Community Ecology Chapter 5

Transcription

1 Evolution and f^tf Community Ecology Chapter 5 Lab Manual Name Period TEACHER

2 NAME Directions: Read the categories below and then read the Case Study. As you read, fill in the table. You must have at least term in the vocabulary box and a clear thought/explanation in each otuie other BLACK AND WHITE AND SPREAD ALL OVER-PAGE 125 ( - ^-^LobS SEEMS IMPORTANT TO ME SOMETHING I DON'T UNDERSTAND X SOMETHING I DON'T AGREE WITH WORDS/TERMS THATSEEM IMPORTANT SOMETHING ELSE WANT TO TALK ABOUT

3 DISCOVERY CHANNEL: SCIENCE OF SEX APPEAL V I ADAPTATION SELECTIVE PRESSURE (WHAT IS THE BENEFIT FOR SPECIES survival?) SYMMETRY WOMEN ARE CHOOSIER BODY SHAPE FEMALE ESTROGEN ON VOICE COPULANCE (FEMALE SCENT) ON MEN SEXY VOICES SIGNAL FROM THE FLESH ATTRACTIVE MALE FUNK (SWEAT)

4 Name Environment and Ecology Date D A RW I N ' S T H E O RY O F E V O L U T I O N Organisms with the most favorable t r a i t s f o r t h e i r environment will survive (ie. Survival of the Fittest) NATURAL SELECTION-over time the predominant features of a population may change as nature "selects" the ones with the best features to survive 1

5 Environment and Ecology NATURAL SELECTION LAB PROCEDURES 1. Observe your tray. If it is green, you need a set of squares. If it is black, you need a set of moths. 2. Place the moths or squares into the tray. Stir and spread the items out. 3. While looking at the contents, have another students quickly select out five moths or squares, one at a time. 4. Set those five items aside. 5. Take each moth and compare it to the chart. Record on tally sheet which color moths were selected. Take each square and compare it to the size of the sorted squares. Record on tally sheet which squares were selected. 6. Repeat with as many students as possible until your teacher says it's time to trade trays. 7. Groups with dark trays and moths trade with those groups having green trays and squares. 8. Repeat steps Return the moths and squares to the resealable bags. 10. Tally all results as a class in the last row of the data table. 2

6 Environment and Ecology KETTLEWELL STUDY Moth color over time Dr. Kettlewell compared the color of the moths in a mainly white/light bark forest to the moths stored in a museum that had been collected from the same forest over 100 years ago. What he discovered illustrates a basic concept in biology. In a population of moths, there will be a normal distribution curve of colors. Most of the moths will be average in color. A few will be lighter and a few will be darker. Draw what that would look like below: N u m b e r o f M o t h s m a n y few l i g h t m e d i u m d a r k 1. Observe Kettlewell's data. What kind of moth would be eaten by the birds more frequently? Why? 2. If the uneaten moths mated, what color offspring would they tend to have a few more of? 3. Imagine the nearby city become more developed and smoked poured out of the chimneys and settled on the tree trunks. What happened to the color of the tree trunks as time progressed? 4. What kind of moth would be eaten now by the birds more frequently? Why? 5. If the uneaten moths mated, what color offspring would they tend to have a few more of? 3

7 Environment and Ecology 6. As the years continued, the trees became darker and darker. If the surviving moths of each generation were to continue to mate, what do you think would happen in time to the color of the entire population? 7. What caused the evolutionary color change in the moth population? 8. What difference will give some human individuals a better chance of survival? 9. How does Natural Selection (ie Survival of the Fittest) apply to your life? a. Dating b. Your family (who do you look like, act like?) c. Plans for the future d. Are you "good" at the same subjects as your parents? e. Are you "good" at the same sports as your parents? 4

8 Environment and Ecology DATA TABLE-MOTH COLOR NUMBER OF EACH MOTH SELECTED NUMBER OF EACH MOTH SELECTED NUMBER OF EACH MOTH SELECTED NUMBER OF EACH MOTH SELECTED GROUP TOTAL WHITE C L A S S T O TA L DATA TABLE-GREEN SQUARES SIZE NUMBER OF EACH SQUARE SELECTED NUMBER OF EACH SQUARE SELECTED NUMBER OF EACH SQUARE SELECTED NUMBER OF EACH SQUARE SELECTED GROUP TOTAL C L A S S T O TA L 5

