BLM 1-1, You and Food Chains/ Science Inquiry Goal: Students record their information for Starting Point Activity: You and Food Chains. 1. to 3. Answers will vary. 4. A food chain is a linear sequence of organisms that shows their feeding relationships. It starts with a producer and includes one or more consumers. It may include one or more decomposers. BLM 1-2, Flowchart of Connecting Links/ Goal: Students become familiar with terms related to ecosystems. 1. it captures energy from the Sun and, with water and carbon dioxide, converts the energy into sugar through photosynthesis 2. to capture the energy from producers by eating them and, when no longer living, to provide energy for decomposers 3. it helps to break down dead organisms and recycle nutrients in ecosystems 4. create the environmental characteristics and provide the biotic (living) factors with the necessities of life 5. a sea gull 6. an ecosystem on land 7. a land and a forest 8. crabs, earthworms, and wood beetles BLM 1-3, A Tribute to Trophic Levels/Skill Builder Goal: Students examine the concept of trophic levels. 1. 3. Answers will vary but may include the following: people deer fox fish birds insects consumers bees frogs corn rice BLM 1-4, Getting to the Top/ A deer eating animals producers wheat grains moss maggots on a dead carcass flowers mould on a rotting apple bacteria worms flies fungi beetles Goal: Students become familiar with relationships among organisms in food chains and food webs. 1. a food web 2. algae, wheat, and 3. minnow or paramecium 4. field mouse or rabbit 5. wolf 6. minnow, paramecium, mouse, or rabbit 7. herbivore 8. fourth trophic level 9. A top carnivore is a meat eater that is not food for other consumers. 10. An omnivore is a meat and plant eater. It consumes both animals and plants. 11. minnow BLM 1-5, Matching Feeder Terms/ Assessment Goal: Students assess their knowledge of terms that describe feeding relationships. The answers can be peer- or self-assessed. There is no match for (m) or (n). C B decomposers 34
1. (e) 2. (d) 3. (a) 4. (k) BLM 1-6, Analyzing Food Chains/ Goal: Students practise using terms that describe organisms feeding patterns. 1. and 2. Answers will vary. 3. (a) producer (b) Producers have the ability to capture energy from the Sun. 4. at the first trophic level, which is occupied by producers 5. Less and less energy is passed along the food chain. BLM 1-7, What Eats What?/Science Inquiry Goal: Students record their observations for Science Inquiry Activity: What Eats What? 1. 5. (b) 6. (g) 7. (c) 8. (j) 2. Answers will vary. 9. (h) 10. (l) 11. (i) 12. (f) Producer/ Organism Trophic level consumer first producer red fox third or higher consumer bacteria/fungi third or higher neither hopper second consumer cottontail rabbit second consumer red squirrel second consumer common raven third or higher neither willow first producer ruffed grouse second consumer bunch berries first producer red-tailed hawk third or higher consumer maple seeds first producer 4. All the food chains consist of at least one producer and one consumer. They are in the same sequence, going from a primary trophic level to higher trophic levels. BLM 1-8, Ecology Terms/ Vocabulary Check Goal: Students review terms related to ecology and animal feeding patterns. 1. producer 2. food web 3. decomposers 4. consumer 5. pyramid of energy flow 6. food chain 7. top carnivore 8. producer 9. herbivore 10. carnivore 11. pyramid of numbers 12. pyramid of biomass BLM 1-9, Going with the Flow/ Science Inquiry Goal: Students recognize the flow of energy in a food web. 1. (a) The population may decrease if it cannot regrow fast enough. (b) The wolf population could increase with this increased food supply. 2. Answers will vary. Here are some examples of possible food chains: Food chain 1: mouse wolf Food chain 2: deer wolf Food chain 3: shrubs rabbit hawk Food chain 4: shrubs insect frog 3. Energy Energy used Energy Organism available in metabolism stored 5000 kj 4500 kj 500 kj deer 500 kj 450 kj 50 kj wolf 50 kj 45 kj 5 kj 3. raven and hawk 35
