Ecology Exam questions and Answers 100% guaranteed A.

Ecology Exam questions and Answers 100% guaranteed A. 8 ecological maxims 1. Organisms never do just one thing 2. Everything goes somewhere 3. No population can increase in size forever 4. There is no free lunch 5. Evolution matters 6. Time matters 7. Space matters 8. Life would be impossible without species interactions Real world applications: 5 ecosystem services(oxygen, filtration, goods) conservation human health(medicine) restoration sustainability(agriculture, fishing, etc) Population group of individuals of the same species that live within a particular area and interact with one another Community group of interacting species that occur together at the same place/time The biotic components of a specific location Ecosystem all organisms in a given area as well as the physical environment in which they live All biotic and abiotic components in an environment Biosphere All environments supporting life on Earth Total available area with living organisms Abiotic nonliving Biotic living Ecology scientific study of interactions between organisms and their environment Environment the surroundings or conditions in which an animal or plant lives or operates Ecological Niche abiotic & biotic conditions needed by a species to survive, grow, & reproduce Habitat physical environment Climate LONG TERM trends in meteorological variables Weather temp, rain, wind, etc of a place at a PARTICULAR TIME What climate variables are most important to distribution of terrestrial ecosystems? Temperature and precipitation sensible heat flux Heat loss from convection and conduction latent heat flux Heat loss from evaporation albedo? Ice, Snow, water Ability of a surface to reflect solar radiation Ice and snow have higher albedo, more reflected Greenhouse effect Concentration of gases in atmosphere influences temperature Scientific Research in Ecology Ecological research often has real-world applications Ecological research uses the same scientifc methods used in other sciences. What is the initial input of energy driving the global climate cycle? solar radiation T/F: Deforestation can cause changes in regional climate True Solar radiation cycle majority absorbed by earth surface, second most reflected, some absorbed by atmosphere water cycle? infiltration evaporation and evapotranspiration form condensation then precipitation, precipitation goes back to earth evapotranspiration( evaporation and transpiration) infiltration(water soaks in ground then makes its way to ocean) How does deforestation affect climate? increased albedo, lower solar absorption increased sensible heat loss reduced evapotranspiration, less precipitation essentially climate has less plants, almost desert like, colder, less rain General Trend: Higher biodiversity in ----- than --- or ----- tropical ecosystems temperate or polar ecosystems Most diverse ecosystem Tropical Rainforests Most diverse group of plants angiosperms Most diverse group of animals invertebrates Marine Ecosystems All water bodies with salinity more than 0.5 ppt Oceans cover --- of Earth's surface 75% Freshwater Ecosystems All water bodies with salinity of less than 0.5 ppt Freshwater ecosystems cover less than --- of Earth's surface --- of Global Biodiversity 1% 6% Terrestrial Ecosystems All ecosystems on land Freshwater Ecosystems: Lentic Systems Lotic Systems Still Flowing littoral zone- benthic zone- limnetic zone- euphotic zone- aphotic zone- shallow water by shore substrate bottom open water portion part where light reaches no sunlight Ecotone? Biodiversity level? transition zone between ecosystems High Permafrost? what effect does it have on soil conditions? Decomposition rate? frozen subsoil -Prevents soil drainage -Soils stay wet despite low precipitation Slow decomposition rate What effect does extreme conditions have on availability of resources? Biodiversity of ecosystem? Biodiversity in extreme ecosystems tends to be low • Limited to species w/ specialized adaptations • Less resources Which ecosystems has the highest and lowest biodiversity? Tropical Rainforest tundra Boreal Forest Evergreen, coniferous trees permafrost Tropical Rain Forest 50% of Biodiversity hot, humid, high rainfall, low soil nutrients due to high decomposition rates Tundra Extremely cold, low levels of light during fall/winter, low rainfall Permafrost Small shrubs, grasses, mosses, lichens(no trees) Animals have adaptations to extreme cold: large mammals, rodents, artic fox Coral plant or animal animal Estuary Mouth of river connects to ocean salinity 0.5 ppt-34 ppt Desert Driest of all ecosystems, daily fluctuations in temperature Succulents, deep rooted shrubs(water conservation) Animals often nocturnal and live in burrows Tropical grasslands high temperatures year-round, seasonal rainfall, frequent fires grasses and scattered trees Animals include large grazers and their predators Temperate grasslands Mild summers and cold winters, low rainfall, frequent fires Grasses Animals include large grazers, ground nesting birds, and burrowing mammals Polar Ice Cold, low precipitation Animals include many marine animals Kelp macroalgae, not plant Biogenic? Ex? produced or brought about by living organisms Coral, Kelp watershed ecosystem drained by single stream Phytoplankton Zooplankton primary producers primary consumers Adaptation vs. Acclimatization similarities and differences adaptation is a trait that helps minimize stress acclimatization is a change created(not born with) both cope with stress avoidance vs