b20 midterm Study Guide.ver0.14 (2)

Biology 20 Unit A Study Guide (25 Multiple Choice and 4 Numerical Response Questions) Explain the structure of trophic levels in ecosystems. Trophic levels describe the feeding levels through which energy and matter are transferred; indicates a consumers position in the food chain. 1st level – Producers 2nd level – Primary Consumers 3rd level – Secondary Consumers 4th level – Tertiary Consumers 5th level – Quaternary Consumers Why is less energy transferred from one trophic level to the next in an ecosystem? 80-95% of chemical energy transferred from one trophic level to the next is given off as heat or as waste products during cellular respiration due to metabolic function. How much energy is transferred from one trophic level to another? “Rule of Ten” Approximately 10% of initial energy is transferred from trophic level to trophic level. Food chains are limited in length because eventually transferrable energy dwindles to very little, which is essentially nothing. 100KJ > 10KJ > 1KJ > 0.1KJ > 0.01KJ > 0.001KJ > 0.0001KJ What do the three types of ecological pyramids represent? What units are used for each? Pyramid of Numbers: Each bar showcases the number of organisms in a specific trophic level. This allows us to estimate the amount of energy in each level but is limited because it fails to consider the size of individual organisms. The unit used is the # of Organisms. Can be inverted or upwards facing because it is possible for there to be a greater number of consumers than producers. Pyramid of Biomass: Biomass is the dry mass of living or once living things. Each bar showcases the total biomass in each trophic level. Some scientists include the biomass of dead organisms in this total, some don’t. The pyramid itself displays how the amount of biomass changes as energy is transferred from one trophic level to the next. The unit used is g/m^2. Can be inverted or upwards facing because it is possible for there to be more biomass in higher trophic levels than there is in lower trophic levels. Pyramid of Energy Removes limitations of other types of pyramids. Shows total amount of energy in each trophic level/that is transferred through trophic levels. It clearly indicates the amount of energy left at the highest trophic level. The unit used is KJ. Always is upright because ecosystems cannot survive if there is more energy in higher trophic levels than lower trophic levels. Know and Understand the Cycles of matter, how they are connected, and how humans affect them: Hydrologic Nitrogen Carbon Oxygen Phosphorus Explain how energy, matter, and the productivity of ecosystems are interrelated. Biotic and abiotic processes maintain the balance of energy and matter (equilibrium) in the biosphere. Productivity is influenced heavily by environmental factors (available sunlight, nutrients, carbon dioxide, water). Damages to DNA can hinder productivity, aka biotic and abiotic processes. An example of this is UV Radiation which damages plants DNA and limits photosynthesis. Biotic and abiotic processes depend on productivity and abiotic processes (photosynthesis) are productivity. Without them, the matter and energy equilibrium cannot be maintained. Productivity is harvested by herbivores and transferred down food chains. Some of the productivity (energy) is decomposed and some is stored. Biotic organisms DIRECTLY depend on net productivity by eating plants and INDIRECTLY by eating organisms that eat plants. Productivity provides energy. If there is not enough energy to sustain the matter on earth or create, matter quantities will decrease. This means that organisms will die, decreasing productivity even more. What is productivity? The rate at which ecosystems producers capture and store energy within organic compounds over a certain length of time. Measured as energy per area per year (J/m^2/a) or in biomass per area per year (g/m^2/a). How are food chains/food webs drawn and interpreted? Food chains use a straight line to show food (energy) transfer from producers to primary consumers to higher levels. Food webs connect food chains to showcase total food (energy) transfer throughout an ecosystem. Energy always comes from the sun and is harvested by producers which are consumed by consumers who are then consumed by consumers in higher trophic levels. Explain what happens to energy as it is transferred from one trophic level to another through the biosphere. Only 2% of the suns energy that reaches the Biosphere is absorbed and converted into chemical energy through photosynthesis by plants. Following “Rule of Ten”: 2KJ > 0.2KJ > 0.02KJ > 0.002KJ > 0.0002KJ 30% is reflected by clouds, atmospheric particles, land, or the ocean. All must have a high albedo (reflectivity). 19% is absorbed by greenhouse gases (water vapour, carbon dioxide, etc.). The energy heats the atmosphere and is slowly radiated back into space. 51% of the energy reaches Earths surface, is absorbed by land and oceans, and then radiated back into space. How does the amount of energy from the Sun that reaches producers compare with the amount of energy from the Sun that first reaches Earth’s atmosphere? 