Nature of Life – 8 Characteristics OL Nature of Life – 8 Characteristics Overview Made of Cells Response to Environ. Homeostasis Ability to reproduce There are 8 characteristics of all living things. You must have all 8 to be considered alive Basic unit of any organism considered to still be alive Unicellular organisms- only made of 1 cell- Ex. Bacteria Multicellular organisms- 2 or more cells- Ex. Humans All organisms respond physically to environmental changes Ex. Sweating, shivering Regulation of one's internal environment through either internal or external mechanisms Ex. temperature, heart rate, blood sugar, fluid levels Passing down of traits from generation to generation Asexual reproduction- produces clones Sexual reproduction- produces genetically unique offspring

Nature of Life – 8 Characteristics OL Nature of Life – 8 Characteristics Grow and (Develop)‏ Metabolism Adapt/ Evolve Genetic Code Growth- a physical increase in size-done by all organisms Ex. a bacteria cell growing before it divides, Development- a change in physical appearance- done by most organisms Ex. Puberty, Tadpole to frog, etc. The sum of all chemical reactions that occur in an organism Ex. Digestion, making muscle, etc. Organisms well suited to their environment survive and reproduce, passing traits down to their offspring, who will ultimately be better adapted to that same environment As a species, this leads to evolution, which is defined as change in a species over time. Individuals CANNOT evolve-we are born as we are. But over time generations of better adapted offspring will lead to a population that looks different than it did 50 years ago. All organisms are controlled by the same Universal Genetic Code The DNA that gives you your traits is made of the exact same pieces that give an elephant its traits, just in a different order

Nature of Life – Levels of Organization OL Nature of Life – Levels of Organization Basic living unit. Anything smaller is not considered alive. Ex. Schwann Cell (found in Nervous system)‏ Groups of cells working together to preform a function Ex. Nervous tissue- includes Scwhann cells and others but all work to help receive stimuli and send out responses Groups of tissues working together to preform a function Ex. Brain- works to turn sensation of hand on hot pan into action of removing hand from hot pan Groups of organs working together to preform a function Ex. Brain, spinal cord, and nerves all work to make the pain lead to an action Sum of all the organ systems in an individual, which work together to achieve life Ex. Humans, but technically any living thing. Cells Tissues Organs Organ Systems Organism

Nature of Life – 8 Characteristics GT Nature of Life – 8 Characteristics Overview Made of Cells Response to Environ. Homeostasis Ability to reproduce Grow and (Develop)‏ Metabolism Adapt/Evolve Genetic Code 8 COL's- must have all 8 to be alive Basic living unit Unicellular- only 1 Multicellular- >/= 2 Respond physically to 's- Stimulus/Response Regulation of internal environment Internal or external mechanisms Passing down traits gen. to gen. Asexual=clones Sexual=unique Physical increase in size-done by all vs. Change in appearance-done by most Chemical reactions w/in an organism Well suited to environment = survive and reproduce = passing traits to offspring Leads to evolution (change in a species over time). DNA pieces same for all but diff order

Nature of Life – Levels of Organization GT Nature of Life – Levels of Organization Atoms Molecules Compounds Macro- molecule Organelle Cells Tissues Organs Organ Systems Organism Basic unit of matter >/= 2 of same atom >/= 2 of diff atom Proteins, Carbohydrates, Fats, DNA/RNA Parts of cell Basic living unit Groups of cells that together preform a function Groups of tissues that together to preform a function Groups of organs that together preform a function Sum of all organ systems-work together to achieve life Any living thing.