9 Environment and Ecology Analysis and Discussion: 1. When the respective rows of colored moths or squares are arranged in a single file from white to black or small to large, there is an equal number of objects on either side of the middle. What is this called? 2. Look at the class data for which colored moths were selected. Add up all the numbers on either side of the middle number. Do NOT include the middle number in the count. Did the class select out more lighter-colored moths or more darkercolored moths? 3. How would you explain the class results? 4. Repeat step 4 for the squares. Did the class select out more smaller-sized squares or more larger-sized squares? 5. How would you explain the class results? 6

10 Environment and Ecology Mrs. Kir man bate Bottleneck Senes Background: The ability of an individual to survive changes in the environment increases the more genetic diversity the individual has. "Survival of the Fittest" indicates that an organism must have the genetic resources to allow it to survive immediate changes in the environment and that allow the species to adapt to the long-term changes around it. In this laboratory, you will be exploring the life of a black-footed ferret trying to survive immediate changes and pass on long-term traits to your off spring. However, the number of individuals in your population has drastically decreased due to habitat loss and/or degradation. This caused a BOTTLENECK in the gene pool and you did not get all the traits in the gene pool. Your goal: Survival DIRECTIONS: 1. You are given a baggie with colored beads that indicate a genetic trait and slips of paper that indicate events that happen in your life. Each different colored bead indicates a different genetic trait you have inherited from your parents. See the chart below and check off the traits you have inherited. 2. Pull out one slip of paper, read, and record the scenario in the data table. As a group, determine whether you have the genetic traits to survive this event. Continue until all your slips of paper have been analyzed. 3. Finally, complete the analyze and conclude questions. KEY TO GENETIC CHARACTERISTICS Color of Bead Yellow Black Pink Dark blue Green Red le White G e n e t i c C h a r a c t e r i s t i c Camouflage Precise vision Accurate sense of smell Strong claws and forearms Healthy Jaw formation Acute hear in Healthy rate of reproduction Immunity to canine distemper Check-off

11 Environment and Ecology Mrs. Kirman Sunr\marize each scenario you encounter Predict: Explain why you think you did or did Survive (S) not survive as a result of your o r D i e ( b ) g e n e t i c m a k e - u p ANALYZE AND CONCLUDE: 1. Calculate the percentage of genetic diversity of your population. lenes received / 9 original genes =.(decimal) x 100 % 2. Which characteristics did your ferret lose through the bottleneck? 3. Predict what will happen to your population in the coming year.

12 Evolution and Selection What mechanisms lead to changes in the diversity of species on Earth? Why? People make choices by selecting options they like best. The natural world also "selects" (although not as a conscious decision) when envu*onmental conditions allow organisms with a particular genetic trait to live healthier lives than other organisms. In this activity, we will explore how selection affects populations over time. Model 1 - Desktop Swab Results E. coli baaerial variants from culture Variant P ^ Variant Q Variant R ^ V a r i a n t s A E. coli culture from swab of desktop E, cou colonies on growth medium without triclosan E. coli colonies on growth medium with triclosan 1. What is the source of the bacteria in the culture tube in Model 1? 2. How many genetic variants of Exoli were present in the culture from the initial swab? 3. What variants of E.coli are found on the dish grown without triclosan? 4. Refer to the dish in Model 1 with the medium that included triclosan. a. What variants of E.coli are found on the dish grown with triclosan? b. What likely happened to the other variants of Exoli on the dish with the medium containing triclosan? Evolution and Selection 1

13 5. Based on its effea on Exoliy why is triclosan used as a cleaning agent? 6. Suppose the desktop swabbed earlier was cleaned with a solution containing triclosan. Would living E.coli remain? Support your answer. 7. Suppose the desktop was swabbed again after cleaning it with triclosan over a 9-month school year. When the sample was cultured only variant S was seen. a. What charaaeristic does the variant S baaeria have that allows it to remain on the desktop even after several months of treatment with triclosan? b. Is it likely that the baaeria in the new swab were on the desk 9-months ago, or are they off spring of the original bacteria? c. Propose an explanation for the presence of only variant S on the desktop after so much time. Read This! Populations of most living organisms exhibit genetic diversity among individuals. Certain traits in a population give some organisms a greater chance of survival than individuals that lack these traits. Because these traits tend to increase the chance of survival, these individuals may produce more offspring that will also have the trait that favors survival. Over time, the number of individuals within the population pos sessing the favorable trait increases while the number of oflfepring with the favorable trait decreases. 2 POGIL^ Activities for High School Biology

