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115 Cards in this Set
- Front
- Back
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What are some characteristic features of living things that distinguish them from non-living things?
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- Reproduction
- Metabolic energy transfer - Membranes in cells - They respond to the environment - Information content, DNA & RNA |
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How old is the earth?
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4.6 Billion years old.
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What is the general nature of early life evidence, and their order of appearance?
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3.8 BYA Evidence from molecular studies shows early life hot and chemotrophic.
3.8 BYA Geological evidence from organic deposits in earliest sedimentary rock. 3.5 BYA Possible fossil bacteria with organic inclusions 3.2 BYA Filamentous microfossils 3.0 - 2.7 BYA Developed bacterial communities, photosynthesizers that built stromatolites. |
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How has the biosphere affected Earth's physical environment and where did 02 and 03 come from?
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The early atmosphere was CO2. Cyanobacteria, a microbe, producing O2 as a by-product of photosynthesis, gave us the oxygen rich environment of today. Respiration and photosynthesis drive the carbon exchange today. O3 is found in the atmosphere and forms when lightning hits oxygen atoms.
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Why did the early Earth have high levels of ultraviolet (UV) radiation, and what caused these levels to decline?
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Lack of an atmosphere. Levels started to decline as the oxygen levels rose.
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What biological processes are involved in releasing carbon to the atmosphere? What kinds of organisms are involved?
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Respiration and decomposition. All animals are involved in this process.
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What other process besides respiration and decomposition releases carbon from the biosphere to the atmosphere? How are humans changing this process?
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Burning wood, fossil fuels. Humans are changing this by reducing the amount used for daily life.
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What is a stromatolite and how do stromatolites provide clues to ancient forms of life?
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Rocklike structure composed of layers of prokaryotes and sediment.
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What is “net primary production” (NPP)? What organisms are responsible for NPP?
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NPP is gross primary production minus the energy used for respiration by the GPP producers.
Photosynthesizers are the producers. |
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Be familiar with basic nutrient cycling and energy flow diagrams (schematics, or “models”) found in your textbook.
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See photo.
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Carbon cycling.
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Carbon Cycle
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Nitrogen Cycle
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Nitrogen.
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Phosphorus Life Cycle
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Phosphorus
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Is the concept of “global warming” pure speculation, or is there solid scientific evidence for global warming? In what latitudes does the atmospheric [CO2] change the most, from seaon to season? In what latitudes is there little change? Why?
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There is solid evidence in the "hole" in the atmosphere over antarctica. Also, monitoring stations in places such as Mauna Kea provide evidence of heightened O2 levels in the atmosphere.
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Ecology
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The study of interactions between organisms and their environment.
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Ecosystem
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The entire community of organisms plus all the abiotic factors that exist in a certain area.
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Biogeochemistry
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A branch of geochemistry that is concerned with biologic materials and their relation to earth chemicals in an area; the science studying changes in the earth's chemical constituents as mediated by living organisms (eg, bacteria).
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What are the different hypotheses regarding the origin of life?
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1) Primordial soup - ( such as Miller and Ulrey, who demonstrated that many molecules can develop in an anoxic environment. This ended the concept of vitalism, and produced the field of early-life studies and the search for extremophiles.
2) RNA world - cech and altman. Scientists usually think everything comes from DNA, they were trying to show everything comes from RNA. 3) Panspermia - idea that life started from molecules brought to earth on space rocks. |
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What types of compounds were formed in the experiments of Miller and Urey?
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Amino acids.
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What is a “protobiont” and what properties of living things would they possess?
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A protobiont is a prototype of life, membrane-bound stores of chemical compounds that display some properties of life.
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What was found in ALH4001 (the “Mars meteorite”) studied by McKay and colleagues?
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Rocks from mars that contained possible fossils of bacteria-like microbes.
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Compare and contrast the 5-kingdom system to the 3-domain system of taxonomic classification. Which one is more phylogenetically accurate?
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5 Kingdom:
- emphasized difference between prokaryotes and eukaryotes. - lumped all eukaryotes that were not plants, fungi, or animals together under "protists" 3 Kingdom system: - phylogenetically correct - Emphasizes differences between 3 main groups, based on evolutionary history. - Three groups, Bacteria, Archaea, Eukarya. |
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Define prokaryotes and the organisms that they represent.
