Ecology Population Ecology Classwork 1. Which level of organization includes all others? 2. What does a community include? 3. The red-billed oxpecker is a bird that lives in the savanna of Africa. These birds feed on ticks and are known to rest on the backs of large mammals, such as giraffes and impalas, and eat ticks off of the mammals’ skins. Think of two questions that an ecologist would study about this interaction. 4. You notice two birds living in different parts of the same tree outside your house. They have similar markings and are a similar size. After continual observation, you realize that they cannot interbreed. Do these birds belong to the same population? 5. In reference to the birds in the above question, do they belong to the same community? 6. What is an abiotic factor? Give two examples. 7. How are a habitat and a niche different? 8. List two factors that increase population size and two factors that decrease population size. 9. Coral reefs are ecosystems that are found in ocean water that is clear, warm and shallow. A variety of animals thrive in coral ecosystems, such as reef fish, mollusks, sharks, turtles and coral vegetation. Describe three abiotic factors of the coral reef ecosystem. 10. Describe three biotic factors of the coral reef ecosystem. 11. Explain the growth rate during exponential growth. 12. Describe what is happening in a population during logistic growth. Homework 13. At what level of organization does evolution occur? 14. How is an ecosystem different from a community? 15. Deserts are found throughout the world. They are characterized by hot, dry weather with very little vegetation. Plants that live in the desert, such as cactus, shrubs and low-lying trees, have adaptations to preserve water. There are a variety of animals that thrive in the desert, such as the coyotes, desert rats, bobcats, owls, lizards and toads. Describe three components of the desert community. 16. In addition to the three components listed above, what else is included in the desert ecosystem? 17. Deserts can be found throughout the world, including in the western United States, Africa and Australia. At what level of organization would deserts be classified? 18. What is a biotic factor? Give two examples. 19. What happens if two species attempt to occupy the same niche? 20. Explain the growth rate when a population is at its carrying capacity. 21. Triggerfish are brightly colored fish that inhabit the warm, shallow waters of coral reefs. Their powerful teeth are used to eat through the protective coverings of bottom dwellers such as crustaceans, molluscs and sea urchins. During reproduction, eggs are buried in small holes in the sand. After spawning, both males and females guard the fertilized eggs. Triggerfish are known to be highly aggressive while protecting their eggs. What is the habitat of the triggerfish? 22. Describe the niche of the triggerfish. 23. Under what two conditions would exponential growth occur? www.njctl.org Biology Ecology Community Ecology Classwork 24. What is the difference between weather and climate? 25. Describe how the uneven heating of Earth’s surface causes circulation. 26. How do greenhouse gases affect climate? 27. When does competition occur? 28. Describe a win/win type of symbiosis. 29. Describe a win/lose type of symbiosis. 30. What are two terms given to organisms that are able to produce their own food? 31. What type of heterotrophs are the following animals: a) Cows only eat grass. b) Fungi break down organic matter. c) Lions eat other mammals. d) Earth worms eat decaying plants and animals. e) Bears eat both vegetation and meat. 32. What do food webs/food chains illustrate? 33. What is ecological succession? 34. Describe the process of primary succession from bare rock to climax community. Homework 35. List two factors that produce climate. 36. List two factors that produce weather. 37. How does climate change affect species? 38. How does predation drive co-evolution of predator/prey species? 39. Describe a win/neutral type of symbiosis. 40. What are two terms given to organisms that rely on other organisms for food? 41. In a food chain, if an arrow points from an insect to a bird, what does this mean? 42. What is the difference between a food web and a food chain? 43. What is the difference between primary succession and secondary succession? 44. What is a pioneer species? 45. What is a climax community? Nutrient Cycling Classwork 46. How do transpiration and evaporation differ? 47. Draw a flowchart illustrating the cycling of water via the following processes: condensation, evaporation, precipitation, runoff, transpiration. 48. Where is most carbon found? 49. Describe how removing all plants would affect the carbon cycle. 50. How do geochemical processes affect atmospheric carbon? 51. Why is nitrogen important to all organisms? 52. How is nitrogen changed into a useable form? 53. When organisms die, what process returns nitrogen into the soil/atmosphere? 54. Why is phosphorous important to all organisms? 55. Where is most phosphorous found? Homework 56. What two processes are sources of water for cloud formation? 57. After water has formed clouds in the atmosphere, what two processes bring water back to the oceans? 