Characteristics of Living Things Unit 2 It’s Alive! Or Is It? What is Life? Section 2.1 • There are 7 characteristics that all living things must have in order to be considered alive. The 7 Characteristics of Life 1. Response to Stimuli • All living things can respond/react to stimuli whether it is internal or external. The 7 Characteristics of Life 2. Adaptability • In order to survive all living things must be able to adapt to their environment and evolve over time. The 7 Characteristics of Life 3. Reproduction • All living things can reproduce. The 7 Characteristics of Life 4. Energy Use • All living things must be able to use energy to perform the tasks necessary for survival. The 7 Characteristics of Life 5. Homeostasis • All living things can maintain a balanced internal environment. The 7 Characteristics of Life 6. Organization • All living things have cellular organization. • They are made up of one or more cells. The 7 Characteristics of Life 7. Growth and Development • All living things grow (get bigger) and develop (become more complex). R.A.R.E. H.O.G • • • • • • • R esponse to stimuli A dapatability R eproduction E nergy Use H omeostasis O rganized by cells G rowth and development Life Comes From Life Redi’s Experiment Life Comes From Life Pasteur’s Experiment What Living Things Need to Survive 1. Food: Organisms need food as a source of energy. – Organisms that can make their own food are called autotrophs. – Organisms that need to eat other organisms as food are called heterotrophs. What Living Things Need to Survive 2. Water: Living things can only survive a few days without water. What Living Things Need to Survive 3. Space: All living things need a space where they can find food, water and shelter.