BLM 1-10, Chains and Webs/ Goal: Students increase their understanding of relationships in food chains and food webs. 1. (a) hopper frog hawk bacteria Organism hopper frog hawk bacteria Producer/composer/decomposer producer consumer consumer consumer decomposer Trophic level first second third fourth fifth Herbivore/(top) carnivore/ detritivore/ n/a herbivore carnivore top carnivore detritivore (b) roots rabbit hawk bacteria Organism roots rabbit hawk bacteria Producer/composer/decomposer producer consumer consumer consumer decomposer Trophic level first second third fourth fifth Herbivore/(top) carnivore/ detritivore n/a herbivore carnivore top carnivore detritivore (c) tree seeds hopper hawk bacteria Organism tree seeds hopper hawk bacteria Producer/composer/decomposer producer producer consumer consumer consumer decomposer Trophic level first first second third fourth fifth Herbivore/(top) carnivore/ top detritivore n/a n/a herbivore carnivore carnivore detritivore 2. Answers will vary. Here is one example: roots rabbit tree hawk seeds hopper frog bacteria The food web here shows bacteria at the lowest trophic level. Detritivores can be placed either at the top or the bottom. Accept either answer in the food web or students charts. 36
BLM 1-11/Interaction Pyramids/ Goal: Students increase their understanding of feeding relationships in pyramids. 1. Pyramid of numbers: 3. Pyramid of energy: 7 75 750 7500 75 000 2. Pyramid of biomass: 5 kg 500 kg 5000 kg 50 000 kg hawks s sparrows beetles hawk mouse roots BLM 1-12, Feeding Relationships Quiz/Assessment Goal: Students assess their knowledge of terms that describe relationships in food chains and food webs. 1. first trophic level 2. hopper 3. 4. wolf 5. 6. consumer or carnivore 7. niche 8. terrestrial 9. food chain 10. omnivore 67 kj 670 kj 6700 kj 67 000 kj wolf s rabbits BLM 1-13, Animal Crackers/ Science Inquiry Goal: Students become more familiar with concepts related to ecosystems and interactions. Hints & Helps: You may want to give students some guidance for Part 1, step 2. You could suggest that students identify relationships from the placement of the crackers or from their knowledge of the living animals. Part 1 Because the animals are not living, and students cannot observe actual relationships, the relationships are difficult to determine. Some relationships can be inferred from the way two crackers land. For example, if the crackers land face to face, the animals could be in competition. Accept any reasonable answers. Part 2 1. injured or dead animals 2. Students should not count animals that land outside the perimeter of the sample square or on the tape. 3. (a) Answers will vary. (b) Students may mention a variety of factors, such as food availability, temperature, and human activities and intervention. (c) Answers will vary. BLM 1-14, Beef or Corn?/Skill Builder Goal: Students compare different kinds of food production. Answers will vary. BLM 1-15, Growing Bacteria/Skill Builder Goal: Students become familiar with graphic data for population growth patterns in a given time. 37
1. 600 570 540 510 480 450 420 390 360 330 300 270 240 210 180 150 120 90 60 30 0 Number of bacteria 5 10 15 20 Time (in days) 3. population density 4. competition 5. interspecific competition 6. density-dependent factors 7. density-independent factors 8. (a) Answers will vary. An example of interspecific competition is a mouse and a rabbit consuming parts of the same population. (b) Answers will vary. An example of intraspecific competition is two dogs fighting for the same piece of meat. 9. 2. availability of space (increased population density), toxicity from excess wastes, lack of sufficient food, and too high temperature from the increased population space food available soil water temperature climate BLM 1-16, Predator-Prey Patterns/ Skill Builder Goal: Students practise collecting and interpreting predator-prey population growth patterns. 1. the perimeter of the sample area being studied 2. The cards, being bigger than the paper clips, represent the lynx as the predator of the smaller prey, the rabbits. The rabbits are therefore represented by the paper clips. 3. (a) At first, the rabbit population increases very rapidly. (b) Answers will vary depending on students graphs. BLM 1-17, Population Terms/ Vocabulary Check Goal: Students become familiar with terms related to populations. 1. intraspecific competition 2. carrying capacity densitydependent factors BLM 1-18, Desertification/Science Inquiry Goal: Students identify factors related to human interaction with an ecosystem. Answers will vary. BLM 1-19, Geometric Population Growth/Skill Builder Goal: Students increase their understanding of geometric population growth. densityindependent factors 1. (a) 16 cells (b) 32 cells (c) The population is doubling with every generation. 2. (a) There are eight divisions. 1 2 4 8 16 32 64 128 256 (b) space availability (space for population growth) (c) 8 divisions 2 h = 16 h 38