58. Describe two ways in which humans release carbon into the atmosphere. www.njctl.org Biology Ecology 59. How do dead organisms contribute to the carbon cycle? 60. In what form is most nitrogen found? 61. Describe the type of symbiosis that carries out nitrogen fixation. 62. How does phosphorous make its way to marine organisms? 63. How does phosphorous make its way to terrestrial organisms? 64. Phosphorous is a limiting nutrient for most plants. What does this mean? 65. How can overusing fertilizers result in decreased aquatic life? Conservation Biology Classwork 66. What is biodiversity? 67. How do disturbances affect biodiversity? 68. What does it mean to say that an ecosystem is resilient? 69. What is a natural resource? 70. How did technologies invented during the Industrial Revolution impact population growth? 71. How does hunting affect biodiversity? 72. Describe two ways that environmental degradation affects ecosystems. 73. What is an invasive species? 74. Why do invasive species reproduce rapidly? 75. What is the purpose of conservation? 76. What is the purpose of sustainable development? 77. List three sources of alternative energy. Homework 78. List two examples of disturbances to biodiversity. 79. How did the Industrial Revolution impact the use of natural resources? 80. What is a renewable resource? Give an example. 81. What is a nonrenewable resource? Give an example. 82. Describe two ways that farming impacts the ecosystem. 83. Describe two effects of global warming. 84. Describe two effect of invasive species. 85. Describe one method for conserving each of the following: Land Water Atmosphere Biodiversity Energy 86. What is a pro and a con of using: Biofuels Nuclear energy 87. Why are bioplastics preferable to regular plastics? 88. Some climbing robots mimic the adhesive properties of gecko feet. What is this an example of? www.njctl.org Biology Ecology Free Response 1. The carbon cycle is the pathway of carbon through the biosphere. a. Describe the importance of photosynthesis and cellular respiration to the carbon cycle. b. How has human behavior affected the carbon cycle? 2. Antarctica is home to several species of penguins, including the Adelie and the Chinstrap. Adelie penguins live on ice packs while Chinstrap penguins live mostly in the open water. Over the past 50 years, the midwinter temperature of western Antarctica has increased 7-9⁰ C. In response to that, the Adelie population has decreased 22% over the past 25 years while the Chinstrap population has increased roughly 400%. a. Propose a reason for the different growth patterns for Adelie and Chinstrap penguins in western Antarctica over the past 25 years. b. Over the past 25 years, what type of growth has the Chinstrap penguins experienced? For how long will this growth pattern continue? c. Why is it impossible for both the Adelie and the Chinstrap penguins to inhabit the same niche? 3. The Sargasso Sea is a gyre in the middle of the Atlantic Ocean that is created by the convergence of four different oceans currents. Although classified as the open ocean, the Sargasso Sea often is teeming with life. One important habitat in the Sargasso Sea is large floating mats of sargassum, a brown seaweed. This seaweed is washed into the Sargasso Sea from coastal areas by the many different currents. Since the seaweed floats on the surface, many organisms use the seaweed as an ecosystem in which to live. Turtle hatchlings use sargassum mats as nurseries; shrimp, crabs and fish live in sargassum; tuna and birds use sargassum as hunting grounds. A common fish in this habitat is the planehead filefish. These fish are very slender with small fins and a retractable file on the head. They are mottled brown in appearance, which allows them to hide well in the sargassum. Filefish have a varied diet of algae and invertebrates, most of which can be found in the sargassum ecosystem. Spawning sites are prepared by the males, although both males and females may guard the site. a. How do ocean currents form? b. What is the difference between a niche and a habitat? Use the planehead filefish as an example. 4. Nitrogen is an essential nutrient for all organisms. While most nitrogen is found as a gas in the atmosphere, many organisms are unable to use gaseous nitrogen. a. Why is nitrogen an essential nutrient? b. Describe fully the interaction between Rhizobium and plants. How does this benefit organisms? www.njctl.org Biology Ecology 5. The image below shows a food web for polar bears. Use it to answer the following questions: Source: EPA.gov a. What is the difference between abiotic and biotic factors? Give two examples of each, based on this food web. b. Ice algae are algae that grow in pockets of sea ice and are consumed by zooplankton. In terms of ice algae abundance, how would continual global climate change affect the polar bear population? www.njctl.org Biology Ecology Ecology Answer Key 1. The biosphere includes all other levels of organization. 2. A community includes all the populations in a specific area. 3. An ecosystem includes all the living and nonliving factors in an area while a community only includes the living factors. 