14 Model 2 Color Variations in Moths in Great Britain Peppered Modi Frequency.1" 70 a B O I so I 3 0 G li^t moths Daik moths 8. Refer to the graph of Peppered Moth Frequency in Model 2. a. Which moth color was more prevalent before 1850? b. Which color was more prevalent between 1900 and 1950? 9. Describe the change in the percentage of light-colored moths and dark-colored moths between 1850 and Describe the change in the percentage of light-colored moths and dark-colored moths between 1950 and During the Industrial Revolution through the mid-20th century, feaories and power plants, which burned coal, produced large quantities of soot and smog. Near industrialized areas, black powder covered surfaces, including the moth habitat. a. Which color moth would have a better chance of surviving predation (better camoflage to hide from predators) on this dark surface? b. How does this help explain the change in the colors of the moth population shown in Model 2? Evolution and Selection 3

15 12. Clean Air Acts were passed by governments of industrialized nations beginning in the mid- 1950s. Use this information to explain why the color of the moth population shifted again. Model 3 Natural vs. Artificial Selection Dog Gray Wolf Red Wolf Coyote 13. Model 3 traces the lineage of what organisms? - Artificial selection 14. How does Model 3 indicate that all three types of organisms came from a common ancestor? 15. According to Model 3, wolves (gray and red) are more closely related to what other group dogs or coyotes? Explain your answer. 16. Think about the characteristics of the organisms above. a. What are some differences that you note between wolves and dogs? k What similarities can you identify? 4 POGIL^ Activities for High School Biology

16 17. Modern domesticated dogs arose from wolves through selective breeding by humans. a. What traits might humans have selected in the common ancestor of dogs and wolves that would account for the differences between dogs and wolves? b. According to Model 3, what is the name of this type of selection? Read This! The events that lead to changes in groups of organisms are called selecdon by evolutionary biologists. Charles Darwin ( ) is the person credited with carefully outlining how various changes in populations of organisms might occur through time. He called this process natural selection. Humans participate in seleaion through selective breeding of plants and animals. This is referred to as artificial selection. 18. Is the selection that led to the development of wolves and coyotes an example of natural selection or artificial selection? Explain your choice. 19. Refer to Model 1. Is the selection leading to changes in the E. coli variants natural or artificial selection? Explain your choice. 20. Two differences between red and gray wolves is their color and size. What environmental condi tions might have resulted in selection for red wolves and gray wolves? i21. Refer to Model 2. Is the selection of moths that blend in to their environment an example of natural or artificial selection? Explain your choice. Evolution and Selection 5

17 Extension Questions 22. For the past 10 to 25 years, farmers have planted crop seeds that have been geneticaly modified to withstand treatment with a common weed killer called Roundup. This allows the farmers to spray their fields to get rid of weeds without harming their crops. Recendy, more and more farm ers have discovered that their fields have Roundup-resistant pigweed growing along with their crop. Use what you've learned in this activity to explain how this came about. 23. Many popular products from hand soap to clothing advertise that they have antibacterial quali ties. Most microbiologists recommend agsdnst their routine use in our daily lives. How can you explain this using your knowledge from this activity? 6 POGIL Activities for High School Biology

18 Compare / Contrast With Summary Concept 1 Concept 2 STRUCTURAL ADAPTATION BEHAVIORAL AbAPTATION \ How Alike? / How Different? With Regard To \ SURVIVAL FIND FOOD SURVIVE COLD/HEAT REPRODUCTION AVOID PREDATORS Summarize:

19 Environment and Ecology Name: Date: Period: (0/E) WELD AMERICA: DESIGNS FOR DEFENSE VIDEO WORKSHEET What are some adaptations that have enable predators to be successful? Describe at least two! 2. What's the opossum's first line of defense when faced with a predator? 3. Why do most predators need their prey to put a fight? Are opossum's just play acting when they "play possum"? Explain. What's the main and final defense mechanism used by the hognose snake to avoid being eaten by the badger? 6. What animal attacked the coral snake? Continued on the back

