This lecture introduces you to studying life. In this chapter, we will address the following questions: What is biology? How is all life on earth related? How do biologists investigate life? How does biology influence public policy? | Studying Life 1 Studying Life What Is Biology? How Is All Life on Earth Related? How Do Biologists Investigate Life? How Does Biology Influence Public Policy? What is Biology? Biology: the scientific study of living things Living things: all the organisms descended from a single-celled ancestor. What is Biology? Characteristics of living organisms: Consist of one or more cells Contain genetic information Use genetic information to reproduce themselves Are genetically related and have evolved What is Biology? Characteristics of living organisms: Can convert molecules from their environment into new biological molecules Can extract energy from the environment and use it to do biological work Can regulate their internal environment What is Biology? Evolution: a central theme Living systems evolve through differential survival and reproduction. Figure The Many Faces of Life (Part 1) Figure The Many Faces of Life (Part 2) What is Biology? Unicellular organisms: a single cell carries out all the functions of life Multicellular organisms: made of many cells that are specialized for different functions Figure All Life Consists of Cells The study of cells was made possible by the invention of the microscope. What is Biology? Cell Theory: Cells are the basic structural and physiological units of all living organisms. Cells are both distinct entities and building blocks of more complex organisms. (Schleiden and Schwann 1838) What is Biology? Cell Theory: All cells come from preexisting cells. All cells are similar in chemical composition. Most of the chemical reactions of life occur within cells. Complete sets of genetic information are replicated and passed on during cell division. What is Biology? Charles Darwin proposed that all living organisms are descended from common ancestors. Evolution by natural selection What is Biology? Species: a group of organisms that look alike and can breed successfully with one | Studying Life 1 Studying Life What Is Biology? How Is All Life on Earth Related? How Do Biologists Investigate Life? How Does Biology Influence Public Policy? What is Biology? Biology: the scientific study of living things Living things: all the organisms descended from a single-celled ancestor. What is Biology? Characteristics of living organisms: Consist of one or more cells Contain genetic information Use genetic information to reproduce themselves Are genetically related and have evolved What is Biology? Characteristics of living organisms: Can convert molecules from their environment into new biological molecules Can extract energy from the environment and use it to do biological work Can regulate their internal environment What is Biology? Evolution: a central theme Living systems evolve through differential survival and reproduction. Figure The Many Faces of Life (Part 1) Figure The Many Faces of Life (Part 2) What is Biology? .