4. Answers will vary. 5. They do not belong to the same population because they cannot interbreed (they are separate species). 6. An abiotic factor is a nonliving factor in an ecosystem. Examples: sunlight, precipitation, temperature, wind, soil and nutrient availability. 7. A habitat is where an organism lives. A niche describes how the organism lives. 8. Increase population: immigration and births. Decrease population: emigration and deaths. 9. Temperature, depth, and turbidity (how clear the water is) 10. Answers will vary. Examples: fish, molluscs, sharks, turtles, coral vegetation. 11. During exponential growth, the growth rate remains constant. 12. During logistic growth, a population initially experiences unlimited resources that leads to exponential growth. As the population size outgrows the resources, however, the growth rate decreases until the population reaches the carrying capacity. 13. Evolution occurs at the population level. 14. They belong to the same community because they live in the same area. 15. Answers will vary (any three populations). 16. Nonliving factors such as hot temperatures and lack of precipitation. 17. Biome 18. A biotic factor is a living factor in an ecosystem. Examples: plants, animals, fungi, bacteria. 19. Competition between the two species will displace one of the species into a different niche. 20. At the carrying capacity, the growth rate approaches zero. 21. Coral reefs 22. Triggerfish use sharp teeth to eat molluscs, crustaceans and echinoderms. Eggs are buried in the same and both sexes take part in caring for fertilized eggs. 23. Exponential growth occurs in the absence of predation/disease or in the presence of unlimited resources. 24. Weather is the conditions present at a particular place and time. Climate is the average weather of a location. 25. Uneven heating of the Earth’s surface causes wind circulation. 26. Greenhouse gases trap the sun’s energy which results in warmer climates. 27. Competition occurs when organism try to obtain the same resources at the same time and place. 28. In mutualism, both species benefit from the relationship. Examples will vary. 29. In parasitism, one species benefits while the other species is harmed. Examples will vary. 30. Autotrophs and producers 31. a) herbivore; b) decomposer; c) carnivore; d) detritivore; e) omnivore 32. Food webs/food chains show the flow of energy in an ecosystem. 33. Ecological succession is the series of changes that occur in an ecosystem over time. www.njctl.org Biology Ecology 34. Lichen and moss grow on bare rock. When they die, the nutrients added to the ground become soil. Grasses, small plants and then climax communities follow as the soil becomes better able to sustain life. 35. Climate is caused by latitude, altitude, land masses, wind, ocean currents, atmospheric interactions and precipitation. 36. Weather is caused by wind, temperature and precipitation. 37. Species are adapted to the climate of their ecosystem. If the climate changes, they may not have the adaptations necessary to survive in the new conditions. 38. As prey evolve adaptations to escape predators, the predators evolve adaptations that allow them to become better at capturing prey. One adaptation drives the evolution of the other adaptation. 39. In commensalism, one species benefits while the other species is neither harmed nor benefitted. Examples will vary. 40. Heterotrophs and consumers 41. This means that the bird eats the insect. 42. A food chain shows one pathway of energy in an ecosystem. A food web shows all pathways of energy in an ecosystem. 43. Primary succession occurs when a community forms where there was previously no life. Secondary succession occurs when a climax community reforms after a drastic event. 44. A pioneer species is the first organism to populate an uninhabited environment. 45. A climax community contains the organisms that remain stable in an ecosystem over time. 46. Evaporation occurs when liquid water changes into gaseous water in the atmosphere. Transpiration occurs when liquid water evaporates from plants. 47. Evaporation/transpiration condensation precipitation runoff 48. Most carbon is found in the atmosphere. 49. With no plants, there would be no pathway to remove carbon from the atmosphere. 50. Geochemical processes release carbon into the atmosphere. 51. All organisms use nitrogen to build proteins. 52. Nitrogen is changed into useable form via nitrogen fixation. 53. Denitrification releases nitrogen back into the soil/atmosphere when organisms die. 54. Phosphorous is used to build ATP, DNA and RNA. 55. Most phosphorous is found in rocks and sediment. 56. Transpiration and evaporation 57. Precipitation and runoff 58. Answers may vary. Cellular respiration, mining, forest fires, and the burning of fossil fuels. 59. Under pressure, dead organisms are converted into fossil fuels. 60. Most nitrogen is found as a gas in the atmosphere (N2). 61. Mutualism between bacteria and legumes. The bacteria carry out nitrogen fixation in exchange for nutrients from the plant. 62. When phosphate is released from rock, some of it is washed into waterways where it is used by marine organisms. 63. When phosphate is released from rock, some of it remains in the soil where it is taken up by plants. 