20 7. What is the probable reason why the coral snake didn't bite its attacker? 8. What's the main and final defense mechanism used by the gecko? How did this help it? 9. What caused the grouse to be eaten by the gyrfalcon? 10. How did uistinct fail the tree frog when it confronted the "spiny" caterpillar? 11. Can porcupines throw their quills? Explain 12. Antler growth, because of how quickly the cells grow, has been studied m relation to what human disease? 13. In the battle between the two mule deer, which one won: the larger or the smaller? 14. In the final part of the video, Marty says that none of these creatures have developed the deadly weapons or complex intelligence that we associate with their more highly developed predators. Who/What is he referring to?

21 Name_.Date_ Wildlife Specimen Lab Background: In order for a species to survive, it must adapt to its environmental conditions, acquire food, fight off predators, and build or find shelter. If it is unable to do this, it does not survive. We call these special, inherited characteristics adaptations. Directions: Observe each wildlife specimen. (Most can be found in Pennsylvania) Fill in the data table. Specimen # and color What is it? (skull, carapaces, feather, wing, talon, pelt, other) What animal or How does it help the animal type of animal survive? does it belong to?

22 Specimen What is it? (skull. What animal or How does it help the animal # and carapaces, feather, type of animal survive? color wing, talon, pelt, does it belong o t h e r ) W

23 Ecological Relationships What symbiotic relationships are seen in ecosystems? Whyi All living organisms need each other in some way to survive. This can include the interactions between predators and their prey, the close associations between and among living things (symbiosis), or the com petitive relationships between and among species. Al of these relationships may be equaly advantageous to the parties involved, or they may be more beneficial to one organism over the other. Model 1 - Predator-Prey Relationships Relationship between Snowshoe Hares and Lynx Year 1. Refer to the graph in Model 1. a. What does the y axis on the left represent? b. What does the y axis on the right represent? c. For both y axes, what value do the numbers on the axes need to be mulriplied by? 2. What was the approximate population of snowshoe hares in 1865? Ecological Relationships

24 3. What was the approximate population of lynx in 1865? 4. When the number of snowshoe hares is high, what happens to the number of lynx? Use actual data from the graph to support your observation. 5. What happens to the population of lynx as the number of snowshoe hares decreases? Use actual data from the graph to support your observation. 6. Propose an explanation for die apparent cause and efea relationship between the populations of lynx and hares. 7. What does this information tell you a. about the effect of size of prey populations on the number of predators? b. about the effect of predators on the populations of their prey? 8. What other factor would influence the size of the hare population in addition to the size of the population of lynx? 2 POGIL*** Activities for High School Biology

25 Model 2 - Symbiosis Organism 1 Organism 2 Description of the relationship Symbiotic Relationship Dog Flea The flea feeds on blood from the dog. There is no benefit to the dog and the itching and bites may lead to infection. Fungus Algae The photosynthetic algae provide food for the f^gus, which in turn provides a suitable living environment for the algae. Termite Cellulosedigesting baaeria The baaeria in the gut of the termite breakdown and feed on some of the cellulose taken in by the termite. The termite would be unable to digest cellulose without these baaeria and they gain an additional source of nutrition firom the surplus digested cellulose. Shark Remora The Remora fish swim alongside the shark and take scraps of food that the shark drops during feeding. The shark does not eat the Remora and appears unaffeaed by its presence. Catde Catde egret The catde egret follows herds of catde and eats the insects that the catde stir up as they move through the grassland. The catde appear to be unaffeaed by the egrets. Human Tapewonn The tapeworm lives in the small intestines where it feeds and grows, robbing the human of essential nutrients. 9. Refer to the information given in Model 2. a. In the dog and flea relationship, is there a benefit for one of the organisms or for both? b. Is either the dog or the flea harmed by this relationship? c. Which other relationship in Model 2 is similar to that between the dog and flea? Ecological Relationships 3

