Ecology Final Exam
Ecology Final Exam Bio 260
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This 13 page Study Guide was uploaded by Michaela Humby on Monday August 1, 2016. The Study Guide belongs to Bio 260 at University of Tennessee - Knoxville taught by Charles Price in Spring 2016. Since its upload, it has received 8 views. For similar materials see Ecology in Biology at University of Tennessee - Knoxville.
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Date Created: 08/01/16
Michaela Humby May 4, 2016 Final Exam Review (40 points) Ecology 260, Spring 2 Instructor: Chuck Price Chapter 1 Ecology is the scientific study of interactions between organisms and their environment. Population: A group of individuals of a species that are living and interacting in a particular area. Community: An association of populations of different species in the same area. Ecosystem: A community of organisms plus their physical environment. Landscape: Areas with substantial differences, typically including multiple ecosystems. Biosphere: all living organisms on Earth plus the environments in which they live. Evolution: Change in genetic characteristics of a population over time; Descent with modification—organisms gradually accumulate differences from their ancestors Adaptation: A characteristic that improves survival or reproduction. Natural selection: Individuals with certain adaptations tend to survive and reproduce at a higher rate than other individuals. Producer: use energy from an external source to produce their own food. Consumer: get energy by eating other organisms or their remains 1) What is a controlled experiment? a. Experimental groups are compared with a control group that lacks the factor being tested. 2) What is the scientific method (in 4 steps). a. Make observations b. Make hypothesis c. Evaluate via experiments d. Modify and conclusions Chapter 2 (pay attention to figure 2.19) Weather Current or short term conditions—temperature, precipitation, humidity, cloud cover. Climate Longterm description of weather, based on averages and variation measured over decades; includes daily and seasonal cycles, as well as yearly and decadal cycles. Conduction transfer of heat through Convection transfer of heat through air or water Sensible heat flux Energy transfer from warm air immediately above the surface to the cooler atmosphere by convection and conduction. Latent heat flux: Heat loss due to evaporation. Michaela Humby May 4, 2016 Subsidence: Air descends when it cools and forms a high pressure zone at about 30°N and 30°S Albedo Amount of solar radiation a surface reflects; lightcolored surfaces have highest albedo. (Deforestation increases albedo of the land surface: Less absorption of solar radiation and less heating) Evapotranspiration Water loss through transpiration by plants, plus evaporation from the soil; It transfers energy (as latent heat) and water into the atmosphere, thereby affecting air temperature and moisture. Intertropical convergence zone the zone of maximum solar radiation and atmospheric uplift. Salinity: Concentration of dissolved salts in water. 1) What creates the latitudinal gradient in temperature and thus the driving force for climate dynamics? a. The sun (solar radiation) 2) What are the three atmospheric circulation cells going from the equator to the poles, and what are their corresponding climatic zones? a. Hadley cells: Large scale circulation patterns resulting from uplift in the tropics. (Tropical zone) b. Polar cells: at the North and South Poles—cold air descends, creating high pressure zones with little precipitation (polar zone). c. Ferrell cells: exist at midlatitudes. (Temperate zone) 3) What is heat capacity (define) and how does it differ from land to water? a. Water has a higher heat capacity than land—it can absorb and store more energy without changing temperature. 4) Where does upwelling typically occur and how does it affect productivity? a. Upwelling occurs where prevailing winds blow parallel to a coastline. Surface water flows away from the coast and deeper, colder ocean water rises up to replace it. They bring nutrients from the deep sediments to the photic zone, where light penetrates and phytoplankton grow. b. This provides food for zooplankton and their consumers. c. These areas are the most productive in the open oceans. 5) What creates a rain shadow? a. When air masses meet mountain ranges, they are forced upward, cooling and releasing precipitation. b. North–south trending mountain ranges create a rain shadow effect: The windward slope facing the prevailing winds has high precipitation and lush vegetation; the leeward slope gets little precipitation. 