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Prokaryotes are comprised of Archaea and Eubacteria, or "true" bacteria. They are small, typically 1 - 5 microns, they have no nucleus or organelles, and they move with a flagellum. They have circular chromosomes w/ fewer genes than eukaryotes, and plasmids hold their DNA.
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Contrast different ways of classifying life (e.g. taxonomic approaches, phylogenetic approaches, associations of organisms according to physical factors, according to types of metabolism, etc.)
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1) Shape - They are round, rod-shaped, and spiral.
2) Cell Wall - Whether or not they are gram positive or gram negative. 3)phylogenetically - evolutionary relationships using DNA 4)Metabolically ( autotrophic, heterotrophic, nitrogen fixing) |
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Understand that the bacteria (eubacteria) and the archaebacteria (archaea) represent two fundamentally distinct clades.
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Eubacteria - Tend to grow in aerobic, less extreme environment.
Archaea - Genetically closer to eukaryotes than eubacteria. Initially were thought to be much older than they actually are, hence the term Archae. They are generally anaerobes and can be extremophiles. |
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Classification by Kingdom
1) Plantae 2) Fungi 3) Animalia 4) Protista 5) Monera Problems with: a) not all bacteria are alike b) not all protists are related |
Classification by domain:
1) Domain Bacteria 2) Domain Archaea 3) Domain Eukarya Emphasizes differences in 3 main groups based on phylogeny. |
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Understand-
a) Photo- b) Chemo- c) Auto- d) Hetero- |
a) Having to do with light.
b) Having to do with chemicals c) As in making your own d) As in needing something else to help you make it. |
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Bacteria are 10X smaller than typical eukaryotic cells. What are the major bacterial cell features?
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Eubacteria cell
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How do bacteria reproduce?
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They do not have sex per se. There is an exchange of DNA during conjugation through pili, which are hollow tubes connecting the two cells. This generates genetic diversity by trading plasmids, and portions of the chromosomes.
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What are the various biogeochemical roles of bacteria?
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A) Alpha Proteobacteria - Rhizobium, may be where mitochondria come from.
B) Beta Proteobacteria - aid in nitrogen cycling in soil. B)Gamma Proteobacteria - includes salmonella, e. coli. Sulfur bacteria. D) Epsilon Proteobacteria - Mostly pathogenic E) Chlamydia - Gram-negative pathogens. F) Spirochetes - Free living or pathogenic such as syphillis or lyme disease. G) Gram positive bacteria - Very diverse group has Actomycetes. which are chain forming like TB. Also solitary bacteria like anthrax, botulism, staph, and strep. |
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Streptomycetes
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Soil bacterium that is the source for most modern antibiotics.
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Contrast photosynthesis in sulfur bacteria to that in cyanobacteria.
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Cyanobactera --
CO2 + H2O -> CH2O + O2 Sulfur bacteria -- CO2 + H2S -> CH2O + S2 CH2O is the generic formula for sugar (=energy) Any molecule that has hydrogen attached to it is a potential energy source. Sulfur bacteria produce under anoxic conditions. |
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What distinguishs eubacteria from archaea (archaebacteria)?
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Eubacteria -
Oxygenic, bacteria we usually think of as pathogenic Archaea - Anaerobic, extremophiles, do not have peptidoglycan. They can be methanogens, extreme halophiles, or thermoacidophiles (hot water living. |
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What is the role of archaebacteria in digestion?
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They take oxidized carbon in the anoxic environment (cow rumen, termite hindgut) and convert is to reduced carbon which can then be used by the host as energy. Methane is given off as waste in the process.
4H2 + CO2 -> CH4 + 2H2O |
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What is the role of anaerobic bacteria in methanogenesis?
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Methanogenesis is a form of anaerobic respiration. It is the final step in the decay of matter. The archaea live off of the carbon and produce methane as by-product.
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What were Darwin’s 4 postulates to his hypothesis of evolution by natural selection? How were these postulates revised in the Modern Synthesis?
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Darwin’s theory had 4 postulates, or underlying assumptions:
(1) Individuals within a species are variable (2) Some of this variation is passed to offspring in other words, traits are heritable) 3) In every generation, more offspring are produced than can survive (due to limited resources) (4) Survival and reproduction are not random: |
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How do natural selection and sexual selection affect a population? In what way are they similar? Different?
