BIOL 152 1st EditionExam # 2 Study Guide Lectures: 7-12Lecture 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 offspringPrezygotic - prevent mating or fertilization- Habitat isolation- Temporal isolation- Behavioral isolation- Mechanical isolation- Gametic isolationPostzygotic - 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 generationsSpecies 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 genetics2 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 hybridizationSympatric 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 offspringAdaptive 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 levelLecture 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 TaxonomyBinomial nomenclature - genus and specific epithet (ex: Panthera pardus = Leopard)- Latin, universal, avoid ambiguityHierarchical 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 donethrough:- Series of dichotomous branches- Deeper branch points represent greater amount of divergenceCladisticsCladogram - 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:- Eukaryote- Archaic- Bacteria IsomersStructural 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 directlyacross from each other- When diagonally opposite to the double bonds they are transFunctional GroupsParts 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 lifeo Hydroxylo Aminoo Carboxyl o Carbonylo Sulfhydrylo Phosphate o Methyl- Functional groups give organic properties distinctive chemical propertiesFour types of macromolecules:- Carbohydrates, lipids, proteins, nucleic acidsMonosaccharaides- Are the simplest of all sugars- Can be combined into polymers- May be linear- Can form ringsDisaccharides- Joined by glycosidic linkagePolysaccharides- Are polymers of sugars- Serve many roles in organisms such as o Storageo Structure- Cellulose is produced in plants - Chitin is produced in animals and fungiLecture 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 - straightFour 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 landCauses of Cambrian explosion?- predator prey relationship - increase in oxygen- hox gene complex aroseMesozoic:- coral reefs formed and provided new niches- reptiles dominated the seas and land- small nocturnal mammals appeared- birds began to appear during this timeCenozoic:- was followed after mass extinction- during this time period major radiation of flowering plants and insects appeared- large, mammalian herbivores, and carnivores appearedWhat are the animal characteristics:1.