6) What are the layers in a stratified lake and what influences their turnover (slides 7981). Michaela Humby May 4, 2016 a. warm surface water on top of colder, denser water results in layers that do not mix. b. Stratification determines the movement of nutrients and oxygen; both are important to organisms. c. In summer, the warm epilimnion lies over the colder hypolimnion. The thermocline is the zone of transition. a. Complete mixing (turnover) occurs in spring and fall when water temperature and density become uniform with depth 7) What are the three Milankovitch cycles and what global phenomena are they associated with? a. The glacial–interglacial cycles have been explained by regular changes in the shape of Earth’s orbit and the tilt of its axis—Milankovitch cycles. b. variation and resulting in climatic change c. *the glacial and interglacial 100,000 years Chapter 3 Biosphere is the zone of life on Earth. It lies between the lithosphere and the trophosphere. Lithosphere: Earth’s surface crust and upper mantle Troposphere: Earth’s surface crust and upper mantle Biome: are largescale terrestrial communities shaped by the physical environment, categorized by dominant plant forms and characteristics such as leaf deciduousness or succulence. Lotic: flowing water systems. Lentic: Lakes and still waters Phytoplankton: are photosynthetic, restricted to the upper layers through which light penetrates Zooplankton: are nonphotosynthetic protists and tiny animals Detritus 1) What is convergent evolution? a. When 2 different species evolve in a similar way to solve a similar problem 2) What two factors are predictive of biome distributions? a. Temperature and precipitation (graph) 3) Draw a climate diagram and label the indicative sections. 4) What biome type do we live in (here in East Tennessee)? a. Temperate deciduous forest Michaela Humby May 4, 2016 5) What are the benthic and hyporheic zones in a stream ecosystem? 6) What is the river continuum concept? As streams increase in size, detritus from riparian vegetation decreases and becomes less important as a food source; fine organic matter, algae, and macrophytes become more important. Feeding styles of organisms also change: from shredders that tear up and chew leaves, to collectors that collect fine particles from the water. 7) What are the pelagic, littoral and photic zones in a lake ecosystem? a. Pelagic zone: Open water; dominated by plankton (small and microscopic organisms suspended in the water). b. The littoral zone is near shore, where the photic zone reaches the bottom. Macrophytes occur in this zone. c. the upper layers through which light penetrates (photic zone). Chapter 4 Physiological ecology: adaptation of an organism's physiology to environmental conditions. Climate envelope is the range of conditions over which it occurs. Stress: environmental change results in decreased rates of physiological processes, lowering the potential for survival, growth, or reproduction. Ecotype: Populations with adaptations to unique environments; can eventually become separate species as populations diverge and become reproductively isolated. Ectotherm: Regulate body temperature through energy exchange with the external environment. Endotherm: Rely primarily on internal heat generation—mostly birds and mammals. 1) What two options do organisms have for coping with environmental variation? a. Tolerance and avoidance 2) In what two ways (slide 7) does the physical environment influence an organism’s ecological success? a. Availability of energy and resources—impacts growth and reproduction. b. Extreme conditions can exceed tolerance limits and impact survival. 3) What’s the difference between potential and actual distribution? a. The actual geographic distribution of a species is also related to other factors, such as dispersal ability, disturbances, and competition. 4) What is the difference between adaptation and acclimatization and what times scales are associated with each? Michaela Humby May 4, 2016 a. Acclimatization: Adjusting to stress through behavior or physiology. It is a shortterm, reversible process. b. Over time, natural selection can result in adaptation of a population to environmental stress. Individuals with traits that enable them to cope with stress are favored. These genetic traits become more frequent. 5) Draw and label the gains and losses of energy from and leaf and stem (slide 23). 6) How does leaf hairiness influence leaf temperature? a. pubescence—hairs on leaf surfaces that reflect solar energy. But hairs also reduce conductive heat loss. 7) How does the relationship between surface area and temperature in an idealized sphere, demonstrate how body size influences heat loss? a. More large mammals in colder climates because they’re losing less heat due to lower ratio b. A smaller surface area relative to volume decreases the animal’s ability to gain or lose heat; As body size increases, surface areatovolume ratio decreases, and large ectotherms are improbable. 8) What four energy potentials are associated with water flow (slide 48)? a. Osmotic b. Matric c. Gravity d. Pressure 9) What is the relationship between average annual precipitation and the root to shoot ratio? a. A higher ratio of root biomass to stems and leaves enhances the rate of water supply. Chapter 5 Autotroph: Assimilate energy from sunlight (photosynthesis) or from inorganic compounds (chemosynthesis). Heterotroph: Obtain their energy by consuming organic compounds from other organisms. This energy originated with organic compounds synthesized by autotrophs. Photosynthesis: Sunlight provides the energy to take up CO and synthesize organic 2 compounds (most autotrophs). Chemosynthesis (chemolithotrophy): Energy from inorganic compounds is used to produce carbohydrates. Michaela Humby May 4, 2016 1) What is the range of wavelengths (minmax) over which chlorophylls absorb energy and where (approximately) are the peaks? 