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Natural selection affects a population by causing evolution that results in adaptation, producing organisms that are better suited for their particular environment.
Sexual selection affects population by generating variation among offspring, creating new allele combinations not present in either parent. They are different in that natural selection makes a population more adapted to its environment, sexual selection does not- it makes one sex more successful at mating with the other. |
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What’s the difference between intra- and inter-sexual selection?
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Inter-sexual selection - males appeal to female preferences.
Intra-sexual selection - males compete with each other for access to females. |
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Wallace observed that habitats like islands that were isolated for long periods of time had many endemic species. What does endemic mean? Why does isolation plus time equal new species?
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Endemic means exclusively native to a place or biota. Isolation + time = new specoies because the place was first populated by action of winds and currents....the original species die out, and the modified prototypes remain.
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Why doesn’t Intelligent Design fall into the category of science?
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Because it is not testable empirically.
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Evolution
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All the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today.
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Alleles
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Alternative versions of a gene that produce distinguishable phenotypic effects.
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Reproductive Isolation
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The existence of biological factors (barriers) that impede members of two species from producing viable, fertile hybrids.
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Gene Flow
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Genetic additions to or substractions from a population resulting from the movement of fertile individuals or gametes
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Phylogeny
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A hypothesis of how organisms are related to each other by descent from a common ancestor.
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Synapomorphy
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A shared, derived characteristic.
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Monophyletic group
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A group that includes all descendants of an ancestor.
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What is the difference between a homologous structure versus an example of homoplasy? Give an example of each. What produces homoplasy, and how does it affect systematics (the science of naming things and grouping them correctly)?
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A homologous structure is structurally similar, but functionally different, than another. Example is the human arm, dolphin flipper, and bat wing.
Homoplasy is a trait that makes us think two organisms are related when in fact they are just similar due to convergent evolution. Example is bird and bat wings. |
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How does cladistics reconstruct the evolutionary relationships among modern organisms? In other words, what be might the basis for grouping certain organisms together in a class, family, or genus?
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Groups used to be named because they were morphologically distinctive, such as birds and cetaceans. This did not reflect their evolutionary status. Clades only use monophyletic groups. Examples include birds and reptiles as vertebrates.
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Compare the Biological Species Concept and the Phylogenetic Species concept
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Biological species concept says that species are defined as groups of actually or potentially interbreeding individuals. Phylogenetic species concept states instead of depending on reproductive isolation, it revolves around fixed differences between populations. Rationale is to be called separate species 2 populations must have been evolutionarily independent so long that they have become recognizably different.
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What has to happen for one population to diverge and produce two distinct species?
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1) Gene flow is reduced or interrupted
2) Populations diverge, mating preferences change 3) Reproductive isolation arises 4) Speciation ultimately results (they can't make babies) |
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Provide a basic definition of protists. Understand why protozoans are not a monophyletic (natural) group
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Protists are a diverse group of eukaryotes, including many unrelated lineages.
Plant-like (Photosynthetic) - Algae Animal-like ( motile, heterotrophic) Fungal-like (heterotrophic) They are also metabolically diverse, being autotrophic, heterotrophic, or both. Morphologically they are simple. They have no true tissues. Simple def - Very simple eukaryotes that lack tissue. They are not a monophyletic group because they have no phylogenetic validity, and they exclude 3 groups of descendants. |
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Understand the history (evolution) of metabolism and how it relates to bacteria and eukaryotes; be familiar with the basic processes of photosynthesis vs. respiration
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Mitochondria are responsible for aerobic respiration in almost all eukaryotes including plants. In a heterotrophic process, they extract maximum energy from organic compounds by using 02 as the final acceptor for electrons.
CH2O + O2 -> CO2 + H20 <- this milks all the energy out of electrons Chloroplasts - organelle that is series of stacked membranes called thylakoids, which contain pigment chlorophyll. They drive carbon fixation converting CO2 into organic, high-energy compounds (sugars.) |
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Be able to compare and contrast bacterial (e.g. cyanobacteria) and eukaryotic cells (e.g. green algae). How are they similar? How are they different?
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Cyanobacteria - small, simple cells with peptidoglycan, circular chromosome, no membrane bound organelles, small ribosomes, are anaerobic or aerobic, and have sexual reproduction via conjugation.
