa-jpl-director/264308/>.