2) What is the net reaction of photosynthesis? 6 CO 2 H OC2H O 6 O6 12 6 2 3) Draw and label a light response curve (e.g. slide 27). 4) What pore allows plants to regulate water loss on short time scales? Stomates 5) What are the three main photosynthetic pathways found in plants? a. C ,3C 4 and CAM b. C 4hotosynthetic pathway reduces photorespiration and evolved independently several times. c. CAM minimizes water loss. 6) How does CO con2entration influence photorespiration? Photorespiration increases as CO c2ncentration decreases and temperature increases. Chapter 6 Heritable: able to be inherited (meaning a trait is able to be passed on from parent to offspring) Allele: Genes can have two or more forms called alleles; One allele is inherited from the mother, one from the father. Genotype is the genetic makeup of an individual. Evolution: is change in allele frequencies (proportions) in a population over time Natural selection: Individuals with certain heritable traits survive and reproduce more successfully than other individuals. Recombination: also produces different genotypes within a population; Offspring have combinations of alleles that differ from those of their parents. Fixation: Natural selection can result in populations in which all individuals have the favored allele the allele frequency for this trait is 100%(fixation) Genetic drift: occurs when chance events determine which alleles are passed to the next generation Gene flow: Alleles move between populations via movement of individuals or gametes; Gene flow has two effects:1. Populations become more similar. 2. New alleles can be introduced into a population. Michaela Humby May 4, 2016 Adaptation: features of organisms that improve their ability to survive and reproduce. Speciation: The process by which one species splits into two or more species. Evolutionary tree: is a branching diagram that represents the evolutionary history of a group 1) Phenotype a. =genotype+ environment b. Observable characteristics that are determined by the genotype, the environment, and interactions between the two. 2) What four factors can cause mutations (slide 20)? a. copying errors during cell division b. mechanical damage c. exposure to chemicals (mutagens) d. highenergy radiation 3) What are the four effects of genetic drift on small populations? 1. It acts by chance alone, thus causing allele frequencies to fluctuate at random. Some may disappear, others may reach 100% frequency 2. Because some alleles are lost, genetic variation of the population is reduced. 3. Frequency of harmful alleles can increase if the alleles have only mildly deleterious effects. 4. Differences between populations can increase. Chance events may lead to allele fixation in one population and loss from another population. 4) Draw a figure illustrating the three types of natural selection and their effects on the frequency of some idealized trait. 5) What is the biological species concept? Group of organisms whose members have similar characteristics and can interbreed. Chapter 7 Life history: is a record of events relating to its growth, development, reproduction, and survival. Fitness: genetic contribution to future generations Phenotypic plasticity: One genotype produces different phenotypes under different environmental conditions Allometry: Different body parts grow at different rates, resulting in differences in shape or proportion Isogamy: Gametes are equal in size. Anisogamy: Gametes of different sizes. Usually the egg is much larger and contains nutritional material. Michaela Humby May 4, 2016 Metamorphosis: Abrupt transition in form between the larval and juvenile stages. Semelparous: species reproduced only once Iteroparous reproduce several times within their lifetime. Niche: the physical and biological conditions that an organism needs to grow, survive, and reproduce. 1) What are the advantages and disadvantages of sexual reproduction? Disadvantages An individual transmits only half of its genome to the next generation. Population growth rate is only half that of asexually reproducing species. Recombination and chromosome assortment during meiosis can break up favorable gene combinations. Advantages of sexual reproduction: Recombination promotes genetic variation and increased ability of populations to respond to environmental challenges. 2) What is a complex life cycle? The stages have different body forms and live in different habitats and eat different foods; have at least two stages. 3) What is alternation of generations in a plant? Plants and most algae have alternation of generations where a multicellular diploid sporophyte alternates with a multicellular haploid gametophyte. 4) Draw the rselection, Kselection continuum and the traits and types of species associated with each end of the continuum. 5) What is a dimensionless number? Ratios allow comparisons of very different life histories; ex: average age maturity (time)/ average life span (time) cancel out the dimension (time) to get a dimensionless ratio 6) What is an example of the sizenumber tradeoff in plants? Small seeds, spores, eggs, and embryos are best suited to dormancy—less metabolic energy is needed to stay alive. Dispersal can reduce competition among close relatives and allow colonization of new areas Chapter 8 Sexual selection: Individuals with certain characteristics gain an advantage over others of the same sex solely with respect to mating success. Mating system: number of mating partners and patterns of parental care. Monogamy: one male one female Michaela Humby May 4, 2016 Polygyny: one male with many females Polyandry: one female with many males Promiscuity: both males and females mate with multiple partners. 