Eukaryotes are large complex cells, with no cell wall, nucleus contains many linear chromosomes, membrane-bound organelles (nucleus, plastids), large ribosomes, aerobic, sexual reproduction through meiosis. |
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What is the Endosymbiotic Theory, and the difference betwene primary and secondary endosymbiosis; what is the evidence for each?
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Lynn Margulis championed the Endosymbiotic Hypothesis, which held that eukaryotic mitochondria and chloroplasts were originally prokaryotes
- first expanded on this idea in 1981; was treated like a heretic Suggested: (a) mitochondria were descended from an aerobic bacterium (b) chloroplasts from a phytosynthetic cyanobacterium An ancient, anaerobic eukaryote engulfed an aerobic eubacterium Aerobic respiration yields way more ATP (= cellular energy) than less efficient anaerobic respiration Instead of eating this engulfed cell, they struck up a partnership, or symbiosis - bacterium got a safe place to live, and a steady supply of carbon compounds, - eukaryote got a more efficient form of metabolism, lots of extra ATP |
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Understand importance of phytoplankton and macroalgae to food webs in the ocean, especially important examples like the giant kelp, Macrocystis sp.
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Open ocean dominated by microscopic phytoplankton, single-celled photosynthesizers that fix CO2, they form the basis of the food web, they are eaten by little critters, which are eaten by fish, which are eaten my humans....Shallow water dominated by macroalgae w/ large, multicellular bodies
- giant kelp Macrocystis pyrifera, sea lettuce Ulva lactuca which is critical as food for near shore animals. |
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Understand that many of the protozoa are parasitic, and be familiar with some major protozoan diseases and the organisms that cause them
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Protozoans are parasitic, which is to say they feed off of another host and benefit, while the host loses out by having disease....
Phylum Kinetoplastida (Trypanosomes) - Cause African Sleeping sickness, leishmaniasis, and chagas' disease. Phylum Plasmodium (Malaria) causes malaria Diplomonadida (e.g. Giardia lamblia - giardia) |
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Understand features that make protists effective parasites.
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- complex life cycles with several hosts (e.g. Plasmodium sp. or Pfiesteria sp.)
- life cycles that combine asexual reproduction (for making many copies of yourself) and sexual reproduction (for generating new diversity) - ability to change surface proteins (e.g. Trypanosomes) to avoid detection by the host immune system |
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What is the role of certain protists (Diatoms, Foraminiferans) in forming marine sediments, and why this is important to the carbon cycle, and studying past climates
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Diatoms skeletons accumulate in the ocean depths, where calcium carbonate dissolves, creates layers of siliceous ooze. Foraminiferans tests (shells) are abundant in marine sediment, and they are excellent markers for correlating the ages of sedimentary rock.
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How do how amoeba engulf prey, move by pseudopods, and regulate their water balance?
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They engulf prey by phagocytosis, where food particles are surrounded by vesicles, and then intracellular digestion takes place. They move by extending pseudopods, which are extensions of their cytoplasm. They regulate water through the use of contractile vacuoles, which fill with excess water and then excrete it to the outside of the cell.
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What are the effects of Dinoflagellates on human health and ecosystems?
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They cause red tides, which use up all the 02 in an area, leading to mass kills of life. Also, produce potent toxins which fish eat, and then humans eat and get sick by. Example is saxitoxin ( Paralytic shell fish)
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Phylum Chytridiomycota
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Chytrids - aquatic parasites or saprobes. They are a primitive representation of the fungal kingdom.
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Phylum Zygomycota
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Zygomycetes - About 600 species of them, 100 of these live as endomychorrizae with plants. Zygomycetes have zygosporangia, which produce zygospores.
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Phylum Ascomycota
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Ascomycetes - Over 30000 species to date. Yeast is an example of this. Ascomycetes have ascocarp which house asci that produce ascospores.
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Phylum Basidiomycota
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Basidiomycetes - terrestrial fungi, common mushroom belongs to these. Basidiomycetes have basidiocarp which house basidia whiich produce basidiospores.
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What are the key features distinguishing fungal groups (e.g. sexual reproductive structures)
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In zygomycetes, the hyphae of opposite mating types fuse to form heterokaryotic (N+N) structure, which is the zoosporangium. This contains many haploid nuclei from each parent. Conditions improve and karyogamy occurs, (haploid nuclei fuse). Zygote then undergoes meiosis, and then regular sporangia may form to produce spores by mitosis.
