What Does it Mean to Be Alive? The Characteristics of Life

Biology = the study of life There are 8 characteristics of life To be considered living, organism must exhibit all 8. No single characteristic is enough to describe a living thing.

Life!!! All living things share some basic properties. Cellular Organization Reproduction Metabolism (Obtain and Use Energy) Homeostasis Heredity Responsiveness Growth and Development Adapt Through Evolution

All Living Things are Made Up of Cells  All Living Things are Made Up of Cells Smallest unit capable of all life functions Unicellular Organisms Entire organism is made up of one single cell Bacteria

Multicellular Organisms The organism is made up of many cells Cells have specialized functions within the organism

All Living Things Reproduce  All Living Things Reproduce Reproduction is the process of producing new organisms of the same type Asexual Reproduction A single parent organism reproducing by itself Offspring is identical to parent

Sexual Reproduction Two different parent organisms contribute genetic information Offspring is unique from both parents

All Organisms are based on a Genetic Code  All Organisms are based on a Genetic Code DNA is the genetic code found in every cell DNA contains Genes Genes carry hereditary information DNA is inherited from parents and controls traits (it’s the reason you resemble your parents).

All Living Things Grow and Develop  All Living Things Grow and Develop Growth means to get bigger in size

All Living Things Grow and Develop  All Living Things Grow and Develop Development involves a change in the physical form or physiological make-up of an organism

All Living Things Obtain and Use Energy  All Living Things Obtain and Use Energy Living organisms need energy to grow, develop, repair damage, and reproduce

 Metabolism the combination of chemical reactions through which an organism builds up and breaks down materials as it carries out life processes

All Living Things Respond to Their Environment  All Living Things Respond to Their Environment An example is a plant’s leaves and stems growing toward light Organisms react to stimuli: Light Temperature Odor Sound Gravity Heat Water Pressure

All Organisms Maintain Homeostasis  All Organisms Maintain Homeostasis Homeostasis = the process of keeping the internal environment stable/balanced/constant despite changing conditions around the organism Body temperature Blood volume pH balance Water balance

All Living Things Change Over Time  All Living Things Change Over Time Evolution: adapting to the environment Adaptation A process that enables organisms to become better suited to their environment Species obtain adaptations through evolution over hundreds, thousands, and millions of years