26 10. Refer to the fungus and algae relationship in Model 2. a. Is there a benefit for one of the organisms or for both? b. Is either the fungus or the algae harmed by this relationship? c. Which other relationship in Model 2 is similar to that between the fungus and the algae? 11. Refer to the shark and remora relationship in Model 2. a. In the shark and remora relationship, is there a benefit for one of the organisms or for both? b. Is either the shark or the remora harmed by this relationship? c. Which other relationship in Model 2 is similar to that between the shark and the remora? Read This! Symbiotic relationships are identified by how they aflfea the organisms involved. The three types of sym biotic relationships are listed below. Mutualism: Both organisms benefit j&om the relationship. Parasidsm: One organism benefits and the other is harmed. Commensalism: One organism benefits and there is no effect on the other. Using the information firom the Read This! ho:^y label each of the relationships in Model 2 as mutualism, parasitism or conmiensalism. 13. With your group, choose one of the organism pairs from Model 2 and justify why you catego rized the relationship as you did. 4 POGIL'** Activities for High School Biology

27 Model 3 - Inter- and Intra-specific Competition Graph A Graph B A P. aurelia and P. caudatum grown separately A P- aurelia and P. caudatum grown together,p. aurelia c o P. coudatum Number of Days Number of Days Graph C Rate of growth of R. tigrina tadpoles in populations of different sizes. I «0. 4 // / / // ^ / / ^ U / / /* / -Minimum mass needed for metamorphosis to occur. 5 individuals 40 individuals 60 individuals 160 individuals Time (weeks) 14. What are the names of the species in graphs A and B in Model 3? 15. Which graph shows competition between two different species? 16. Which graph in Model 3 shows poptdation growth for only one species? 17. What is the difference between the growing conditions in graph A and graph B? Ecological Relationships 5

28 18. /? caudatum and P. aurelia are both species of Parameciunh a microscopic protozoan. R caudatum is the larger of the two species. When grown separately, which of the two species reaches a larger relative population size after 20 days? 19. When grown separately is there a substantial difference in the relative population size of the two types of paramecia after 20 days? 20. Compare graphs A and B in Model 3. a. Which population of species of Paramecium is more afifected when the two species are grown together? b. Considering that R caudatum is 50% larger in size than R aurelia, develop a hypodiesis with your group to explain why intetspecific competition has an effect on the relative population size of R caudatum. ^21. In a grammaticaly correct sentence, define interspecific competition. 22. Refer to graph C in Model 3. a. Describe the species of organism represented by the graph. b. These tadpoles are confined to a limited environment. What are they al competing for in that environment? 23. What is the minimum mean body mass requked for metamorphosis of a tadpole to occur? 24. When there are only five tadpoles, how long does it take for metamorphosis to occur? 25. When the number of individuals is increased to 60, what is the effea on the time taken for metamorphosis to occur? 26. When the number of individuals is increased to 160, what is the effea on the time taken for metamorphosis to occur? 6 POGIL Activities for High School Biology

29 27. Propose an explanation for why the population size affects the number of weeks before metamor phosis of the tadpoles ocxurs. ^28. The type of competition represented by graph C is referred to as intraspecific competition. What is different about this compared to the competition seen in graph B? Ecological Relationships 7

30 Extension Question 29. An investigation was carried out into comperition between two species of grass, Bromus madritensis and B, ri^dus. Equal numbers of seeds of B. madritensis were sown in a number of different pots. In each pot, an equal number of seeds of B. rig^m was then sown a diflferent number of days after B. madritensis. The results are shown in the graph below. Given that the total dry mass of plant material was the same in each pot, summarize the main conclusions that can be drawn from this investigation. Suggest an explanation for the results when the delay before sowing B. ri^us was 30 days. Percentage contribution of B. madritensis to total dry mass after 45 days Delay before planting B. madritensisi^s^ 8 POGIL Activities for High School Biology

31 Name Quiz Food Web Date True or False? Circle T or F 1. Plants do not benefit from decomposers. T or F 2. Very little photosynthesis takes place in the oceans because of the salt water. T or F 3. Plants make food, and release or produce oxygen in many different types of e n v i r o n m e n t s. T o r F 4. Plants need light to grow. T or F 5. There are no aquatic food webs in New York City. T or F 6. There is more energy available for organisms at the top of the food pyramid than at the b o t t o m. T o r F Multiple Choice: Circle the letter of the best answer 7. All sources of all food can be traced b a c k t o : A. Animals B. Plants C. Bacteria D. Protists 9. Which of the following put important nutrients back into the soil? A. Algae B. Plants C. Decomposers D. The sun 8. Which of the following organisms are not decomposers? A. Fungus B. Bacteria C. Earthworms D. Plants 10. Which of the following statements is true about photosynthesis? A. Plants make their own food using sunlight, carbon dioxide, and water. B. Plants release carbon dioxide as a by-product of photosynthesis. C. Plants use sugar to make food. D. All of the above.

