The 8 Unifying Characteristics of All Living Things What do you have in common with a bird, fish, tree, ringworm, and the green stuff on the inside of a fish tank?

On your whiteboard write down any characteristic that all living things have.

All living things …. Have a universal genetic code Are made of cells Require and use energy Maintain Homeostasis Grow and develop Respond to their environment (stimuli) Reproduce Evolve What, exactly, do these mean??

All living things …. (1) Have a Universal Genetic Code All living things store information in a genetic code written in the DNA molecule. Genetic information is copied and passed from parent to offspring Life’s genetic code is responsible for most of our traits and is almost the same in all living things – but for a few small differences.

All living things …. (2) are Made of Cells Cells = the smallest units considered fully alive One cell = unicellular; or Many cells = multicellular Prokaryotic - Do not contain any membrane-bound organelles, including a nucleus (bacteria) Eukaryotic – Contain membrane-bound organelles such as a nucleus (everything else..plants, animals, etc)

All living things …. (3) Require and Use Energy Take in and convert materials for energy in order to grow, develop, reproduce, maintain homeostasis….etc. All living things require an energy source Autotrophs (Chemoautotrophs or photoautotrophs) – get energy from inorganic sources (sun or inorganic compounds like hydrogen sulfide) Heterotrophs (Carnivores, herbivores, omnivores) – get energy from consuming organic compounds as food Autotrophs (Chemoautotrophs or photoautotrophs) Heterotrophs (Carnivores, herbivores, omnivores)

All living things …. (4) Maintain Homeostasis Homeostasis = a stable (or balanced) internal environment Some examples : pH, Wastes, Temperature, Ions, Water In order to achieve balance, living things need to sense and respond to changes to keep a constant internal environment. The brain detects a change and sends an appropriate response to either increase or decrease a function so it returns to normal.

All living things …. (5) Grow & Develop Includes complexity of an organism (levels of organization) Cells, tissues, organs, organ systems, organisms Growth = getting bigger Development = getting more complex

All living things …. (6) Respond to their Environment All organisms notice and react to stimuli (such as other organisms) from their environment Stimulus: A signal to which a living thing reacts Response: A reaction to a stimulus Behavioral response – one that an organism chooses to do/controls Physiological response – one that an organism can’t control; happens automatically Ex. Turn off light

All living things …. (7) Reproduce Sexual reproduction (combining DNA from 2 parents); offspring are genetically different from the parents Asexual reproduction (DNA from only 1 parent); offspring are genetically identical to the parent

All living things …. (8) Evolve All populations of livings things evolve, or change slowly over long periods of time Natural selection – the process by which evolution occurs; “survival of the fittest” – organisms best suited to their environment will survive longer & reproduce more Adaptations – beneficial traits that allow living things to survive and reproduce Descent with modification – related organisms share a common ancestor