1. What is Life? Ms. Levasseur Biology

2. What Characteristics Do All Living Things Share?  Matter – the stuff everything is made of  What is the difference between living matter and nonliving matter?  No one characteristic is enough to describe a living thing

3. Living things are made of Cells  Cells are the basic unit of life  Each life form begins from one cell  The cell divides many times  Cells differentiate  Cells organize to form the final organism  Each cell type has a specific job  Eye cells, heart cells, lung cells, blood cells, bone cells, liver cells, etc.  Cells contain DNA – the universal genetic code

4. Living Things Obtain and Use Energy  The sum of the chemical energy they use is called metabolism  Autotrophs - use energy from the sun to make their own energy  Heterotrophs - must ingest food to make energy

5. Living Things Maintain Homeostasis  Homeostasis - stable internal conditions which must be maintained in order to remain alive  Some of these conditions include temperature, water content, and heartbeat  A certain level of energy must be kept within the body at all times which is why animals must ingest food on a regular basis  Energy flows through systems but nutrients cycle

6. Living Things Grow and Develop  Cells divide to form new, identical cells  More cells = bigger organism  Differentiation happens when cells mutate into other types of cells, making a more complex organism  When organisms grow, change, and become more complex it is called development  Single-celled organisms do grow as well, but they will only become slightly larger – this is nearly immeasurable

7. Living Things Reproduce  They must reproduce in order to continue the species  Two types of reproduction  Sexual - combining genetic information  DNA from mom mixed with DNA from dad  Asexual - splitting into two organisms (cloning)  The new organism is an exact copy of the first  Sometimes, not every member of a species is able to reproduce  as long as others are able to it will not threaten the species  Mules are a bizarre anomaly