Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
112 Cards in this Set
- Front
- Back
|
Energy |
All organisms acquire and use energy |
|
|
Cells |
All organisms are made up of membrane bound cells |
|
|
Information |
All organisms process hereditary information encoded in genes |
|
|
Replication |
All organisms are capable of reproduction |
|
|
Evolution |
Populations of organisms are continuously evolving |
|
|
Theory |
-Extremely well substantiated explanation; repeatedly tested and confirmed -An explanation for a general class of phenomena or observations -Cannot be proved |
|
|
Cell Theory |
-1600s -Robert Hooke: pore-like compartments are cells from cork -Anton van Leeuwenhoek: single celled "animalcules" in pond water -Conclusion: all organisms are made of cells; all cells come from preexisting cells |
|
|
Louis Pasteur |
-Do cells arise spontaneously? -All cells from cells vs. Spontaneous generation |
|
|
Theory of Evolution by Natural Selection |
-1858 -Charles Darwin and Alfred Russell Wallace -"Descent with Modification": All species are related by common ancestry; Species change over time through natural selection |
|
|
Evolution |
Change in heritable characteristics of a population over time |
|
|
Population |
Multiple individuals of a species living and breeding in the same area |
|
|
Natural Selection Conditions |
-Individuals must vary in characteristics that are heritable -Certain heritable characteristics help individuals survive better or reproduce more |
|
|
Pepper Moths in England |
-Before Industrial Revolution: 98% white, 2% black -During Industrial Revolution: 5% white, 95% black -After Industrial Revolution: white more common again |
|
|
Darwin's Finches |
-1970s -Peter and Rosemary Grant study finches Daphne Islet -Drought caused less production of seeds -Finch population declines |
|
|
Artificial Selection |
-Individuals with particular traits selected by humans -Repeating over generations: alters traits in a population |
|
|
Fitness |
Ability to produce fertile offspring |
|
|
Adaptation |
Trait that increases fitness |
|
|
Does evolution always result in species that are "better"? |
No |
|
|
Do individuals change when natural selection occurs? |
No |
|
|
Are individuals with high levels of fitness stronger or bigger or "more dominant"? |
Not necessarily |
|
|
Speciation |
Process of species splitting into two |
|
|
Tree of Life |
Describes genealogical relationships among all species |
|
|
Phylogeny |
-Shows genealogical relationships among organisms -Constructed by analyzing similarities and differences in traits |
|
|
Taxonomy |
Science of Classifying organisms |
|
|
Phylogenetic Tree |
A graphical representation of evolutionary relationships |
|
|
Linnaean Taxonomy |
-Carl von Linne (Carolus Linnaeus) (1707-1778) -Created system for classifying organisms -1. Each organism has unique two-part scientific name (genus and species) -2. Nested System of higher categories |
|
|
System of Higher Categories |
Kingdom --> Phylum --> Class --> Order --> Family --> Genus --> Species Kings Play Chess On Fine Grain Sand |
|
|
Kingdoms |
-Linnaeus: 2 Kingdoms: Plants, Animals -1960s: 5 Kingdoms: Plants, Fungi, Animals, Protista, Monera |
|
|
Carl Woese |
-1977 -Studied small subunit rRNA -proposed new taxonomic level called the Domain |
|
|
Ribonucleotides |
-A, U, C, G -rRNA is comprised of ribonucleotides |
|
|
Domain |
-3 Domains: Bacteria, Archaea, Eukarya -Include several related Kingdoms |
|
|
Chemical Evolution |
-Most cells are 96% Hydrogen, Carbon, Nitrogen, and Oxygen |
|
|
Ancient Atmosphere |
-Dominated by H2O, CO2, CO, N2 -No free O2 |
|
|
Two Models (Hypotheses) |
-Prebiotic Soup -Surface Metabolism |
|
|
Prebiotic Soup Hypothesis |
-Precursor organic molecules synthesized from simple molecules -Gases: CO2, N2, CO, H2, H2O + light energy = simple organic molecules = heat |
|
|
Stanley Miller Experiment |
-1953 -Can complex organic compounds develop from the simple molecules present in earth's early atmosphere? -Product: simple organic molecules and amino acids, important precursors for complex organic molecule needed for life |
|
|
Surface Metabolism Hypothesis |