Ascomycetes - The "sac" fungi, produce sexual spores in sacklike asci, contained in the ascocarps, or fruiting body. They have an extended heterokaryotic stage which allows time to cross over to generate diversity. Penicillium is an example of an ascomycete. Also yeast. Basiomycetes - Also have a long lived heterokaryotic stage, which is where the mushroom comes up in bad conditions. |
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Saprobes
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Decomposers that absorb carbon compounds
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Mycorrhizae
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Mutualistic symbioses between fungi and plant roots. There are two kinds:
Endo- usually a zygomycete. Ecto- usually a basidiomycete |
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Lichens
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Mutualistic symbioses between fungi and either a green alga or a cyanobacterium.
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Heterokaryotic
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Referring to mycelium formed by the fusion of two hyphae that have genetically different nuclei.
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Dikaryotic
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Referring to a fungal mycelium with two haploid nuclei per cell, one from each parent
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Fungi are responsible for many diseases of plants and humans
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They destroy 10-50% of crops every year. Contributes to high rate of liver cancer in areas that consume peanut meal, which supports fungi that produce toxins.
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What is the economic importance of fungi?
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Used in the production of dough and grain products. Also in the production of beer. They are also very important for antibiotics.
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What are the ecological roles of fungi in decomposing organic material (carbon cycle), and making nutrients (e.g. nitrogen, phosphorus) available to plants?
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They are decomposers which break down complex organic molecules into simpler organic compounds. They can break down lignin which is found on wood, and cellulose (which animals can't break down)
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Define a “plant” In particular, know how plants differ from other photosynthetic organisms (photosynthetic protists, cyanobacteria)?
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Multicellular eukaryotes that carry out photosynthesis. They are generally photosynthetic autotrophs. Key differences between plants and other organisms are the presence in plants of a cuticle, multicellular gametangia, and non-motile spores.
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Do land plants share a common ancestor with green algae?
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Yes they do. This is evidenced by both having primary endosymbiosis, photosynthetic pigments, starch storage in plastids, production of cell walls from cellulose, cell plate formation during cell division, and the sporic life cycle.
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What are the four stages in land plant evolution, and know that
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Early land plants (~400 MYA) bryophytes and seedless vascular plants
Diversification (~390 MYA) abundance of seedless vascular plants Evolution of the seed (~ 300 MYA) Gymnosperms (naked-seeded plants) Evolution of flowers and fruits (~ 130 MYA) Angiosperms (flowering plants) Also know that: a) both bryophytes and seedless vascular plants arose in the first stage b) seedless vascular plants diversified and dominated the Earth in the second stage, during the Carboniferous Period (~350-300 MYA), when coal deposits were formed c) that gymnosperms dominated until the mass extinction that wiped out the dinosaurs |
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What are the major themes in land plant evolution, increasing their adaptation to dry terrestrial environments?
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a)Increasing adaptation to a terrestrial enviroment.
b)Progressive reduction of the gametophyte, increasing dominance of sporophyte. c)Increased protection d)Increased height, structural strength, and more complex tissues. |
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Moss Life Cycle
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Moss
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Fern Life Cycle
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Fern
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What are the differences between the features of bryophytes (e.g. moss) and seedless vascular plants (e.g. fern); how are their life cycles different?
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Bryophytes have dominant gametophyte stage, seedless vasculars have dominant sporophyte stage. Bryophytes lack vascular tissue, and seedless vasculars have it.
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Sori
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Clusters of sporangia on a fern sporophyll. Sori may be arranged in various patterns, such as parallel lines or dots, that are useful in fern identification.
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Strobilis
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The technical term for clusters of sporophylls known commonly as cones, found in most gymnosperms and some seedless vascular plants.
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Antheridium
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The male reproductive organ in algae, ferns, fungi, and mosses
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Archaegonium
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The female reproductive organ of mosses, ferns, liverworts, and most gymnosperms. It contains a single egg cell.
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Sporophyte
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In plants that alternate between sexual and asexual phases, a plant in its asexual spore-producing phase
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Gametophyte
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The phase in the life cycle of a plants in which sex organs and gametes are produced.
