Chapter 1: Explain how science is discovered
List the characteristics used to define life
Explain the concept of emergent properties and how it applies to living things Explain the difference between hypothesis and theory
Outline the scientific method
Use the theory of evolution to explain how science is discovered Explain the main concepts that unify biology
Biology unifies much of natural science
The study of biology is a point of convergence for the information and tools from all of the natural sciences. Biological systems are the most complex chemical systems on Earth, and their many functions are both determined and constrained by the principles of chemistry and physics. Biological systems do not represent any new forms of matter, and yet they are the most complex organization of matter known. The complexity of living organisms is made possible by the constant source of energy—the Sun. Life defies simple definition
In its broadest sense, biology is the study of living things—the science of life. The seven characteristics shared by living systems:
Cellular organization: All organisms consist of one or more cells. Often too tiny to see, cells carry out the basic activities of living. Each cell is bounded by a membrane that separates it from its surroundings. Ordered complexity: All living things are both complex and highly ordered. Your body is composed of many different kinds of cells, each containing may complex molecular structures. Sensitivity: All organisms respond to stimuli. Plants grow toward a source of light and the pupils of your eyes dilate when you walk into a dark room. Growth, development and reproduction: All organisms are capable of growing and reproducing, and they all possess hereditary molecules that are passed to their offspring, ensuring that the offspring are of the same species. Energy utilization: All organisms take in energy and use it to perform many kinds of work. Every muscle in your body is powered with energy you obtain from you diet. Homeostasis: All organisms maintain relatively constant internal conditions that are different from their environment. Evolutionary adaptation: All organisms interact with other organisms and the nonliving environment in ways that influence their survival, and as a consequence, organisms evolve adaptations to their environments. Living systems show hierarchical organization
The organization of the biological world is hierarchical—that is, each level builds on the level below it. 1. The Cellular Level: Atoms, the fundamental elements of matter, are joined together into clusters called molecules. Complex biological molecules are assembled into tiny structures called organelles within membrane bounded units we call cells. The cell is the basic unit of life.
Many independent organisms are composed only of single cells. Bacteria are single cells.
All animals and plants, as well as, most fungi and algae, are multicellular—composed of more than one cell. 2. The Organismal Level: Cells in complex multicellular organisms exhibit three levels of organization. The most basic level is that of tissues, which are groups of similar cells that act as a functional unit. Tissues, in turn, are grouped into organs—body structures composed of several different tissues that act as a structural and functional unit. At the third level of organization, organs are grouped into organ systems. 3. The Populational Level: Individual organisms can be categorized into several hierarchical levels within the living world. The most basic of these is the population—a group of organisms of the same species living in the same place. All populations of a particular kind of organism together form a species, its members similar in appearance and able to interbreed. At a higher level of biological organization, a biological community consists of all the populations of different species...
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