1) What is optimal foraging theory and what does it maximize or minimize? Animals will maximize the amount of energy gained per unit of feeding time, and minimize the risks involved. 2) What is the profitability of a food item? a. Goal is to spend as little energy as possible to get the food with the most energy. Is it worth the energy or time to get a certain food item? 3) What is the handicap hypothesis? a male that can support a costly and unwieldy ornament is likely to be a vigorous individual whose overall genetic quality is high. 4) What is the sexy son hypothesis? the female receives indirect genetic benefits through her sons, who will themselves be attractive to females and produce many grandchildren. 5) What are some of the costs and benefits of group living (three each)? Benefits: Higher reproductive success; sharing responsibilities for caring for young; reduced risk of predation. Costs: Bigger group can lead to depletion of food; competition; spread of parasites or disease is easier 6) What is the dilution effect? a. As the number of individuals in a group increases, the chance of being the one attacked by a predator decreases. b. Group members may respond to a predator by scattering in different directions, making it difficult for the predator to select a target. Chapter 9 Distribution: geographic area where individuals of a species occur Abundance: number of individuals in a given area. Population: group of interacting individuals of the same species living in a particular area. Population size: number of individuals Population density: number of individuals per unit area Genet: a genetic individual from a single fertilization event Ramet: an actually or potentially independent member of a genet that may compete with other members for resources Geographic range: the entire geographic region over which a species is found 1) What are the three main types of spatial dispersion patterns and the processes that cause them? a. Regular individuals are evenly spaced b. Random individuals scattered randomly c. Clumped the most common pattern 2) Which spatial dispersion pattern is most common? Michaela Humby May 4, 2016 clumped 3) What is a markrecapture study used to estimate? a. Used for mobile organisms. b. A subset of individuals is captured and marked or tagged, then released. c. At a later date, individuals are captured again, and the ratio of marked to unmarked individuals is used to estimate population size. Chapter 10 Population growth rate: Ratio of population size in a year t+1 to population size in a year t Geometric growth : This predicts the size of the population after any number of discrete time periods. Geometric growth (discrete time): Exponential growth: This predicts the size of an exponentially growing population at any time t. Exponential growth at time t: change in population size at each instant in time Logistic growth: Population increases rapidly, then stabilizes at the carrying capacity (maximum population size that can be supported indefinitely by the environment). Ecological footprint: Total area of productive ecosystem required to support a population. 1) What is a life table and what is it used for? is a summary of how survival and reproductive rates vary with age. 2) What is the difference between a cohort life table and a static life table? a. Cohort life table: follows the fate of a group of individuals all born at the same time b. Static life table: Survival and reproduction of individuals of different ages during a single time period. 3) Draw the three types of survivorship curves (with axes labelled). 4) What does the age structure of a population influence? a. Proportion of the population in different age classes. b. Age structure influences how fast a population will grow. 5) Draw three graphs showing how r and λ influence population growth (slide 26) 6) What are densityindependent and density dependent factors? Densitydependent factors: Birth, death, and dispersal rates change as the density of the population changes. Densityindependent factors: Effects on birth and death rates are independent of the number of individuals in the population. (Like weather, food, temperature…) Chapter 11 Define the following terms (for the italicized terms I want the mathematical definition) Logistic equation with a time lag: N (t )population size at time t –τ in the past Michaela Humby May 4, 2016 Demographic stochasticity: chance events affect survival and reproduction of individuals. Environmental stochasticity: Unpredictable changes in the environment that can cause extinction of small populations. Metapopulation: A set of spatially isolated populations linked by dispersal of individuals or gametes. Extinction and colonization of patches (aka metapopulation growth): For a metapopulation to persist for a long time, e/c (extinction/colonization) must be <1. Rescue effect: High rates of immigration that protect a population from extinction. 