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33 N A M E ^ D A T E p d 0 / E ENERGY PYRAMID % Energy Loss % l e f t Trophic Level

34 Energy Transfer in Living Organisms How does energy move through an organism? Why? The law of conservation of energy states that energy can be neither created nor destroyed; it can only be transferred to another form. In living things energy is transferred as organic matter (molecules of carbohy drate, fets, starch, etc.). But does an organism use all of the energy that is provided by the organic matter available? How is the law of conservation of energy applied to living organisms? Model 1 Food Conversion in a Herbivore Biomass increase/day: 0.64 g Grass ingested/day: 4.0 g 'Egested waste/day: 2.4 g 1. According to Model 1, how many grams of grass does herbivore A eat each day? 2. Refer to Model 1. a. How much did herbivore A grow from eating this grass? b. What term is used to represent growth in Model 1? 3. What is meant by "egested waste" as it is used in Model 1? 4. Is al of the mass of the ingested grass accounted for in the growth and waste of herbivore A? If not, how much is "missing"? Show a mathematical calculation to support your answer. Energy Transfer in Living Organisms 1

35 r 5. In addition to growth and waste production, what else does herbivore As body do with the food it ingests? 6. As cells undergo cellular respiration, what products are produced, and how are they released from the body? 7. Draw an arrow in Model 1 to represent respiration and label it with the appropriate title and mass. Model 2 Energy Efficiency in Two Organisms Respiration/day: kilocalories Respiration/day: 1.6 kilocalories Heat loss/day: Heat loss/day: k i l o c a l o r i e s / > ^ 1. 4 k i l o c a l o r i e s Egested waste/day: 0.33 kilocalories Egested waste/day: 1.25 kilocalories Grass ingested/day: 0.8 kilocalories Grass ingested/day: 5 kilocalories 8. What unit of energy is used in Model 2? 9. Refer to the energy value of the ingested grass in Model 2. a. What is the energy value of the grass eaten by herbivore A each day? b. What is the energy value of the grass eaten by herbivore B each day? c. Which herbivore would you predict to be the larger animal? Explain. 2 POGIL*" Activities for High School Biology

36 10. In Model 2, what are the three ways that the energy taken in by the herbivores is used? 11. For each herbivore calculate the total energy output. U Herbivore A = h. Herbivore B = 12. Does the total amount of energy output for each herbivore add up to the total amount of energy eaten by each herbivore? 13. Use the information given in Model 1. CL What accounts for the diflferences noted in Question 12? k Add labels to Model 2 to show this energy. Read This! Biologists often refer to organic mater by the potential energy that is released when Ae substance under goes a chemical change to make carbon dioxide and water. TTis could occur by burning the organic mat ter or by an organism using the organic matter in celular respiration. 14. According to Model 1, herbivore A eats 4 g of grass per day. Using Model 2, how much potential energy does this represent? 15. According to Model 2, how much energy does herbivore A require for celular respiration each day? 16. Energy lost as either heat to the environment or egested as waste is not considered to be an efficient use by the organism. What percentage of the potential energy of the grass is not efficiently used by herbivore A? 17. What percentage of the potential energy of the grass is not efficiently used by herbivore B? ^18. Do the herbivores have the same efficiency in using die grass toward useful purposes? Explain in two or more complete sentences. Energy Transfer in Living Organisms 3

37 19. Herbivores A and B are eaten by carnivores. a. Which category of energy related to the organisms in Model 2 is direcdy available to the car nivore who eats the herbivores: grass, respiration, biomass or waste? b. What percentage of the original "grass energy" is available to the carnivore if it eats herbivore A? c. What percentage of the original "grass energy" is available to the carnivore if it eats herbivore B? 20. Which herbivore is the more efficient food choice for the carnivore? Why? 4 POGIL Activities for High School Biology

38 Extension Questions 21. Is the egested waste from an organism wasted energy? If not, describe how this energy (organic matter) might be used in a useful way. 22. Insects are poikilothennic ("cold-blooded"), while mammals are homeothemuc ("warm-blooded"). Using this information, explain why rabbits use more of their energy for respiration compared to grasshoppers. 23. Which fiiagram in Model 2 could represent the grasshopper and which could represent the rabbit? Energy Transfer in Living Organisms 5

