IG Lecture Outlines 1-1 Chapter 1 Exploring Life Lecture Outline Overview •Biology is the scientific study of life. •You are starting your study of biology during its most exciting era. •The largest and best-equipped community of scientists in history is beginning to solve problems that once seemed unsolvable. °Biology is an ongoing inquiry about the nature of life. •Biologists are moving closer to understanding: °How a single cell develops into an adult animal or plant. °How plants convert solar energy into the chemical energy of food. °How the human mind works. °How living things interact in biological communities. °How the diversity of life evolved from the first microbes. •Research breakthroughs in genetics and cell biology are transforming medicine and agriculture. °Neuroscience and evolutionary biology are reshaping psychology and sociology. °Molecular biology is providing new tools for anthropology and criminology. °New models in ecology are helping society to evaluate environmental issues, such as the causes and biological consequences of global warming. •Unifying themes pervade all of biology. A. Exploring Life on Its Many Levels •Life’s basic characteristic is a high degree of order. •Each level of biological organization has emergent properties. •Biological organization is based on a hierarchy of structural levels, each building on the levels below. °At the lowest level are atoms that are ordered into complex biological molecules. °Biological molecules are organized into structures called organelles, the components of cells. °Cells are the fundamental unit of structure and function of living things. •Some organisms consist of a single cell; others are multicellular aggregates of specialized cells. •Whether multicellular or unicellular, all organisms must accomplish the same functions: uptake and processing of nutrients, excretion of wastes, response to environmental stimuli, and reproduction. °Multicellular organisms exhibit three major structural levels above the cell: similar cells are grouped into tissues, several tissues coordinate to form organs, and several organs form an organ system.