Module 1: How to Define Life The Nature of Biology Module 1: How to Define Life

How do you know something is alive? A. Biology means the study of (-ology) all life (bio-) and includes many branches. B. Biologists organize living things into kingdoms. There are currently six kingdoms Kingdom Example Archaebacteria Extremophile bacteria Eubacteria Typical bacteria Protista Seaweed, Amoeba, Slime Mold Fungi Yeast, Mushrooms Plantae Moss, Fern, Holly, Oak tree Animalia , Fish, Birds, Frogs, Humans

How do you know something is alive? C. Characteristics of Life - Alive! Videoclip 1. Organization (The level of complexity) a. Organism Organ System Organs Tissues Cells Molecules Atoms / Elements Meet the Elements - They Might Be Giants

How do you know something is alive? b. All living things need six essential elements (atoms): Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur (CHNOPS) c. All living things are made of cells. i. One-celled organism – unicellular ii. Many-celled organism - multicellular

How do you know something is alive? 2. Energy Use a. Organisms need energy constantly to build molecules (synthesis) and cells and to break down (digest) substances (such as breaking down food for nutrition) b. Organisms must transport nutrients to be used in cellular respiration to produce energy. c. An organisms’ chemical reactions are called its metabolism

How do you know something is alive? 3. Reproduction a. Organisms must replace themselves so the entire species will survive. b. May be asexual (only one individual contributes genetic material) or sexual (two individuals contribute genes).

How do you know something is alive? 4. Growth and Development a. Growth – to increase in size. Increases the number of cells of a multicellular organism. b. Development – change that takes place in structure and function of an organism during its life cycle. Example: Embryo becomes a fetus

How do you know something is alive? 5. Respond to Stimuli a. A quick, non-permanent change b. Stimulus – any condition that causes an organism to react. Example – A loud noise (stimulus) causes your dog to run under the bed (response).

How do you know something is alive? 6. Adjust to Environment a. Homeostasis - the regulation of an organism’s internal environment to maintain conditions suitable for life Ex: Getting rid of wastes by excretion

How do you know something is alive? b. An adaptation is an inherited structure, behavior, or internal process that enables organisms to better survive an environment. Ex: Gills on a fish

Life Processes: STERNGRR Synthesis – making materials Transport – moving materials Excretion – getting rid of wastes Respiration – gas exchange AND production of energy (ATP) Nutrition – gaining and using energy from food Growth and Development – getting bigger and/or changing Regulation – controlling internal processes Reproduction – producing new cells or new organisms