Biology 2e Chapter 1 The Study Of Life PDF

BIOLOGY 2e Chapter 1 THE STUDY OF LIFE Lecture PowerPoint Slides This work is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International License. FIGURE 1.1 Biology is...

BIOLOGY 2e Chapter 1 THE STUDY OF LIFE Lecture PowerPoint Slides This work is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International License. FIGURE 1.1 Biology is the study of life, and so far, life is restricted to planet Earth. THE SCIENCE OF BIOLOGY Biology is the study of living organisms and their interactions with one another and their environments. Science can be defined as knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method The scientific method is a method of research with defined steps that include experiments and careful observation. Formerly called blue-green algae, these (a) cyanobacteria, shown here at 300x magnification under a light microscope, are some of Earth’s oldest life forms. These (b) stromatolites along the shores of Lake Thetis in Western Australia are ancient structures formed by the layering of cyanobacteria in shallow waters. (credit a: modification of work by NASA; credit b: modification of work by Ruth Ellison; scale-bar data from Matt Russell) Escherichia coli (E. coli) bacteria, seen in this scanning electron micrograph, are normal residents of our digestive tracts that aid in the absorption of vitamin K and other nutrients. However, virulent strains are sometimes responsible for disease outbreaks. (credit: Eric Erbe, digital colorization by Christopher Pooley, both of USDA, ARS, EMU) THE PROCESS OF SCIENCE The natural sciences include fields of science related to the physical world and its phenomena and processes. As such, science and biology are restricted to natural explanations of phenomena, not super-natural (god, magic, space aliens, etc.) explanations SCIENTIFIC REASONING Inductive reasoning is a form of logical thinking that uses related observations to arrive at a general conclusion. Deductive reasoning is a form of logical thinking that uses a general principle or law to forecast specific results SCIENTIFIC REASONING As is the case in this example, the conclusion from inductive reasoning can often become the premise for inductive reasoning. THE SCIENTIFIC METHOD The scientific method consists of a series of well-defined steps. If a hypothesis is not supported by experimental data, a new hypothesis can be proposed. BASIC VERSUS APPLIED SCIENCE Basic science or “pure” science seeks to expand knowledge regardless of the short-term application of that knowledge Applied science aims to use science to solve immediate problems (problems as defined by the researcher) PROCESS OF SCIENCE: PEER REVIEW Scientific progress is typically made through the publication of peer-reviewed literature. Peer review involves a blind process whereby scientists submit the details of their experiments, results and interpretations, and reviewers determine the veracity and merit of that work for publication. These papers typically follow a format of Abstract Introduction Methods Results Discussion Literature Cited FIGURE 1.8 After Hurricane Irma struck the Caribbean and Florida in 2017, thousands of baby squirrels like this one were thrown from their nests. Thanks to applied science, scientists knew how to rehabilitate the squirrel. (credit: audreyjm529, Flickr) PROPERTIES OF LIFE Order Sensitivity or response to stimuli Reproduction Growth and development Regulation Homeostasis Energy processing ORDER A toad represents a highly organized structure consisting of cells, tissues, organs, and organ systems. (credit: “Ivengo”/Wikimedia Commons) RESPONSE TO STIMULI The leaves of this sensitive plant (Mimosa pudica) will instantly droop and fold when touched. After a few minutes, the plant returns to normal. (credit: Alex Lomas)  RESPONSE TO STIMULI The photo shows a closeup image of a sunflower. https://www.youtube.com/watch?v=OfBsWFfWkGE&feature=youtu.be LEVELS OF ORGANIZATION Atoms Molecules Macromolecules Organelles Cells Tissues Organs and organ systems Organisms, populations, and communities Ecosystems biosphere BIOLOGICAL LEVELS OF ORGANIZATION THE DIVERSITY OF LIFE This phylogenetic tree was constructed by microbiologist Carl Woese using data obtained from sequencing ribosomal RNA genes. The tree shows the separation of living organisms into three domains: Bacteria, Archaea, and Eukarya. Bacteria and Archaea are prokaryotes, single-celled organisms lacking intracellular organelles. (credit: Eric Gaba; NASA Astrobiology Institute)