Biology Study Guide
Biology Study Guide BIO 100
Popular in Intro to Biology
Popular in Biology
This 6 page Study Guide was uploaded by Asia Glenn on Tuesday February 23, 2016. The Study Guide belongs to BIO 100 at West Chester University of Pennsylvania taught by Jack Waber in Winter 2016. Since its upload, it has received 115 views. For similar materials see Intro to Biology in Biology at West Chester University of Pennsylvania.
Reviews for Biology Study Guide
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: 02/23/16
Evolution and Diversity Extant Life Forms and How They got Here Origin of Universe n Age =13.73 X 10 + 9.12 years n Big Bang at T0 Origin of the Solar System Origin of Earth I Origin of Earth II Origin of Earth III Darwin’s Theory of Evolution by Natural Selection n Any population of living organisms can evolve (change over time) when individuals in the population differ from one another in one or more inheritable traits that affect the ability of an organism to survive and reproduce. Gene Pools n Gene Pool = all of the genes for an entire population. n Each gene has two or more alleles; each individual inherits two particular alleles/gene. n Which alleles form the “pool” end up in a new individual depends on five unrelated events. n n Mutation: produces new alleles and ultimately provides the raw material for evolution n Crossing Over: new combination n Independent Assortment: mixes paternal and maternal chromosomes n Fertilization: produces new combinations. n Change in Chromosome Number or Structure: causes loss, or duplication, or repositioning of genes Natural Selection n Operates on a population with genetic diversity in traits that effect survival and reproduction. It affects the relative abundance (frequencies) of alleles that are responsible for adaptive and/or maladaptive phenotypes (traits) from generation. Modes of Selection Directional Selection Examples n Peppered Moths: Light to Dark n Pesticide Resistance: Chemical selection for resistant forms n Antibiotic Resistance: Selection for resistant pathogenic bacteria Unnatural Selection: Purebred Dogs SickelCell Anemia and Malaria Species and Speciation n Species = a population of individuals that share a common gene pool under natural conditions n Prevention of gene flow by geographical isolation and/or accumulation allelic differences over time leads to reproductive isolation and thus the creation of a new species. n In a evolutionary context, all extant species are related. Evolving from variant individuals of species that already existed starting with the first cells. Diversity and Classification n Systems of Classification attempt to impose a measure of order on the myriad life forms that have evolved in the last 3.5 Billion years. n System must be: Large and Inclusive, group together organisms that share characteristics, reveal evolutionary relationships. Hierarchical Classification n Kingdom n Phylum/Division n Class n Order n Family n Genus n species Origin of Life on Earth Origin of Life:Theories n Special Creation n Spontaneous Generation n Extraterrestrial Contamination Special Creation n Life on Earth is the direct result of divine intervention. n Several “Creation Legends”exist. n NOT a scientific theory that can be tested, but rather a “test of faith”. It is not science, but religion. Spontaneous Generation n Life can arise from nonliving materials in the grossest possible form. n Louis Pasteur disproved the 19th century notion of the theory with his famous “Swan necked Flask” Experiment. Pasteur’s Swan Necked Flask Experiment n Where no life previously exists, none will appear magically. n Disproves Spontaneous Generation. Spontaneous GenerationRevived n Pasteur: SG does not happen under current conditions. In fact, Life did arise from nonliving matter, but under very different conditions than exist today. Evolutionary process went through three distinct phases: Geological/Chemical/Biological 4.5 Billion Years Ago Earth Condenses from Rocks Dust and Gas and Stratification Occurs Chemical Evolution n Lighter Elements begin to form a “protoatmosphere”: H , CH ,NH ,H O and perhaps 2 4 3 2 other gases, but NO oxygen. n Energy Sources of drive chemical reactions:UV, Heat, Electrical Discharge n Prebiotic Synthesis of organic (carbon based compounds) occurs. UreyMiller Experiment Did UreyMiller Experiment “create” Life? n No. It did prove that it is possible to create an chemical environment could serve as the basis for the evolution of Life. n Possible to abiotically create a “primordial soup”. What is “Alive”? n Membrane n Metabolic System n Genetic System Membrane Formation n Oprin was the first to note that under controlled conditions, large macromolecules, proteins, lipids, ect., will spontaneously form Coacervate Droplets. These “droplets” could have served as the basis for a true Membrane. Evolution of Metabolic Pathways n Initially, everything provided by “soup”. n When critical element is in short supply, those that can synthesize it from simpler, more available chemicals have an advantage. n Thus metabolic chains grow increasingly longer and longer as surviving “organisms” become less dependent on abiotic synthesis. Evolution of Genetic Systems n Current System: DNA>RNA>Protein n 1980’s Tom Cech discovers that some RNA’s can act as enzymes. n Ribozymes could carry genetic information AND express it. Thus primordial world was probably an “RNA World”. n How current system evolved is under study. Extraterrestrial Contamination n Life on Earth is the result of “contamination” by some extraterrestrial organism. n Possible, but improbable and impossible to test. n Puts the origin of life off the planet. Initially, everything provided by “soup”. When critical element is in short supply, those that can synthesize it from simpler, more available chemicals have an advantage. Thus metabolic chains grow increasingly longer and longer as surviving “organisms” become less dependent on abiotic synthesis.
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'