tolerance avoidance is a response to stressful environmental conditions tolerance is the ability to survive those conditions Range of tolerance: Range of intolerance Range of physiological stress Range of optimum no species low population area of greatest abundance How did amphibians adapt to tundra conditions? frog freezes outside body, creates its own antifreeze, shuts down metabolism till spring Endotherm vs Ectotherm-advantages and disadvantages endotherm generate own body heat ectotherm absorb heat from environment Mechanisms of Plants for Thermoregulation 4 ways 1. Evaporative cooling through transpiration 2. Convection • Small and smooth leaves lose heat faster than large or rough leaves 3. Pubescence • Hairs on leaf surface increases reflective property of leaves 4. Dormancy • Loss of leaves during winter or dry seasons Mechanisms of Thermoregulation- Animals 3 ways Body Size Insulation Evaporative Cooling Mammals- ---- in size from equator to poles • Larger animals • Smaller animals increase Lower surface area to volume ratio • Decreases heat lost to environment Higher surface area to volume ratio • Increases heat lost to environment Osmoconformers? ex? organisms maintain internal fluids with solute concentration equal to environment marine invertebrates, sharks, rays Osmoregulators? ex? Body fluids different concentration than environment Land Animals Freshwater Organisms Marine Vertebrates hyperosmotic? ex? (more saline) compared to environment Freshwater Organisms hypoosmotic (less saline) compared to environment Marine Organisms tolerance ability to survive stressful conditions avoidance response to stressful environment conditions stress abiotic factor lowering the potential for an organisms survival adaptation genetic trait that enhances survival due to environment acclimatization an adjustment to lessen the effect of environmental change/stress freshwater vs saltwater plants and water conservation freshwater plants spend less energy on water conservation saltwater plants have to excrete salt Primary Producers Consumers autotrophs heterotrophs 2 Processes for Primary Production photosynthesis chemosynthesis photosynthesis: terrestrial ecosystems? aquatic ecosystems? plants phytoplankton chemosynthesis producers? No Sunlight= Bacteria and Archaebacteria Can animals use photosynthesis? yes through dinoflagellates coral, jellyfish, sponges Green sea slugs have functional chloroplasts that carry out photosynthesis algae an animal? food production? yes photosynthesis Chloroplasts are taken up from food source C3 plants conserve water by closing stomata "Photorespiration" Most plants C4 plants close stomata to conserve water and use alternative enzyme high temperatures CAM plants Plants keep stomata closed during day, makes 4 carbon acid molecule at night Hot and arid Energy source: photsynthesis? chemosynthesis? sunlight chemicals Heterotrophs consumers Parasites and herbivores are ----- heterotrophs Predators consume live prey Decomposers consume dead organic matter Photorespiration plants take up oxygen, leads to breakdown of sugars, release of CO2, net loss of energy Cellular Respiration metabolism breaks down glucose to create ATP Which plants prevent photorespiraton? C4 CAM Evolution change over time Microevolution Change in the gene pool of a population over many generations Macroevolution change in groups above the level of species, often results in new taxonomic groups Genetic Drift? 2 types? Allele frequencies fluctuate unpredictably from one generation to the next Bottleneck and Founder effect Bottleneck Effect? Causes? event kills a large number of individuals and only a small subset of population is left -natural event -anthropogenic event Founder Effect? Causes? Small number of individuals colonize new location -Natural dispersal -Human-mediated transport Gene Flow Movement of alleles among populations Allopatric Speciation? result? New species arise from reproductive isolation geographic barrier Natural Selection Unequal reproduction is the essential part of natural selection Sexual Selection Individuals with certain traits are more likely to mate Sexual Dimorphism form of natural selection Sympatric Speciation New species arise in the same location as original population Mutations raw material for natural selection Limits of Natural Selection 1. Can only act on existing variation in a population 2. Limited by historical constraints 3. Adaptations are usually compromises 4. Natural selection interacts with chance/random events and the environment Directional Selection? Curve? Highest reproduction in one extreme phenotype left or right Stabilizing Selection Curve? Highest reproduction of intermediate phenotypes towards center Disruptive Selection Curve? Highest reproduction of two extreme phenotypes to both edges(high on left and right, low center) frequency of alleles: p + q= 1 genotype genetic characteristic phenotype physical characteristic alleles alternate forms of genes Adaptive radiation? usually occurs? periods of change when many new species originate from a common ancestor after mass extinction Extinction: local global mass gone from one area, present in others none left anywhere large number of species go extinct if population decreases but ratios stay the same is there evolution? no what do you expect natural selection to act on? phenotype or genotype phenotype polyploid speciation full set of chromosomes from each parent instead of half The biological species concept uses what to identify individual species? reproductive isolation