UNIT 5 ARE YOU READY? SKILLS CONCEPTS • recognize the structure and function of food webs • understand trophic relationships • distinguish between carrying capacity, habitat, and niche • identify biotic and abiotic factors • contrast endangered species and invasive species • describe interactions such as symbiosis, mutualism, commensalism, and parasitism Concepts Review 1. Decide whether each statement is true or false. If you think the statement is true, copy it directly into your notebook. If you think the statement is false, rewrite it to make it true. mm (a) All the members of the same species living in the same ecosystem or habitat are referred to as a population. (b) In a food chain, energy flows from a secondary consumer to a primary consumer to a producer. (c) Every time that energy is transferred within an ecosystem, some of the energy changes form. (d) The carrying capacity is the minimum number of individuals that can be supported indefinitely by an ecosystem. (e) An ecological niche is defined as the conditions required for the survival of a species. (f) An extirpated species is a species that is close to extinction. (g) A rapid increase in a population always indicates that the ecosystem is healthy. (h) An invasive species can have a beneficial impact on an ecosystem. 2. Match each term on the left with the most appropriate description on the right. am (a) symbiosis (i) a relationship between (b) parasitism species in which one species (c) commensalism benefits and the other (d) mutualism species is unaffected (ii) an interaction between two species that live in close association with each other (iii) a relationship between species in which one species benefits by living and feeding in or on the other species (iv) a relationship between species in which both species benefit • • • • plot data on simple graphs, such as histograms and line or scatter plots interpret a graph with two vertical axes and two curves, including the relationship between the two curves solve equations that are similar to the logistic equation describe key components of a scientific journal article 3. (a) Compare and contrast food chains and food webs. Sketch an example of each. (b) How are food webs related to the concept of trophic levels? am m El 4. Explain what happens to the available energy as you move up through the trophic levels in an ecosystem. How does this affect population numbers? am 5. (a) Define the terms "biotic factor" and "abiotic factor'.' (b) Give two examples of how biotic factors can affect the abiotic factors of an ecosystem. (c) Give two examples of how abiotic factors can affect the biotic factors of an ecosystem. t:ml m 6. How would studying a population provide information about a species that cannot be gained by studying an individual? cmJ m 7. What information would biologists learn by conducting a comparison study of populations of the same species living in different locations? Im 8. In a report on invasive species, a scientist noted that zebra mussels have displaced species of native mussels that occupy similar ecological niches. The scientist also noted that zebra mussels have had a very serious impact on species that do not share the same ecological niche. cm1 ma (a) Explain why it is not surprising that an invasive species can cause harm to a native species that occupies the same ecological niche. (b) Explain how an invasive species can have a negative impact on species with entirely different niches. 9. In a prairie ecosystem, primary consumers have 100 000 units of energy in their biomass. Determine the maximum quantity of energy that tertiary consumers in that ecosystem could have. Explain how you determined this. mm m xplain the d.ifferen ce between density-cl (a) ·E · d ependent facto ependent ,1actors an d d ens1·ty-m 1o. rs. (b ) Classify the following factors as either d . d . . ens1tydependent or ens1ty-mdependent. CD!l 111 (i) food shortage (ii) increased predation l 4. A northern pike population in a portion of Lake Erie was monitored over a seven-year period. The data collected are shown in Table 1. 11.11111 Table 1 Changes in Adult Northern Pike Population (iii) forest fire (iv) climate change (v) destruction of habitat (vi) competition for mates (vii) drought (viii) introduction of an invasive species calculate the change in a population of 950 lemmings ll. after the following data were collected. Show your work. m births= 255 deaths= 103 immigration = 6 emigration = 9 12. Is the white-tailed deer population of Ontario an open population or a closed population? Explain your answer. m Skills Review 13. A culture of Lactobacilli that is being used to produce yogurt is doubling every 3 h (Figure 1). m 'iii' ftl 600 B 500 (I) S 400 E. 'iii 10 000 2006 13 000 2007 15 000 2008 16 000 2009 12 000 2010 11 000 2011 11 000 • Results • Conclusions • Abstract • Discussion • Methodology (b) Write a brief description of each section. 100 0 2005 • Introduction 300 ftl i. Population (a) Graph the changes in the adult northern pike population. Label the axes, and give your graph an appropriate title. (b) Describe and explain the growth that is illustrated by your graph. (c) Give two possible explanations for the lack of population growth in 2009, 2010, and 2011. (d) Suggest a possible reason or reasons why these scientists monitored adults instead of the entire population. 15. Scientific journals are used to present new research. The research articles in these journals have specific sections, which are presented in a particular order. IZ!I (a) List the following sections of a research paper in the correct order: Is 200 = l Year 5 10 15 20 25 30 Generations Agure 1 Population growth of a Lactobacilli culture (a) What is happening to the population of Lactobacilli up to point A? (b) ~at happens at point B? Describe what you think 18 happening after point B, and explain why. (c) What is the carrying capacity of this population? • CAREER PATHWAYS PREVIEW Throughout this unit you will see Career Links. Go to the Nelson Science website to find information about careers related to population dynamics. On the Chapter Summary page at the end of each chapter, you will find a Career Pathways feature that shows you the educational requirements of the careers. There are also some career-related questions for you to research.
