Biology 102 Bio 102
Popular in Introduction to Biology
verified elite notetaker
Popular in Biology
This 7 page Class Notes was uploaded by Alyssa Shriver on Sunday January 24, 2016. The Class Notes belongs to Bio 102 at University of Tennessee - Knoxville taught by Dr. Jeremy Chandler in Spring 2016. Since its upload, it has received 173 views. For similar materials see Introduction to Biology in Biology at University of Tennessee - Knoxville.
Reviews for Biology 102
Yes YES!! Thank you for these. I'm such a bad notetaker :/ will definitely be looking forward to these
-Dr. Penelope Feest
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/24/16
1/14/16 Biology Introduction Biology the study of life Life’s hierarchy of organization define the scope of biology o Life emerges through organization of various levels o With addition of each new level, novel properties emerge called emergent properties 7 properties of life o Order o Regulation o Growth and development o Energy processing o Response to the environment o Reproduction o Evolution Levels of hierarchy o Biologists explore life at levels ranging from the biosphere to the molecules that make up cells The Upper Tier o Is a global perspective of life Biosphere all the environments on Earth that support life Ecosystem all the organisms living in a particular area Community the array of organisms living in a particular ecosystem Population all the individuals of a species within a specific area The Middle Tier o The middle tier is characterized by the organism, an individual living thing, which is composed of Organ systems have specific functions; are composed of organs Organs provide specific functions for the organism Tissues made of groups of similar cells The Lower Tier o Life emerges at the level of the cell, the lower tier, which is composed of Molecules clusters of atoms Organelles membranebound structures with specific functions Cells living entities distinguished from their environment by a membrane What is Science? o A way of knowing based on inquiry o Systematic study of the natural world and natural phenomena o Science developed from our curiosity about ourselves and the world around us o The word science is derived from a Latin verb meaning “to know” How do scientists draw conclusions? o Reports in the news; Coffee causes cancer Coffee prevents some diseases Caffeine can be poisonous o Use best evidence available o Ask: Was the science performed properly? o Conclusion may be modified in the future o Science is a neverending process Science is a process: make an observation o Start with an interesting informal observation o Often unreliable untested o Anecdotal evidence Science is a process: formulate a question o Use observation to devise a question Science is a process: studying previous research o Read relevant literature o See current information on the subject of interest o Study peerreviewed scientific literature Validity in science o Hypothesis driven science scientific method and logic are applied to support or refute a hypothesis A hypothesis is a tentative explanation made on the basis of evidence collected The strength of hypothesis driven science relies on the empirical nature of its investigation A hypothesis can never be “proven” only supported Science is a process: studying previous research o Peer review: review of an article by experts before publication o Ensures that the authors have appropriately designed and interpreted their study o Weeds out sloppy research Culture of Science o Scientists build on what has been learned from earlier research They pay close attention to contemporary scientists working on the same problem o Cooperation and competition characterize the scientific culture Scientists check the conclusions of others by attempting to repeat experiments Scientists are generally skeptics o Science has two key features that distinguish it from other forms of inquiry. Science.. Depends on observations and measurements that others can verify and Requires that ideas (hypotheses) are testable by experiments that others can repeat Two approaches to Science o Discovery science describe natural phenomena based on observations. Patterns and correlations lead to formation of a hypothesis o Hypothesis driven science scientific method and logic are applied to support or refute a hypothesis Example of discovery science o In 1929, Alexander Fleming discovered that Penicillium mold generated a substance that kills bacteria o In 1941, Howard Florey and Ernst Chain purified penicillin The first commercial antibiotic to save human lives Example of Hypothesis driven science o Criteria for establishing a causative link between an infectious agent and a disease Dr. Barry Marshall o Drank to fulfill Koch’s postulate that it was causative organism of some stomach lesions and ulcers Science is a process: forming scientific hypotheses o A hypothesis is never proven o If false, it is rejected and no longer considered a possible answer to the original question o If the data support the hypothesis, it will be accepted until further testing and data show otherwise Science is a process: experimentation o Experimental group: experiences the experimental intervention or manipulation o Control group: experiences no experimental intervention of manipulation Basis for comparison Science is a process: drawing conclusions o Sample size (n) is important o It is the number of experimental subjects of the number of times an experiments are repeated o The larger the sample size, the more likely the results will have statistical significance o Statistical significance is a measure of confidence that the results obtained are “real” rather than due to random chance Lecture 1/19/16 Selection and Adaptation Methicillinresistant Staphylococcus aureus (MRSA) o Infectious bacterium o