BIOL 152 1st Edition Exam 2 Study Guide Evidence of Evolution 1 Fossil Record Documents evolution of new taxa The order of appearance of organisms reflects their evolutionary relationships Intermediate transitional forms linking groups Archaropteryx links birds and dinosaurs 2 Example of how fossils allow tracing of character evolution Mammalian middle ear ossicles Quadrate incus anvil Articular malleus hammer Diffusion 1 In general as cells get larger surface area to volume ratio DECREASES Why is this significant Diffusion is better over small distances 2 Diffusion fundamental process of substance transport in biological systems Moves gases wastes nutrients etc into out of between and within cells Diffusion is a slow process where efficient transport of substances are limited to distance Bacteria and Archaea 1 Fill in the Cladogram this is a 3 branched tree of life based on sequence comparisons of the genes for the small subunit of ribosomal RNA Archaea and bacteria form distinct branches although they inherited prokaryotic cell organization from a common ancestor Eukarya Archaea Bacteria What do the tick marks represent left tick mark prokaryotic cell organization right tick mark eukaryotic cell organization 2 Properties of Organisms Obtain food Exchange gases Maintain proper water and solute balance Removes wastes reproduce 3 Bacteria Characteristics Nuclear membrane is present absent Organelles are present absent circular chromosomes Small Large cells Cell wall yes or no Gram positive bacteria vs Gram negative bacteria What is the difference between Gram negative and Gram positive bacteria and what is the difference in the arrangement of their layers Gram positive will stain the outside is just a layer of peptidoglycan and then an inner plasma membrane Gram negative won t stain b c it has an outer layer of carbohydrate portion of lipopolysaccharide and then as you go in its an outer membrane a peptidoglycan layer and an inner plasma membrane Peptidoglycan is absent in archaea 4 Archaea Characteristics Some are extremophiles o What are extremophiles Archaea that live in extreme environments like acid mines Nuclear membrane is present absent Organelles are present absent circular chromosomes Small Large cells Cell wall yes or no Peptidoglycan is present in bacteria and absent in archaea 5 How does Bacteria and Archaea reproduce Asexual Binary fission short generation times 20mins 24hours The prokaryote replicates its genes and divides into 2 daughter cells 3 methods of horizontal gene transfer o Bacterial Conjugation DNA in a plasmid goes from a donor cell and is transferred through a pilus into the recipient cell o Bacterial transformation one cell dies DNA is released into the environment and another cell comes by and takes it up o Bacterial transduction DNA is transferred via a virus 6 Biogeochemical cycles What is the significance carbon cycle sulfur cycle nitrogen cycle The evolution of cyanobacteria resulted in accumulation of oxygen in the atmosphere about 2 4 bya short term carbon cycle it s a back and forth bw photosynthesis and respiration primary producers are major players in carbon cycle microbial mat has a top layer of photosynthetic cyanobacteria 7 Name define and give an example of the different metabolic strategies that organisms use to obtain energy Photoautotrophs they get their energy from the sunlight and carbon from organic molecule aka CO2 Plants algae and cyanobacteria are photoautotrophs Chemoautotrophs they get their energy AND carbon from organic molecules taken up from the environment chemos use their surroundings to get inorganic molecules but don t use light Animals fungi and lots of prokaryotes Photoheterotrophs they get their energy from sunlight to make ATP like plants but rather than making their organic molecules they rely on the environment Bacteria and Archaea Chemoheterotrophs they cant make their own organic molecules aka carbon they have to ingest them Ex bacteria fungi and protozoa anoxygenic photosynthesis these type of organisms are photosynthetic that harvest light energy to drive the synthesis of carbohydrates but they don t make oxygen in the process Anoxygenic bacteria absorb sunlight using bacteriocholorophyll a pigment similar to cholorophylll It also employs only a single photosystem so it uses electron donors rather than water These type of organisms are restricted to sunlit habitats where oxygen is present aerobic respiration occurs in the presence of oxygen CO2 and water is produced Creates 38 ATP anaerobic respiration occurs without oxygen lactic acid alcohol is produced only creates 2 ATP 8 Species Co evolution The intimate physical relationship between two organisms in which at least one of the two species is dependent on the other is called symbiosis Name define and give an example of each type o Commensalism one benefits the other isn t harmed o parasitism one benefits at the expense of the other o mutualism beneficial to both organisms flashlight fish EUKARYOTES 1 Refer to the cladogram on pg 1 In the cladogram eukaryotic cell organization evolved after prokaryotic cell organization How is this possible BE SPECIFIC include hypotheses and evidence From comparisons of RNA molecules endosymbiotic origin of mitochondria and chloroplasts evidence they have their own circular genome cell wall molecules photosynthetic pigments phylogenetic evidence 2 Eukaryotic cell organelles function Endomembrane system synthesis of proteins transports o Nuclear envelope it surrounds the nucleus with a membrane with pores that regulate the passage of proteins RNA o ER transport proteins gatekeepers move molecules from one place to another o Golgi body sorting and packaging proteins o Lysosome break down waste Mitochondria powerhouse metabolic energy Chloroplasts photosynthesis Cytoskeleton support 3 Multicellularity Simple vs complex Simple Multicellularity o Cell adhesion cells attach to each other and cell matrix o Little cell to cell communication o Little differentiation o Typically all functions performed by all cells Complex Multicellularity o Cell adhesion Explain o Cell cell communication Explain o Cell differentiation Explain division of labor Which organisms have complex multicellularity humans 4 Protista Characteristics plant and fungal eukaryotes Not a monophyletic taxon Mostly unicellular Photoautotrophs mixotrophs heterotrophs Each cell is specialized to perform all life functions 5 Opisthokonts o animals o fungi o