3. Factors that might limit a population s growth include food and water availability and increased waste production. BLM 1-20, Population Growth Curves/Overhead Master not applicable 1. (a) cricket (b) (c) food chain (d) hawk (e) If the captured 10 000 kj of energy, the frog would have 100 kj. BLM 1-21, Biological Magnification in Nature/Information Handout Goal: Use this handout to become more aware of biological magnification in nature. not applicable 1 kj 10 kj 100 kj 1000 kj 10 000 kj hawk frog cricket BLM 1-22, Unscrambling Ecology Terms/Vocabulary Check Goal: Students review terms related to ecology. Sentences for terms will vary. 1. carrying capacity 2. competition 2. Pyramid of energy: 9 kj hawk 99 kj s 990 kj frogs 9900 kj crickets 99 000 kj 3. population density 4. pyramid of energy flow 5. biomass 6. detritivores 7. decomposers 8. trophic levels 9. ecosystem 10. producers BLM 1-23, Chapter 1 Test/ Assessment Goal: Students assess their understanding of the concepts they studied in Chapter 1. Hints & Helps: You may not want students to complete every set of questions in this test. A computerized test bank of alternative questions is available. 3. (a) A producer can take energy from the Sun and use it to produce nutrients. A consumer cannot produce its own food. It must obtain nutrients by consuming producers or other consumers. (b) A herbivore eats only plants. A carnivore eats only meat. (c) A pyramid of biomass shows biomass decreasing among organisms in subsequently higher trophic levels. A pyramid of energy shows decreasing energy available for organisms to use at subsequently higher trophic levels. (d) Competition is the rivalry among consumers for food for survival. Intraspecific competition occurs when different organisms are consuming the same food source. Interspecific competition occurs when two organisms of the same species are consuming the same food source. 4. A detritivore is a scavenger or decomposer. It can break down and recycle nutrients from waste organic material, such as dead producers and consumers. 39
5. As energy passes up through the trophic levels of an ecosystem, it decreases. Therefore less energy is available to organisms at higher levels. The amount of water and other nutrients remains constant as these nutrients flow through an ecosystem. 6. In photosynthesis, carbon dioxide is combined with energy captured from the Sun, and water, to produce food. In respiration, carbon dioxide is expelled as a waste product. 7. A top carnivore is a consumer in the highest trophic level of a food chain or food web. It is an organism that feeds on other organisms but is not itself hunted for food. 8. The biotic elements of an ecosystem are the living organisms that rely on the abiotic elements (such as the Sun, water, heat, light, and soil) for survival. 9. Carrying capacity is the limit of food, space, and other factors that support a population living in a given area. 10. (a) minnow and water flea (b) water or sea gull (c) If the minnow population became extinct, the water population might decrease, since one of the water s food sources has decreased. On the other hand, the water s other food source, the water flea population, might increase because there are fewer competitors for the algae that is the water fleas food source. Minnows are also food for the sea gulls. If there were no minnows, the sea gulls would compete with the water s for the only available food source common to both of them, algae. Since it would take a lot of algae to feed the sea gulls, it is likely that the sea gull population would decrease. 11. DDT might be sprayed on the grain to kill insects that might damage the grain before it can be harvested. When the sprayed grain is eaten by an insect, some DDT is stored in the insect s tissues. A bird that eats the insect takes the DDT into its tissues. There the DDT accumulates to become greater than the original amount that was consumed by the insect. In this way, the effect of the insecticide is magnified as it passes from organism to organism through higher trophic levels in an ecosystem. 40