51% of the Suns energy makes it to Earth’s surface, only 2% of the 51% is absorbed by plants. Only 2% of the total energy that reaches Earths atmosphere is absorbed by plants. How is chemosynthesis like and different from photosynthesis? Photosynthesis Energy + CO2 + H2O > C6H12O6 + O2 Occurs in plants and some bacteria. Requires enough sunlight, carbon dioxide, and water. All photosynthetic organisms use solar energy to convert CO2 and H2O into glucose. Chemosynthesis Occurs in bacteria and certain fungi. Involves use of chemical energy released by inorganic chemical reactions to convert carbon (inorganic) into carbohydrates (organic). Different pathways are utilized for different species. Remember 1st law of thermodynamics: Energy cannot be created or destroyed; it can only change forms. Photoautotrophs: Photosynthetic producers that are not plants, but special bacteria capable of photosynthesis. Cyanobacteria are typically found in fresh water, ocean, damp rocky, or damp soil environments. Approximately 98% of all producers use photosynthesis, 2% don’t have access to solar energy and use chemosynthesis. Light Intensity: Limits light dependent reactions. Less light=less excitation of chlorophyll=less electrons passing through electron chain=less photosynthesis Glycerate 3 phosphate increases, triose phosphate decreases. Carbon Dioxide Concentration Limits light independent reaction. Less carbon dioxide=less available to combine with RuBP=less RuBP converted to G3P. RuBP increases, G3P decreases. Temperature Limits light independent reaction. Lower temperature=less kinetic energy=slower reactions. Higher temperatures-enzymes denature=reactions stop. What is biomagnification? Increasing concentration of toxic substances in tissues of organisms. Sources can include contaminated food sources, water sources, air pollution, etc. Once it is consumed by a singular organism it enters the food chain. Concentration is higher in higher levels of the food chain. Biology 20 Unit B Study Guide (23 Multiple Choice and 4 Numerical Response Questions) Know and Understand the following terms: Populations A group of individuals of the same species living in the same specific area at a specific time. Community All the individuals in interacting populations in a specific area. Ecosystem A community of populations together in the same area with the abiotic factors that surround and impact the ecosystem. Biosphere All the areas on earth that are inhabited by living things. Biotic Living organisms, aka animals, bacteria, decomposers, etc. Abiotic Non-living, aka plants, soil nutrients, water, carbon dioxide, etc. Biodiversity Variation of characteristics within a species. Greater biodiversity=increased chance of survival when environmental factors change. Explain how organisms are divided into domains and kingdoms. What are the different levels of taxonomy? How are humans classified? Domains: Bacteria, Eukarya, Archaea Kingdoms: Protista, Fungi, Plantae, Animalia, Archaebacteria, Eubacteria. Taxonomy: Practice of classifying organisms based on common fundamental characteristics. Danish Domain King Kingdom Philip Phyla Came Class Over Order For Family Green Genus Spinach Species Homo Sapiens are in the Eukarya domain and the Animalia kingdom. What is the agreed-upon system for naming an organism? Binomial Nomenclature System Species are given a specific two-part name: Genus Species Latin is used because it is considered a “dead language”. This means that it is not spoken in a specific place, so it is universally accepted. As well, since it is not spoken the meanings will not change overtime. Summarize Darwin and Lamarck’s theories. Charles Darwin Theory of Evolution by Natural Selection Natural selection modifies populations. Gradual environmental change builds up over time, causing only species that are fit to survive the changes to survive and reproduce, passing on their traits. Overtime, unfit species die out and populations diverge into new species due to geographical change and natural selection. On the HMS Beagle, Darwin lived through geological change such as volcanic eruptions and earthquakes, observed fossils, and viewed a variety of organisms such as different Finch species on Galapagos island. He read Lyell’s theory about Gradualism and Thomas Robert Maltice’s theory about populations increasing at a quicker rate than resources, leading to famine and only allowing the best suited organisms to survive. Wrote Zoology of HMS Beagle and Origin of Species By Natural Selection. Present forms of life have arisen by descent and modification from an ancestral species. The mechanism for modification is natural selection working for long periods of time Jean Baptiste Lamarck Theory of Inheritance of Acquired Characteristics If an organism changes during its life to adapt to its environment, those changes will be passed onto its offspring. Species increase in complexity until they reach perfection. Explain what could happen in a population when a mutation provides a selective advantage. Mutation: A change in the genetic material (DNA) of an organism. If a mutation provides a selective advantage, only organisms with the mutation will survive and reproduce, so provided the mutation is in a reproductive cell and not a somatic cell, the entire or majority of the population will come to carry the mutation. Explain how geological and biological barriers keep species separate. Geological barriers keep species physically separated, preventing interbreeding and leading to speciation. The species do not have to be separated forever for speciation to occur. However, they must be separated long enough that they become unable to mate and reproduce with original members of their population. Biological barriers are typically behavioural. Differences in mating calls, pheromones