-Dissolved gases accumulate on minerals in deep sea vents to form organic molecules -Need a mechanism to increase concentration -Minerals on wall of deep sea vents will concentrate same dissolved gases -Provides energy and catalyst for reactions |
|
|
Four Steps in Chemical Evolution |
-1. Production of simple organic molecules -2. Creation of more complex organic molecules (amino acids, etc.) via prebiotic soup and/or surface metabolism hypotheses -3. Link organic subunits to make larger molecules -4. Evolution of a self-replicating molecule |
|
|
Plato |
Typological thinking |
|
|
Aristotle |
"The Great Chain of Being" |
|
|
Curvier |
Described extinct mastodons/mammoths |
|
|
Lamarck |
-Evolution, but still believed in the chain of being -Mechanism: evolution of acquired traits |
|
|
Darwinian Evolution |
Mechanism: natural selection |
|
|
Natural (and Artificial) Selection |
-Driven by Fitness and Adaptation |
|
|
Fitness |
Ability to produce fertile offspring |
|
|
Adaptation |
Trait that increases fitness in a given environment |
|
|
Geological Uniformitarianism |
-Charles Lyell: 1830 "Principles of Geology" -Thomas Malthus: people may produce more offspring than can survive |
|
|
Natural Selection |
Acts on individuals |
|
|
Evolution |
Acts on populations |
|
|
Caveats |
-Variation exists naturally; organisms do not develop variation because they need a certain trait -Adaptations favorable at some times may be unfavorable at others -Evolution has no goal |
|
|
Evidence of Natural Selection |
-1. Some species go extinct -2. Transitional forms exist -3. Vestigal Traits: reduced structure with little/no function -4. Homologies: similar feature inherited from common ancestor: Structural, Developmental, Genetic -5. Similar species geographically |
|
|
Phylogeny |
Evolutionary history of a group of organisms |
|
|
Phylogenetic Tree |
Graphical representation of evolutionary relationships among species |
|
|
Branch |
Population through time |
|
|
Node |
Point at which two lineages diverge |
|
|
Tip |
(Terminal Node) Represents a group (species of larger taxon) living today or is extinct |
|
|
Polytomy |
Node with more than 2 branches -Usually result of incomplete information |
|
|
Ancestral Traits |
Older, "basal", existed in ancestor and all descendants |
|
|
Derived Traits |
More recent trait, found in group of interest, but not in last common ancestor |
|
|
Cladistics |
Focus on shared, derived traits of focal taxa |
|
|
Parsimony |
The most likely explanation requires the least amount of evolutionary change |
|
|
Plesiomorphy |
Ancestral Trait, shared by multiple taxa |
|
|
Synapomorphy |
Shared derived traits; found in most recent common ancestor and descendants |
|
|
Homoplasy |
Similar traits in different taxa that arose independently; not shared derived trait |
|
|
Homology |
Similar trait due to common ancestry |
|
|
Monophyletic Group |
Taxa that includes common ancestor and all descendants |
|
|
Outgroup |
Group that diverged before focal group |
|
|
Polyphyletic Group |
Group that includes more than common ancestor and descendants |
|
|
Paraphyletic Group |
Group that includes common ancestor but not all of its descendants |
|
|
How to Build Phylogenies |
-Choose species/groups of interest -Select characters (morphological, genetic, behavioral, etc.) -Choose outgroup -Populate data matrix (traits x species) -Build tree |
|
|
How do we Study the History of Life? |
-Fossils -Fossil Records |
|
|
Fossils |
Physical evidence of long dead organisms |
|
|
Fossil Record |
Sum total of all fossils ever found and collected |
|
|
How are Fossils Formed? |
-Organism is buried in sediments before decomposition -Burying allows mineralization, protection, slows decay |
|
|
Limitations of Fossil Record |
-Habitat Bias -Taxonomic/Tissue Bias -Temporal Bias -Abundance Bias |
|
|
Life's Timeline |
-4.6 GYA: Earth Forms -3.4 GYA: First evidence of life -2.5 GYA: First cyanobacteria -542 MYA: Cambian explosion - Time until 542 MYA: Precambrian |
|
|
Precambrian |
-New body plans appear suddenly -Hypotheses: -1. Oxygen -2. Evolution of predation -3. New niches create more niches -4. New Hox genes (genes that control development) |
|
|
Phanerozoic Era |