1) What is delayed density dependence? a. Delays in the effect that density has on population size. b. Commonly, the number of individuals born in a given time period is influenced by population densities that were present several time periods ago. 2) What are the three types of curves observed with delayed density dependence (slide 22)? 3) What is the Allee effect? a. Growth rate decreases as population density decreases. b. At low densities, individuals have difficulty finding mates, so λ decreases. c. Allee effects can reduce small population size even further. 4) How does habitat fragmentation influence metapopulations? a. Large tracts of habitat are converted to isolated patches, resulting in a metapopulation structure. b. As patches get smaller and more isolated, colonization decreases and extinction rate increases. c. How does patch size and distance from other patches influence the probability of being colonized? Chapter 12 Competition: occurs between individuals of two species that share the use of a resource that limits their growth, survival, or reproduction. Resource: Features of the environment required for growth, survival, or reproduction, and that can be consumed to the point of depletion. Exploitation competition: Species compete indirectly; individuals reduce the availability of a resource as they use it. Interference competition: Species compete directly for access to a resource. Michaela Humby May 4, 2016 Amensalism: individuals of one species are harmed while individuals of the other species are not affected at all. LotkaVolterra competition equation measures population dynamics 1) Which is more intense, interspecific or intraspecific competition? 2) Name four examples of resources? Food, water, space, light 3) What is the competitive exclusion principle? Two species that use a limiting resource in the same way cannot coexist indefinitely. 4) What is resource partitioning? Species using a limited resource in different ways 5) What do the competition coefficients in the LotkaVolterra competition model describe? N 1= population density of species 1 r = intrinsic rate of increase of species 1 1 K 1= carrying capacity of species 1 α and β = competition coefficients—constants that describe the effect of one species on the other 6) What is character displacement? Natural selection can influence the morphology of competing species and result in character displacement. The phenotypes of competing species become more different over time. Chapter 13 Herbivore eats tissue of living plants or algae Predator kills or eats other organisms Parasite lives in or on another organism and feeds on parts of it Parasitoid: insects that lay eggs on or in another insect host. After hatching larvae remain in the host, which they eat and usually kill Crypsis: The prey is camouflaged, or resembles its background. Mimicry: The prey resembles another organism that is toxic or very fierce. LotkaVolterra predatorprey: When P = 0, the prey population grows exponentially.With predators present (P ≠ 0), the rate of prey capture depends on how frequently they encounter each other (NP) and efficiency of prey capture (a).The overall rate of prey removal is aNP. 1) What is a sit and wait predator? Predators that remain in one place and attack prey that move within striking distance 2) What are three physical adaptations to avoid being eaten? a. Large size (elephants) b. Rapid movement (gazelles) Michaela Humby May 4, 2016 c. Body armor 3) What are three behavioral adaptations to avoid being eaten? a. Not foraging in open areas b. Keeping lookouts (meerkats) c. Defensive circles (e.g., musk oxen Chapter 14 Symbiont: Organisms that live in or on other organisms; More than half of Earth’s species are symbionts; Our own bodies can be a home to many other species. Pathogen: are parasites that cause diseases; usually have a higher reproductive rate than their hosts. Macroparasites: Large species such as arthropods and worms. Microparasites: Microscopic, such as bacteria. Ectoparasites live on the outer body surface of the host. Endoparasites live inside their hosts, within cells or tissues or in the alimentary canal. Dynamics and spread of diseases: I increases when the disease is transmitted successfully and decreases when infected individuals die or recover. Death and recovery rate = m. 1) What are some of the advantages and disadvantages of living in or on a host (Table 14.1). Ectoparasites can disperse more easily than endoparasites; are more exposed to predators, parasites, and parasitoids. Endoparasites have evolved various mechanisms for dispersal, including complex life cycles and enslavement of hosts; are protected from the external environment and have easy access to food, but they can be attacked by the host’s immune system. 2) What is a threshold density? A simple model shows that a disease will spread only if the density of susceptible hosts exceeds a critical threshold density. 3) How can public health measures influence the density of susceptible individuals? a. Increase recovery rate (m) of infected individuals, who then have immunity, by early detection and improved treatment. b. Decrease transmission (β) by quarantining infected individuals or changing behaviors.
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