Concept explainers
SCIENTIFIC THINKING An ecologist studying plants in the desert performed the following experiment. She staked out two identical plots, which included a few sagebrush plants and numerous small, annual wildflowers. She found the same five wildflower species in roughly equal numbers on both plots. She then enclosed one of the plots with a fence to keep out kangaroo rats, the most common grain-eaters of the area. After two years, to her surprise, four of the wildflower species were no longer present in the fenced plot, but one species had increased dramatically. The control plot had not changed. Using the principles of ecology, propose a hypothesis to explain her results. What additional evidence would support your hypothesis?
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CUSTOM BIOLOGY CONCEPTS & CONNECTIONS
- Plants that colonize disturbed areas (colonizing species aka weeds) have to disperse their offspring widely so that some seeds will land in appropriate habitat. Many seeds will not land in appropriate habitat. What type of life history do you think weeds typically have? Group of answer choices many, small seeds many, large seeds few, large seeds few, small seedsarrow_forwardOwners of off-road recreational vehicles would like increased access to government-owned deserts. Some argue that it is the perfect place for off-roaders because Theres nothing there. Why do biologists disagree?arrow_forwardFigure 44.12 Which of the following statements about biomes is false? Chaparral is dominated by shrubs. Savannas and temperate grasslands are dominated by grasses. Boreal forests are dominated by deciduous trees. Lichens are common in the arctic tundra.arrow_forward
- Secession is a gradual process within an ecosystem in which some species replace other species. When a volcano creates a brand new island on rock and then plants start growing to grow this is an example of what?arrow_forwardThe ecosystem concept revolutionized ecology by introducing holistic systems thinking as opposed to individualistic life history studies. Why was this a conceptual breakthrough?arrow_forwardSCIENTIFIC INQUIRY An ecologist studying desert plantsperformed the following experiment. She staked out twoidentical plots, containing sagebrush plants and small annualwildflowers. She found the same five wildflower species inroughly equal numbers on both plots. She then enclosed oneplot with a fence to keep out kangaroo rats, the most commongrain-eaters of the area. After two years, four of the wildflowerspecies were no longer present in the fenced plot, but onespecies had become much more abundant. The control plothad not changed in species diversity. Using the principles ofcommunity ecology, propose a hypothesis to explain her results.What additional evidence would support your hypothesis?arrow_forward
- The Lazy River Environmental Group is a group of fishermen and environmentalists that have worked to assess and clean up the pollution from an old factory on the Lazy River. One early study revealed that species on the river had absorbed pollutants from the water. Select the Pollutant Levels in Tissue, by Species dataset and follow the interactive to graph the data. Which statement(s) correctly describe the graph? (Check all that apply.) The two species with highest levels are both fish.The two species with highest levels are both fish. Turtles had a pollutant level about three times that of clams.Turtles had a pollutant level about three times that of clams. No invertebrate (excludes fish and turtles) had a level above 0.05 ppm.No invertebrate (excludes fish and turtles) had a level above 0.05 ppm. The fish species with the highest level was about three times the value of the fish species with the lowest level.The fish species with the highest level was about three…arrow_forwardplant in ________are adapted to grazing and periodic fires 1- desert 2- tropical rainforest 3- grassland 4- boreal forestarrow_forwardAn insecticide is sprayed that kills the grass blackberry bushes.explain how each of the other populations of organisms will be affected If all the trees in the area were cut down,the energy supply of which population would be most directly affected?How would an increase in the oriole population affect the ecosystem? How would an increase in grasshoppers affect the rabbit population? Using evidence from the food web,explain why it is called a food"web"arrow_forward
- A scientist built a model ecosystem that contains air, plants, and animals that eat those plants. The model ecosystem is sealed so no material can get in or out, but the glass sides allow light in when the scientist switches the light on. When the scientist switches the light off, the model ecosystem is in the dark. The number of energy storage molecules in the plants and animals inside the model ecosystem started out high. Then the number of energy storage molecules began to decrease. Was the decrease because the light was switched on or because it was switched off? What happened to the amount of carbon dioxide in the air? *arrow_forwardSecession is a gradual process within an ecosystem in which some species replace other species when a forest fire destroys a certain area regeneration occurs this is an example ofarrow_forwardWhy do you suppose plants and forests appeared in large numbers before large animals did? Several of the choices may be correct. Select the options you expect to be the strongest contributing factors.Choose one or more: A.The increased oxygen levels produced by land plants accelerated animal evolution. B.Plants were driven to land by scarce resources in the oceans, such as light and minerals. C.Plants had to change less to survive on land. D.It was too cold for animals at first. E.There was not enough oxygen for lungs to be effective before plants colonized land. F.The order was pure chance and could have gone either way. G.Animals need food, and there was none on land before plants. H.Animals are more susceptible to radiation and needed more ozone in order to survive out of the water.arrow_forward
- Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning