Ecology Review Name: Date: Period: 1. Define the terms ecology and ecosystem. Ecology - The study of the interactions among organisms and their environment Ecosystem - collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment 2. Put the following terms into a graphic organizer or flow chart, and then define them: individual, biosphere, community, population, ecosystem, biome. Individual a single organism of a particular species Population - groups of individuals that belong to the same species and live in the same area Community - groups of different populations that live together in a defined area Ecosystem - collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment Biome - group of ecosystems that have the same climate and similar dominant communities Biosphere - contains all the portions of the planet where all life exists 3. Define the terms abiotic and biotic and give two examples for each. Biotic factors - the biological influences on organisms within an ecosystem Ex: Plants and animals Abiotic Factors the physical, or nonliving, factors that shape ecosystems Ex: Precipitation and rocks 4. List the key characteristics for the following terrestrial biomes. Biome Tropical Rain Forest Savanna Key Characteristics High precipitation Hot temperatures Most biodiversity on earth Variable precipitation Mild temperatures Mostly grasses, few trees
Desert Temperate Grassland Chaparral Broadleaf Forest Coniferous Forest Taiga Tundra Low precipitation Variable temperatures Not much plant or animal life Moderate precipitation Hot summers Mostly grasses, very few trees Low precipitation in summer, moderate in winter Hot summers Equal grasses and trees; diversity low Moderate precipitation Moderate summers, cold winters Mostly trees, few grasses; diversity high High precipitation Mild summers, cold winters Mostly trees Moderate precipitation Summer mild, winter cool Mostly trees Low precipitation Mild summers, cold winters Permafrost; no trees, some grasses 5. Explain the 3 types of dispersion patterns. Provide characteristics for each. Clumped grouped together; usually due to food availability Random spaced in an unpredictable way; flowers from where seeds land Uniform an even distribution; usually seen with territorial animals
6. The following is a survivorship curve. Provide the typical characteristics for each line. Top line - Type I produce few offspring, provide good care (humans, large mammals) Middle line - Type II intermediate, survivorship is constant over the life span. No more vulnerable at any stage. (invertebrates and rodents) Bottom line - Type III low survivorship for the very young followed by a period of high survivorship for those who live to a certain age. Large number of offspring with little care. (fish) 7. Explain the difference between exponential growth and logistic growth. Exponential growth - The population becomes larger and larger until it approaches an infinitely large size Logistic growth - when a population's growth slows or stops following a period of exponential growth 8. Human population growth is an example of exponential growth. 9. What is carrying capacity? The largest number of individuals of a population that a given environment can support 10. What are density dependent limiting factors? Give specific examples. These factors occur more when a population is large and dense Ex: competition, predation, parasitism, disease 11. What are density independent limiting factors? Give specific examples. Do not depend on the population size; affect all populations in the same way Ex: unusual weather, natural disasters, seasonal cycles, certain human activities such as damming rivers and clear-cutting forests
12. What is a demographic transition? Transition of a population from high birth and death rates to low birth and death rates. 13. What are age structure diagrams? What can they tell us about a population? Show the population of a country broken down by gender and age group Can predict future population growth 14. Explain what will be happening to the following populations in the next few years based on the age structures below. I rapid growth II declining population III slow steady growth 15. Explain the difference between the terms habitat and niche. Habitat - The area where an organism lives Niche - The area where an organism lives and how it uses the available resources 16. What does the competitive exclusion principle state? No two species can occupy the same niche in the same habitat at the same time
17. Define the following and give actual examples. Term Explanation Example symbiosis Any relationship in which two species live Shark and remora closely together commensalism one member of association benefits and the Shark and remora other is neither helped nor harmed. (+ / o ) mutualism both species benefit from the relationship. Nitrogen fixing bacteria (+ / +) parasitism one organism lives on or inside another Tapeworm and humans organism and harms it. (+ / -) predator Organism that captures and feeds on another Lion organism prey Organism that is captured and is eaten by Gazelle another organism competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time Organisms trying to eat the same food source. 18. What is succession? What is the difference between primary and secondary succession. Series of changes in a community that occur over time after a disturbance Primary - Occurs on surfaces where no soil exists. 1. A volcano destroys the land. 2. Lichens appear. 3. Mosses and grasses appear. 4. Tree seedlings and shrubs move in. Secondary Caused by natural events; soil is already present. Usually skips the lichens phase from above 19. Where does the energy in an ecosystem usually originate? SUN 20. True or False. Energy is continually recycled between biotic and abiotic factors. Explain your answer! False. Energy isn t cycled back to the sun. It flows from the sun to producers, and then through various organisms. Most of the energy is lost as heat, but it isn t returned to the sun.