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Understand the following themes in plant evolution (be able to explain these themes and provide specific examples):
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a) Progressive reduction of gametophyte and dominance of sporophyte. Ex- In gymnosperm, gametophyte is big, in angiosperm, it is microscopic.
b) Greater protection of reproductive parts, the advent of the seed – replaces spores c) Advent of pollen (immature male gametophyte) – replaces swimming sperm d) Improved vascular tissues allowing growth to greater heights above ground |
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What are the four gymnosperm phyla, and know an example of each?
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Phylum Ginkogophyta - ginkobiloba tree
Phylum Cycadophyta - cycads Phylum Gnetophyta - Ephedra Phylum Coniferophyta - conifers |
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Angiosperm
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Angiosperm
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The pine life cycle.
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The pine life cycle.
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What adaptations enable conifers to survive in dry conditions?
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Tough needle-like leaves, dense leaf tissues, thick cuticles, recessed stomata
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Know that angiosperms replaced gymnosperms as the dominant land plant group around 65 million years ago at the end of the Mesozoic Era
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Know it.
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What are the key differences between angiosperms and gymnosperms?
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Flowers vs. cones, the naked seeds vs. seeds enclosed in fruit, improved transport tissues (e.g. xylem with vessel elements), and the increased dependence upon animals for pollination and dispersal in the angiosperms
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Understand the concepts of coevolution and symbiosis as they apply to angiosperms, animals, and fungi.
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In particular, know that many angiosperms have co-evolved with their animal pollinators and fruit dispersers, and be able to cite examples of pollination or dispersal syndromes. Example include the hummingbird and flower, fragrance and nighttime pollinators
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How do angiosperms protect themselves from competitors and from herbivores?
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With cuticle on leaves, sometimes producing toxins. Also, improved protection of their reproductive parts.
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How does coevolution contribute to biodiversity?
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Coevolution can promote species formation, particularly in organisms like specialized herbivores or parasites, that mate on or inside their host. Studies suggest that when angiosperms started speciating, beetles that fed on them also divided into distinct specialist populations
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Describe the parts of a flower.
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Flower
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Describe parts of a fruit.
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Fruit Development
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Seed Structure
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Seed Structure
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Understand the angiosperm life cycle; be able to explain double fertilization
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Angiosperm life cycle.
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What are the features distinguishing monocots from dicots?
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Monocots are a clade consisting of flowering plants that have one embryonic seed leaf, or cotyledon. Dicot is a term traditionally used to refer to flowering plants that have two embryonic seed leaves, or cotyledons. Recent molecular evidence indicates that dicots do not form a clade (see eudicots).
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Provide examples of heterotrophic (parasitic or carnivorous) angiosperms.
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Monotropa is a parasitic angiosperm, and the venus flytrap is a carnivorous angiosperm.
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Explain the economic and ecological importance of angiosperms, and the human uses for plant defensive chemicals.
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Important component of global photosynthesis (esp. tropical and temperate forests)
Form critical habitat for animals (including us) Our economy is dependent upon angiosperms (ecosystem functions) Sources of everyday products (e.g. hardwoods), medicinal drugs Source of our food (directly or indirectly) – over 80% of our food comes from six species: rice, soy, wheat, corn, sorghum, and millet |
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Pericarp
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The thickened wall of a fruit.
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Anther
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In an angiosperm, the terminal pollen sac of a stamen, where pollen grains with male gametes form.
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Stamen
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The pollen-producing reproductive organ of a flower, consisting of an anther and filament.
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Sepal
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A modified leaf in angiosperms that helps enclose and protect a flower bud before it opens.
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Tracheid
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A long, tapered water-conducting cell that is dead at maturity and is found in the xylem of all vascular plants.
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Vessel elements
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A short, wide, water-conducting cell found in the xylem of most angiosperms and a few nonflowering vascular plants. Dead at maturity, vessel elements are aligned end to end to form micropipes called vessels.
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Petal
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A modified leaf of a flowering plant. Petals are the often colorful parts of a flower that advertise it to insects and other pollinators.
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Flower
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In an angiosperm, a short stem with up to four sets of modified leaves, bearing structures that function in sexual reproduction.
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Fruit
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A mature ovary of a flower that protects dormant seeds and aids in their dispersal.
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Ovule
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A structure that develops within the ovary of a seed plant and contains the female gametophyte.
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Seed
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An adaptation for terrestrial plants consisting of an embryo packaged along with a store of food within a resistant coat.
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