64. Phosphorous is a limiting nutrient, meaning that plants will not grow unless they have an adequate supply of this nutrient. Their growth is limited by the availability of this one nutrient. 65. When fertilizers are overused, excess nutrients wash into the waterways. The nutrients are used by aquatic producers, causing algal blooms. The enlarged population of www.njctl.org Biology Ecology producers uses all of the oxygen in the water. The lack of oxygen causes other aquatic species to decrease. 66. Biodiversity is the variety of plants and animals on Earth. 67. Disturbances remove species from ecosystems which decreases biodiversity. 68. A resilient ecosystem is able to recover from a disturbance. 69. Natural resources are factors that occur naturally in an ecosystem and can be used to fulfill the needs of organisms. 70. Technology during the Industrial Revolution led to a substantial increase in world population. 71. Hunting decreases biodiversity by removing or severely limiting species. 72. Answers will vary. 73. An invasive species is a foreign species that is transported to a local ecosystem. 74. Invasive species reproduce rapidly because they have no natural predators to regulate their population size. 75. Conservation preserves healthy ecosystems by managing natural resources and communities. 76. Sustainable development aims to use resources in such a way that the needs of humans and ecosystems are met. 77. Hydro, nuclear, biofuel, solar, wind 78. Fire, flood, drought, human activity 79. The Industrial Revolution substantially increased the use of natural resources. 80. Renewable resources can be regenerated by nature. Examples will vary. 81. A nonrenewable resource cannot be replenished by nature. Examples will vary. 82. Answers will vary. 83. Answers will vary. Melting ice caps, rising sea level, coastal flooding, disruption of habitat 84. Answers will vary. Prey on native species, outcompete for resources, disease, disruption of native reproduction 85. Answers will vary Land – windbreaks, crop rotation, terrace, replanting Water – restore wetlands, prevent waste, prevent pollution, reuse gray water, low flow shower heads and toilets Atmosphere – remove fossil fuels, remove/limit pollutants Biodiversity – ban the dumping of waste, protect land, breeding programs Energy – limit car transportation, use energy efficient products 86. Answers will vary. Biofuels – PRO: renewable, less CO2. CON: reduces food supply, requires energy Nuclear energy – PRO: high amounts of energy, reduces carbon emissions. CON: possibly harmful radiation, must be stored properly 87. Bioplastics can be decomposed while regular plastics cannot. 88. Biomimicry 1. a. Photosynthesis and cellular respiration have opposite effects on the carbon cycle, via CO2. Photosynthesis removes carbon from the atmosphere while cellular respiration recycles carbon back into the atmosphere. b. Human activity has increased the burning of fossil fuels. This releases abundant CO2 into the atmosphere and drives global climate change. www.njctl.org Biology Ecology 2. a. As temperatures have increased, sea ice has decreased. This has decreased the habitat of Adelie penguins while simultaneously increasing the habitat of Chinstrap penguins, leading to the different growth patterns. b. Chinstrap penguins have been experiencing exponential growth. This will continue until the population grows to such a size that competition for resources occurs. At this point, the growth rate will approach zero as the population reaches its carrying capacity. c. Two species cannot occupy the same niche at the same time. When this happens, competition for resources will displace one of the species into a different niche. 3. a. The uneven heating of the Earth causes warm water at the equators and cold water at the poles. As cold water sinks, warm water remains at the surface and is moved via wind. This results in the ocean currents. b. A habitat is where an organisms lives. The habitat of the planehead filefish is sargassum mats. A niche is a description of how an organism lives. The planehead filefish hide in sargassum mats and eat algae and invertebrates. The males build spawning sites which are heavily guarded by both males and females. 4. a. Nitrogen is used by all organisms to build amino acids, which are used to build proteins. b. Rhizobium is a bacteria that participates in a mutualistic relationship in the roots of legumes. They fix atmospheric nitrogen into a form that can be used by plants. In exchange, they receive nutrition from the plants. This mutualistic relationship benefits all organisms in that it provides nitrogen in a form that can be used by organisms. 5. a. An abiotic factor is a nonliving factor in an ecosystem, such as sunlight and nutrient availability. A biotic factor is a living factor in an ecosystem, such as zooplankton and seals. b. As climate change continues, sea ice will decrease. This will cause a decrease in ice algae populations. In turn, zooplankton populations will decrease which will cause similar changes up the food web. With less food available, polar bear populations will also be negatively affected. www.njctl.org Biology Ecology