BIOL 152 1st Edition Exam 2 Study Guide Lectures 7 12 Lecture 7 February 11 What is reproductive isolation What are the two aspects of reproductive isolation and its examples Reproductive Isolation are biological factors that impede members of two species from producing viable fertile offspring Prezygotic prevent mating or fertilization Habitat isolation Temporal isolation Behavioral isolation Mechanical isolation Gametic isolation Postzygotic prevent viable fertile hybrids Reduced hybrid viability can reproduce some hybrids Reduced hybrid fertility can t reproduce hybrids Hybrid breakdown can t reproduce after many generations Species concept Morphological species concept are characterized by body shape size and structure Ecological species concept are characterized by species niche interactions with living and nonliving environment Phylogenetic species concept are characterized by their phylogeny on the animal lineage and genetics 2 types of speciation Allopatric speciation gene flow is reduced by physical barrier Population separated in space Allopatric speciation is much more common in animals Gene flow prevents allopatric speciation Secondary contact takes place and only then will it lead to hybridization Sympatric speciation gene flow is reduced by reproductive barrier Populations in same place but separated through small barriers More common in plants Polyploidy can lead to speciation Autopolyploidly having an extra set of chromosomes when reproduced from the same species Allolpolyploidy when hybrids develop gametes that reproduce to make new species Concepts Hybridization concept of species being separated by geographic barriers and their way of coming back together to reproduce viable offspring Reinforcement occurs when the hybrid offspring are selected against and the barrier between the species strengthens Fusion occurs when the two species come together and reproduce many viable hybrid offspring but leads to loss of divergent individuals Geographic or other biological barriers are weakened Stability occurs when both species survive and can also reproduce to make viable hybrid offspring Adaptive radiation Is the rapid evolution of many diverse species from a common ancestor upon introduction to new environmental opportunities Cambrian Explosion lead to adaptive radiation 2 types of evolution Microevolution how gene frequencies change in a population Macroevolution the cumulative effects of speciation over vast amounts of time is evolutionary change above the species level Lecture 8 February 13 Why fossils are important 90 of species that ever existed are extinct Reveal ancestral characteristics Substantial but incomplete Biased toward abundant species that dominated regions widespread and shows a display of only bony structures Taxonomy Binomial nomenclature genus and specific epithet ex Panthera pardus Leopard Latin universal avoid ambiguity Hierarchical classification species are grouped into increasingly broad inclusive categories Taxonomic unit at any level is called a taxon For example domain kingdom etc Phylogenetic trees branching of diagrams that depict hypotheses about evolutionary relationships done through Series of dichotomous branches Deeper branch points represent greater amount of divergence Cladistics Cladogram depicts patterns of shared derived characteristics Present in one population but not in ancestral populations Monophyletic is a valid clade branches off one ancestor and shows many of its descendants Paraphyletic contains only some of descendants of its group Polypyletic grouping organisms that don t share a common ancestor Principle of parsimony the theory that the simplest explanation is the best solution aka Occam s Razor Lecture 9 February 18 What are the 3 domains Isomers Eukaryote Archaic Bacteria Structural isomers are those arranged differently but consist of the same molecular form Cis and Trans Cis occurs when an element that is attached to a two carbon chain with a double bond is directly across from each other When diagonally opposite to the double bonds they are trans Functional Groups Parts of molecules involved in that are involved in a chemical reaction Chemically reactive groups of atoms within an organic molecule There are seven functional groups that are important in the chemistry of life o o o o o o o Hydroxyl Amino Carboxyl Carbonyl Sulfhydryl Phosphate Methyl Functional groups give organic properties distinctive chemical properties Four types of macromolecules Carbohydrates lipids proteins nucleic acids Monosaccharaides Are the simplest of all sugars Can be combined into polymers May be linear Can form rings Disaccharides Joined by glycosidic linkage Polysaccharides Are polymers of sugars Serve many roles in organisms such as o Storage o Structure Cellulose is produced in plants Chitin is produced in animals and fungi Lecture 10 February 20 Macromolecules and polymers Starch and Glycogen Starch stored in plants as amylose and amylopectin Glycogen stored in animals in the liver Starch 1 4 linkage of alpha sheet structure is known as helices Cellulose 1 4 linkage of beta sheets structure is known as straight Four levels of protein structure Primary structure Unique sequence of amino acids in a polypeptide chain Secondary structure Consists of chains coiling H bonds within polypeptide backbone Consists of alpha and beta sheets Tertiary structure 3D shape Amino acid chain interacts with side chains Van der Waals interactions Ionic bonds Disulfide bridge H bonds with side chains Quaternary structure Has an overall protein structure Consists of two or more polypeptide subunits Lecture 11 February 25 Geologic time period Paleozoic fishes dominated the marine environment insects and plants colonized land amphibians appeared then reptiles appeared on land Causes of Cambrian explosion predator prey relationship increase in oxygen hox gene complex arose Mesozoic coral reefs formed and provided new niches reptiles dominated the seas and land small nocturnal mammals appeared birds began to appear during this time Cenozoic was followed after mass extinction during this time period major radiation of flowering plants and insects appeared large mammalian herbivores and carnivores appeared What are the animal characteristics 1 Heterotrophs have to consume food 2 Multicellular 3 No cell walls 4 Specialized cells only found in animals muscle and nerve 5 Most reproduce sexually 6 Diploid form dominated the life cycle 7 Regulatory genes hox