Welcome To Biology 100 Instructor Gavan M. Albright, MS.

Biology Etology –Bi = Life –Ology = Study (of) Term coined circa 1800

Life Difficult to define Properties of living things –Cellular organization Precise structural organization at all levels –Metabolism Ability to take in and use energy –Homeostasis maintenance of stable internal environment –Capacity for growth and reproduction –Heredity DNA based genetic system

Cells All organisms composed of cells. Lowest level which exhibits “Life.” Single cell organisms are more general. Cells multicellular organisms have increased degree of specificity.

DNA Deoxyribonucleic Acid. Chemical blueprint for all other molecules. –4 different info molecules = Nucleotides. –Specific bases pair up (chemical bonding). Info carried in the sequence of base pairs. Sequence similarity is measure of evolutionary relatedness.

Biology’s Basic Core Themes 1) Evolution –Descent with modification Slow, subtle changes modify species over time –Natural selection Some individuals more “fit” than others More likely to pass on genes than others 2) Structure = Function –Change the structure, change the function Hemoglobin & sickle cell anemia Birds beaks specialized for what they eat

Biology’s Basic Core Themes 3) Connectedness (cooperation) –Living things have degrees of relatedness Basis for hierarchical classification –All Eukaryotes have nuclei –Plants & animals both have nuclei & similar organelles –All vertebrates have backbones –Web of connections between organisms & environ. All things affect other things –Cooperation, coevolution, predation, etc. Flow of energy through the environment –Energy ultimately comes from the sun (or heat) –Energy is processed from one trophic level to the next

Biology’s Basic Core Themes 4) Organization (hierarchical) –3 Primary Domains Bacteria = Prokaryotes (Single celled, anucleate) Archaea = Prokaryotes –Single celled, but evolutionary differences from bacteria Eukaria = Eukaryotes (true nucleus) –Protista = Algae & protozoans –Plantae = Plants –Fungi = fungus, yeasts, molds, mushrooms, etc. –Animalia = animals

Levels of Organization Biochemical Cellular Tissue Organ Organ System Organism Population Community Ecosystem

Science Method for understanding the world around us. Scientific Method –Observations –Questions –Hypothesis –Predictions –Tests –Results

Theory Scientific Theories –Ideas of which we are most certain All data to date support them But… still have the possibility of being proved wrong 4 Unifying Biological Theories –Cell theory –Gene theory –Theory of heredity –Theory of EVOLUTION