21. Explain the following terms and give an example for each! Term Explanation Example Autotroph Can make their own food Plants/ algae (producer) Heterotroph (consumer) Herbivores Carnivores Omnivores Detrivores Decomposers Needs to consume food Eat plants Eat animals Eat plants and animals Eat dead material Recycle materials to the environment Humans Lion Deer Hawk Humans Hyena Bacteria and Fungi 22. Explain the relationship between a food chain and a food web. Food chain - series of steps in which organisms transfer energy by eating and being eaten. Food web interactions of food chains 23. Sketch a simple food chain below. Label the autotroph, 1 st, 2 nd, 3 rd level consumers. Include one herbivore, 1 carnivore and 1 omnivore. Producers 1 st Level 2 nd Level 3 rd Level 4 th Level Consumer Consumer Consumer Consumer
a. Add 1 animal to make it a food web. What trophic level did you add it to? Explain why it is more stable as a food web. Added in a human (just not well). This would also be a 3 rd level consumer because he likes squid. As a food web it is more stable because of energy flow. 24. What part of a food chain must include autotrophs? All levels of a food chain are dependent on the autotrophs. 25. What are the major decomposers? bacteria and fungi 26. What is a dominant species? It is the species that is most abundant in a food chain. 27. What is a keystone species? It does not have to be the most abundant but it usually plays a significant role in the food chain/ web. Usually if this species is removed the food chain/web will collapse. 28. Label the following pyramids with the correct names 500 g 1% 10 5,000 g 10% 100 50,000 g 100% 1000 BIOMASS ENERGY NUMBERS 29. Explain what quantities are lost at each trophic level and what is stored using ALL 3 pyramids. 90% is lost at each level and 10% of the original energy is passed on. 30. Where does the missing matter or energy disappear to as you move up trophic levels? EXPLAIN! It is lost as heat due to cellular respiration. Also can be lost as feces. 31. List the major process of the water cycle and explain each. Evaporation from a liquid to a gas Transpiration evaporation from a leaf Sublimation solid to a gas Condensation cloud formation Precipitation rain, snow, sleet, hail Infiltration water sinking into the ground
32. Give a brief overview of how the carbon cycle works. Explain each of the major processes. Biological processes - photosynthesis, respiration, and decomposition Geochemical processes - erosion and volcanic activity Biogeochemical processes - burial and decomposition of dead organisms and their conversion under pressure into coal and petroleum (fossil fuels) Human activities - mining, cutting and burning forests, and burning fossil fuels 33. Give a brief overview of how the phosphorus cycle works. Explain each of the major processes. Phosphate is found in the rocks. Weathering and erosion adds phosphates to the soil. Plants can take the phosphates in from the soil and we get it by eating the plants. 34. Give a brief overview of the nitrogen cycle. Explain some of the major processes. Most nitrogen is found in the atmosphere. Plants cannot use that form. Some bacteria live in the soil and on the roots of plants called legumes. They convert nitrogen gas into ammonia in a process known as nitrogen fixation. Other bacteria in the soil convert ammonia into nitrates and nitrites. Denitrifying bacteria help to return nitrogen to the atmosphere. Producers can use the nitrogen when converted and then consumers eat producers. Decomposers return nitrogen to the soil. 35. What is biodiversity? All the different organisms in the biosphere. 36. List the major threats of biodiversity. Circle the one you think is the biggest threat. a. Altering habitats - deforestation b. Pollution fossil fuels (cause acid rain) c. Hunting species to extinction d. Introducing toxic compounds into food webs biological magnification e. Global climate change f. Introducing foreign species to new environments invasive species 37. What is sustainable development? a way of using natural resources for human needs without depleting them 38. What is biological magnification? What trophic level is affected the most? Occurs when toxic compounds accumulate in the tissues of organisms. The higher up in the trophic level, the more affected the organism will be.
39. What are invasive species? Why are they a problem? How can they be controlled? Give 2 examples. They are plants and animals that humans transport around the world (accidentally or intentionally). They tend to reproduce rapidly because their new habitat has no predators to control their population. 40. How can global climate change affect biodiversity? May cause some organisms to become extinct.