Essentials of Biology Sylvia S Mader Chapter 1 Lecture Outline Prepared by Dr Stephen Ebbs Southern Illinois University Carbondale 1 1 The Unity and Diversity of Life The living organisms on our planet show tremendous diversity in form and function Despite this diversity all organisms share certain characteristics that distinguish them from non living things The similarity in these characteristics provides evidence that all organisms descended or evolved from a common ancestor Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Living things are organized into levels of biological organization Levels of biological organization The cell is the most basic unit of life Similar cells together form tissues Similar tissues together form organs Organs work together in organ systems Organ systems form complex organisms Complex organisms together form higher levels of organization Living things acquire materials and energy The chemical reactions that occur in cells are a part of metabolism Some reactions extract nutrients building materials and energy from food Photosynthesis involves chemical reactions that use solar energy to form chemical energy For metabolism to continue in cells all chemical reactions must be kept in a balance called homeostasis Living things respond reproduce and develop Organisms interact with and respond to their environment often with movement Every type of living organism can reproduce produce another organism like itself Unicellular organisms reproduce by cell division Multicellular organisms use sexual reproduction 1 Living things respond reproduce and develop cont Living things have adaptations Adaptations are modifications that make a particular type of organism i e a species suited to its way of life Species become modified over time by natural selection which preserves genetic changes that make them better suited for their environment Evolution is descent with modification driven by the process of natural selection 1 2 How the Biosphere is Organized 1 2 How the Biosphere is Organized cont The biosphere includes the land sea and air and all organisms on Earth Individuals of the same species belong to a population The populations of species in a given area are the community The interaction of communities with the environment forms an ecosystem 1 3 How Organisms Are Classified Because living things are diverse taxonomy was created to group organisms into categories and to understand their evolutionary relationships Domain Kingdom Phylum Class Order Family Genus Species Most inclusive There are three domains of living organisms The Domains Archaea and Bacteria are both comprised of prokaryotic bacteria Archaea bacteria live in extreme environments Anoxic no oxygen High salinity High temperature Least inclusive 2 There are three domains of living organisms cont The four kingdoms of Eukarya Domain Eukarya consists of all nonbacterial organisms Eukarya is divided into four kingdoms Protista Fungi Plantae Animalia Organisms within kingdoms are given scientific names Unique scientific names are used to identify and classify organisms The scientific name is called the binomial name and consists of a genus and species Peas Genus Pisum species sativa Humans Genus Homo species sapiens The scientific method The naming of living organisms has revealed the biodiversity of the Earth Biodiversity is the sum total of all organisms and their genetic information 15 million organisms are believed to exist on the Earth 400 species per day are lost to extinction Conservation biology includes efforts to protect biodiversity and ecosystems Experiments performed in science have specific elements The experimental design is the well conceived plan for a specific experiment Experiments typically have two groups Experimental group the group manipulated during the experiment Control group the reference group left unmanipulated Experiments collect data 3 Science and society The application of science for a practical purpose is called technology Science is impartial and does not make ethical or moral judgments The role of society is to use scientific information to make informed decisions about the use of technology 4