Principles of Biology - BIO 111 Lecture Notes PDF

BIO 111  Principles of Biology The scientific study of life living things how life works What is life??? Principles of Biology I Course Learning Objectives (CLOs) The foundations of life 1.List and understand the characteristics shared by all l...

BIO 111  Principles of Biology The scientific study of life living things how life works What is life??? Principles of Biology I Course Learning Objectives (CLOs) The foundations of life 1.List and understand the characteristics shared by all living organisms that set them apart from nonliving things. 2.Name and describe the relationships between the levels of biological organization from the smallest scale to the largest. 3.List the macromolecules (and their general roles) of which all living organisms are made. 4.Describe the general features of cells and be able to distinguish between prokaryotes and eukaryotes. 5.Describe how we classify organisms and how phylogenetic trees show the evolutionary relationships between organisms. 6.Explain how evolution accounts for both the unity and diversity of life on Earth. CLO 1  CLO 1 An organism possesses/exhibits all of these characteristics by itself  CLO 1 An organism is a living whole that is greater than the sum of its parts  CLO 1 An organism is a living whole that is greater than the sum of its parts  CLO 1 An organism is a living whole that is greater than the sum of its parts  CLO 1 An organism is a living whole that is greater than the sum of its parts  CLO 1 An organism is a living whole that is greater than the sum of its parts  CLO 1 Biological systems are dynamic: Characterized by rapid flows of matter and energy. They constantly exchange energy and matter with their surroundings. Even though there is constant turnover of atoms, molecules, etc., the organization of the systems persist.  CLO 2 Biology Is Studied at Many Levels of Organization The study of life (biology) extends from the submicroscopic scale of molecules, to cells, and to the global scale of the entire living planet Many biologists study life at one level but gain a broader understanding when they integrate their discoveries with processes at other levels.  CLO 2 The hierarchy of life starts at the atomic level CLO 4 The cell is the basic unit of life  The Cell is the Basic Living Unit CLO 4 The cell is the lowest level of structure capable of performing all of the activities of life independently. All organisms are composed of cells. Cells may exist as independent, unicellular organisms or as subunits of multi-cellular organisms  CLO 4 Prokaryot es versus Eukaryot es  CLO 3 & 4 Life arose by chemical evolution. Molecules that could reproduce themselves were critical. Biological molecules were then enclosed in membranes. Biologically Important Macromolecules Nucleic Acids Proteins Lipids Carbohydrates ~ 4 billion years ago  The Continuity of Life is Based on Heritable Information in the Form of DNA CLO 3 Biological instructions for ordering the processes of life are encoded in DNA (deoxy- ribonucleic acid). DNA is the substance of genes, the units of inheritance that transmit information from parents to offspring.  The Continuity of Life is Based on Heritable Information in the Form of DNA CLO 3 All forms of life employ the same genetic code. The diversity of life is generated by different expressions of a common language for programming biological order. What is that common language? The sequence of nucleotide bases in DNA. The Continuity of Life is Based on Heritable Information in the Form of DNA CLO 3 Genome - the sum total of all the information encoded by an organism’s genes DNA - consists of repeating subunits called nucleotides. Gene - a specific segment of DNA that contains information for making a protein Proteins - govern chemical reactions in cells and form much of an organism’s structure.  The Central Dogma of Molecular Biology CLO 3 The central dogma of molecular biology describes the flow of genetic information in the cell  The Continuity of Life is Based on Heritable Information in the Form of DNA Cells contain chromosomes made partly of DNA, the substance of genes. DNA 1) Programs the production of proteins in the cell and 2) Is transmitted from parents to offspring during reproduction. Living organisms and systems are highly diverse CLO 5 CLO CLO 5  Unity in the Diversity of Life CLO 6 Underlying the diversity of life is a striking unity, especially at the lower levels of organization. This unity is evident in the following ways: a) A nearly universal genetic code b) Similar metabolic pathways c) Similarities of cell structure Evolution accounts for the combination of unity and diversity of life.  CLO 6 Evolution: a central, unifying theme of biology. Evolution is simply the change in the genetic makeup of biological populations through time. Living systems evolve through differential survival and reproduction  Natural selection Adaptatio The processes of evolution have n generated the enormous diversity of life on Earth.  CLO How is All Life on Earth Related? 6 According to modern evolutionary biology, all living beings are descendants of a unique ancestor. Evolution results in the separation of organisms into related groups, and ultimately into species. Species: The most basic and specific unit of classification consisting of similar individuals capable of exchanging genes or interbreeding, giving rise to offspring capable of reproducing. Taxonomic classification is a hierarchical system used to CLO 5 categorize organisms. The higher classifications are by domain and kingdom levels. The deepest and the most detailed classification is the genus and species levels.  Domain Eukarya Classifying Life CLO 5 Animalia Chordata Mammalia Primata Hominidae Learning Homo Objective 5 Homo sapiens  Phylogenetic Trees CLO 5 An evolutionary “tree” (phylogenetic tree) illustrates the order in which populations split and evolved into new species. Scientists study the evolution and classification of organisms using the fossil record and molecular evidence. 6 Kingdoms 3 Domains Phylogenetic Trees CLO 5  CLO 5 Scientists group species on an evolutionary tree (~3.7 Billion years ago) using information from physical structures, genetic similarities, and fossil records.  CLO 5 FIG. 1.15 Evolutionary relationships among primates.