Difficult to treat with antibiotics o Kills 19,000 people in the United States each year Staphylococcus aureus o S.aureus (also known as “staph) o Some strains are harmless, other cause disease o Drugresistant strains exist Methicillinresistant Staphylococcus aureus (MRSA) o Developed resistance to antibiotic drugs o Adversely affects people with weakened immune system o Rocky Lannetti was already weakened by the flu Healthy 21yearold football player o The young, whose immune systems are still developing, and the elderly are at especially high risk o People who are already sick and fighting off other infections can be at high risk too Antiobiotics o Chemicals that either kill bacteria or slow their growth o Interfere with function of essential bacterial cell structures Bacteria reproduce through a process called binary fission. Binary fission is a form of asexual reproduction in which a single parent cell replicates its contents and then divides into two daughter cells. o Each daughter cell inherits all its DNA from the single parent cell Antibiotic resistance o Bacteria emerge that survive antibiotics o Acquire random mutations when DNA replicates during asexual reproduction o Binary fission: one parental cell into two daughter cells o Acquisition of new alleles in bacteria may result in antibiotic resistance Random mutation Gene transfer Asexually reproducing bacterial populations become genetically diverse by accumulating mutations and by picking up genes from organisms of the same or different species Mutation o Mutations made during DNA replication introduce new alleles into the populations Gene transfer o DNA can pass from one bacterial species to another. A nonstaph bacterium, for example, can pass genes to staph and introduce genes into the staph population that confer new traits, such as antibiotic resistance How populations evolve o A population is a group of organisms of the same species living together in the same geographic area o An entire population can change (evolve) when some traits are favored over others o For example, a drugresistant trait o Genetically diverse population o Varying allele frequency o Environment favors some alleles over others o Allele frequency changes over time (called evolution) o Fitness: organisms ability to survive and reproduce in a particular environment o Higher fitness= increased likelihood of alleles being passed to next generation o Genes that confer resistance to antibiotics increase an organism’s fitness o Organism’s alleles, or genotype, determine phenotype o Interplay between phenotype and environment determine frequency of traits in a population o If traits improve fitness, traits become more common in population Phenotype o From Greek phainein, meaning “to show”, and typos, meaning “type” o An organism’s observable characteristics or traits, such as its morphology, development, biochemical or physiological properties, phenology, behavior, and products of behavior Genotype o An individual’s collection of genes or alleles (variant form of a gene) inherited from a set of parental genes How populations evolve o Organism’s alleles, or genotype, determine phenotype o Interplay between phenotype and environment determine frequency of traits in a population o If traits improve fitness, traits become more common in population o Population evolves o These processes all occur as a result of selection o Populations, not individuals, evolve o Populations experience changes in allele frequencies over time Mechanism of Evolution o Selection Artificial selection selective breeding for desired traits in an organism Natural selection process where organisms better adapted to their environment produce more offspring and In artificial selection humans are in effect the “environment” that selects In 1929, Alexander Fleming discovered that Penicillium mold generated a substance that kills bacteria In 1941, Howard Florey and Ernst Chain purified penicillin o The first commercial antibiotic to save human lives Natural selection: differential survival and reproduction of individuals within a population in response to environmental pressure Advantageous traits become more common and population becomes better suited, or adapted, to environment Natural selection occurs in patterns o Directional selection: predominant phenotype shifts in a particular direction o Stabilizing selection: phenotype of populations settles near middle of range Ex. Human babies with very low birth weights do not survive as well as larger babies, and very large human babies are not easily delivered through the birth canal. Midrange babies are favored o Diversify selection: phenotype of population is at both extremes of range Three General Outcomes of Natural Selection o Directional selection: shifts the overall makeup of a population by selecting in favor of one extreme phenotype o Stabilizing selection: favors intermediate phenotypes, occurs in relatively stable environments, and is the most common o Diversifying selection: can lead to a balance between two or more contrasting phenotypic forms in a population Evolution of the unseen microbial world o Antibiotic resistance in bacteria is a growing problem that threatens everyone’s way of life Why sudden rise in antibiotic resistance? o Several factors have contributed Availability and use Profitability $$$ Evolution! Antibiotic resistance is a growing problem worldwide o Antibiotics are overused o Overprescribed; used in farm animal feed This exerts selective pressure for drugresistant strains o Streptococcus pneumonia o Acinetobacter baumanii Resistant to multiple drugs Stopping superbugs o Control resistance by changing practices that enable resistant strains to thrive o Wash hands, use hand sanitizers, stop misuse of antibiotics
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'