that attract males to mate, behaviours that keep populations in separate habitats, and others. The organisms are not put in the position to mate with each other, so speciation occurs because they are unable to mate with one another. Define speciation and the two general pathways to speciation. Speciation is the formation of a new species. A population must be isolated in some way for speciation to occur. Transformation New species resulting from accumulated changes in the population over a period of time. A new species develops gradually as a result of mutation and adaptation to the changing environment, replacing the old species gradually. Divergence One or more species arise from a parent species that continues to survive. Describe the relationships among mutations, variations, adaptation and natural selection. Mutations are a change in the DNA of an organism due to incorrect DNA replication. Mutations are the main source for variation within a species. Variation allows species to adapt to environmental changes through natural selection. Species with a selective advantage will survive and reproduce, those who don’t have it will die off. What different types of evidence are there for evolution? The Fossil Record Fossils found near the surface are more like species today than ones found deeper down that are much older. Fossils appear in chronological order in rock layers. Ancestors of current species are found in deeper rock layers. Not all organisms appear in the fossil record at the same time. Some species appear first and evolve into completely different species. Transitional Fossils Showcases intermediary links between different organisms, which has helped scientists to better understand the process of evolution and relationships between different groups of species. Patterns of Distribution Biogeography (the study of past and present geographical distribution of organisms) supports the ideas that: Geographically close environments are more likely to be populated by related species, rather than geographically separate environments with similar environments. Animals on islands are most like animals on the closest continent. Fossils of the same species can be found on the coastlines of neighbouring continents, suggesting that Pangaea splitting apart led to speciation and thus evolution. Closely related species are usually never found in the same geographical location, suggesting that Earth has changed geographically over time. Understand how temperature and precipitation influence plant growth. Which types of plants grow in different biomes? Temperature Earth is unevenly heated, which sets up certain conditions that produce certain air and water movements. Precipitation Patterns of precipitation determine the types of soil that form in different regions. Precipitation, temperature, topography, altitude, and latitude determine the types and abundance of plants and other photosynthetic organisms that can survive. Abundance of terrestrial life increases as the temperature and amount of precipitation increases. Biome Water Temperature Soil Plants Animals Desert Almost none hot or cold poor sparse - succulents (like cactus), sage brush sparse - insects, arachnids, reptiles and birds (often nocturnal) Chaparal (scrub) dry summer, rainy winter hot summer, cool winter poor shrubs, some woodland (like scrub oak) drought and fire-adapted animals Tundra dry cold permafrost (frozen soil) lichens and mosses migrating animals Taiga (coniferous forest) adequate cool year-round poor, rocky soil conifers many mammals, birds, insects, arachnids, etc. Temperate Deciduous Forest adequate cool season and warm season fertile soil deciduous trees many mammals, birds, reptiles, insects, arachnids, etc. Grassland wet season, dry season warm to hot (often with a cold season) fertile soil grasses (few or no trees) many mammals, birds, insects, arachnids, etc. Tropical rain forest very wet always warm poor, thin soil many plants many animals Swamp very wet warm nutrient-rich soil many plants many animals Cave (terrestrial) variable cool (and dark) rocks almost no plants few animals Biome Water Temperature Soil Plants Animals Know and understand the different types of biotic limiting factors. Competition limits population Competition for limited resources limits population because when there is not enough resources for the entire population individual organisms will have to compete for them. Predators limit population Predation is a biotic interaction where one organism consumes another organism. Consumers in higher trophic levels rely on predation to survive which in turn limits the population of the predator’s species and the population of the species they consume. Parasites limit population Parasites benefit from the host while, in turn, harming them in some way. If the host population is small, the parasites population is limited in how big it can be. If the parasites population is large, the host population is limited in how big it can be. What is meant by the term ecological niche? The role a species plays in a community and the total range of biotic and abiotic requirements it needs to survive. How can a mutation provide a selective advantage? If the mutation allows a species to survive in current environmental conditions, it provides a selective advantage. However, if the mutation serves no purpose in current environmental conditions or provides a disadvantage in current environmental conditions it will not provide a selective advantage.