542 MYA- Present |
|
|
Big 5 Mass Extinctions |
-Ordovician -Devonian -Permian -Triassic -Cretaceous |
|
|
Permian Extinction |
~250 MYA -90% of species went extinct -Proposed Causes: -1. Volcanism -2. High CO2= global warming -3. Anoxic/Acidic oceans -4. Lowered sea levels= loss of shallow habitats -5. Low O2= land animals restricted to low elevations |
|
|
Cretaceous-Paleogene (K-P) |
-Extinction of Dinosaurs -65 MYA -Proposed cause: impact of massive asteroid (10km diameter) |
|
|
Adaptive Radiations |
-Lineage diversifies rapidly -Usually occurs when niches become available: On Islands, after mass extinctions, after morphological, new resources, new ways to exploit them |
|
|
Prokaryotes |
-Bacteria and Archaea -No nucleus -Diverse, abundant, and ubiquitous |
|
|
Prokaryotic Cell |
-Lack a membrane bound nucleus -All are haploid (single copy of each chromosome) |
|
|
Prokaryotic vs. Eukaryotic Cell |
-Nucleus (contains chromosome) -Similarities: DNA, Ribosomes, Plasma membrane, Cytoplasm |
|
|
Similarities between Bacteria and Archaea |
-Prokaryotes -Size (small; 0-20 micrometers) -Circular haploid chromosome -Rotating flagella (but different mechanisms) -no RNA processing |
|
|
Diversification of Prokaryotes |
-First appeared in fossil record 3.5 MYA -Types of Diversity: Morphological, Reproductive, Metabolic, Habitats |
|
|
Fission |
Cell split into two daughter cells (all bacteria and archaea) |
|
|
Conjugation |
Lateral transfer of genetic material between cells |
|
|
Conjugation Tube |
Mode of transfer unique to bacteria and archaea |
|
|
Cellular Respiration |
A molecule with high potential energy (electron donor) + a molecule with low potential energy (electron acceptor) = By-products + ATP |
|
|
ATP |
Energy currency of cells |
|
|
Aerobic Respiration |
Sugar + O2 = CO2 + H2O + ATP -Sugar: high potential electron donor -O2: low potential electron acceptor |
|
|
Photosynthesis |
CO2 + H2O + light = Sugar + O2 |
|
|
Electron Transport and Cellular Respiration |
Sugar (energy source) --> Oxygen (ATP) |
|
|
Life Requires |
-Source of Energy -Source of Carbon (for complex organic molecules) |
|
|
Sources of Energy |
-Light (phototrophs) -Organic molecules (sugars) (Chemoorganotrophs) -Inorganic molecules (ammonia, sulfate) (Chemolithotrophs) |
|
|
Phototrophs |
Oxygenic vs. Anoxygenic |
|
|
Oxygenic |
-Reverse of respiration -CO2 + H2O + light = sugar + O2 |
|
|
Anoxygenic |
-Something other than H2O donates electrons -Product is something other than O2 |
|
|
Sources of Carbon |
-Self-synthesized using simple molecules (usually CO2 or Methane) (Autotrophs) -From molecules made by others (Heterotrophs) |
|
|
Extremophiles |
-Soil -Oceans -Anoxic mudflats -Deepest parts of the oceans - Hot Springs -Hydrothermal vents -Hypersaline environments -pH as low as 1 -Under ice at 0 C |
|
|
The Oxygen Revolution |
No free molecular oxygen existed for the first 2.3 billion years of earth's history |
|
|
Nitrogen Fixation |
-Nitrogen is required for amino acids and other organic molecule -Nitrogen is abundant in atmosphere (~80%), but N2 is not usable -Some bacteria and archaea can "fix" N2 to nitrogen containing molecules used by plants/algae |
|
|
Nitrogen Cycle |
-Nitrogen fixing bacteria can be associated with plants- often taking up residence in nodules |
|
|
Bacteria and Human |
-Medical -Antibiotics -Symbiosis |
|
|
Medical |
A small fraction cause disease (pathogenic) |
|
|
Antibiotics |
-Compounds that help kill bacteria -Usually disrupt some essential cellular function (usually cell wall construction or protein synthesis) -Antibiotic resistance increasing -Antibiotics create strong selection for antibiotic resistance |
|
|
Antibacterial |
-Kill 99.9% of germs |
|
|
Symbiosis |
The human microbiome |
|
|
Bioremediation |
-The use of bacteria and archaea to degrade pollutants: -1. Fertilizing contaminated sites to encourage the growth of existing bacteria that degrade toxic compounds -2. Adding specific species of bacteria to contaminated sites |
|
|
Viruses |
-Contain genetic information (DNA or RNA) -Have a protein coat -Can evolve and reproduce -Do not have cellular structure -Do not have their own metabolism |