39 NAME DATE,PD 0/E OWL PELLET LAB This ow! is HUNGRY!! Sketch what you think might end up in his talons

40 What are Owl Pellets? "All you ever wanted to know but were afraid to ask" Owl pelets are masses of bones, teeth, hair, feathers, scales, and insect skeletons. They are produced and regurgitated, not only by owls, but also by hawks, eagles, and other raptors which swallow their prey whole or in large pieces. The soft parts of the prey are dissolved by proteolytic enzymes (protein digesters) and strong acids which occur in high concentrations in the stomachs of raptors. The relatively weak stomach muscles of the bird form the undigested fur, bones, feathers, etc. into wet, slimy pellets. In this process, even the most jfragile bones are usually preserved unbroken. Because the pyloric opening of the stomach into the intestine is narrow, only finely divided materials pass into the intestine. As a result, tmy bones only occasionally pass through the digestive system. Each whole owl pellet usually contains virtually complete skeletons of the animals which the owl ate the night before the pellet was formed. Directions: Use the forceps and probes (and vinyl gloves if you'd like) to separate the owl pellets into parts. Use the laminated Bone ID Sheet to aid in sorting and identifying what your owl ate. Record below. sketch Identify What did your owl eat?

41 SUMMARIZE ENERGY TRANSFER FOR AN OWL Start at the bottom with a plant and continue to the top with the owl. Use any clues from your own pellet and the food web provided. Why do you think organisms at the top of the energy pyramid (top of the food chain) are more likely to become endangered?

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44 Learning-Focused Strategies Notebooi( Teacher Materials 2004 Learning Concepts, Inc. Cause and Effect Ca

45 Succession How do ecosystems develop over time? Why? On May 18, 1980, Mount St. Helens in the state of Washington erupted with the force of a hydrogen bomb. The volcano had been dormant for over 120 years, but now 57 people were dead and forests and lakes were totally destroyed, including nearby Spirit Lake, which became a mud hole. The blast leveled trees in areas over 10 miles from the crater and ash deposits suffocated life on the mountain. However, within weeks, mammals that had taken shelter underground started to reappear in the area, and now, over thirty years later, many areas of the mountain are colonized with a large variety of plant and animal life. How does an area move from a sterile, barren wilderness to one full of life? Model 1 - Primary Succession O o Barren rock from beneath a retreating glacier, or due to a volcanic eruption. Low-growing plants such as mosses, ferns, and lichens begin to colonize. Fast-growng grasses, flow ering plants, and small shrubs b^n to take root. A thin layer of soil develops. Fast-growing trees such as birch and mountain ash form a low forest and shade out lower plants years since colonization began, large, slow-growing trees, such as an oak, become established. Succession

46 1. Refer to Model 1. a. On what type of land does primary succession first begin to occur? b. Does there appear to be any life on the land when primary succession begins? c. Why would most plants such as shrubs and trees find it difficult to grow here? 2. Refer to diagram B in Model 1. a. What are the first organisms (colonizers) on this land? b. Suggest the mechanisms by which the first colonizers arrived on the land. Read This! The first colonizers are referred to as the pioneer commimity. These can include lichens, mosses, ferns, and bacteria all organisms with low nutrient requirements. As they colonize, they break the weathered rock surface, which helps to create the first thin layer of soil. Without soil other plant life cannot be sustained and without plants no animal life can exist. 3. Refer to Model 1. a. Which diagram illustrates a pioneer community? b. What are some of the features of the pioneer community? 4. Notice the colonizers in diagrams C and D are taller and require more nutrients than those in the pioneer community. Considering what you already know about plants and photosynthesis, why might it be a competitive advantage for a plant to be taler? 5. What happens to the pioneer organisms once the new colonizers become established? / 2 POGIL Activities for High School Biology

47 Read This! As the newer colonizers begin to take over, animals will also begin to appear so they can feed on the more diverse food source. The pioneer plants die and decompose and the animals leave behind manure. Both add to the thin soil layer. 6. What eflpect will the addition of animal waste and decayed plant matter have on the soil and land? 7. How will grazing animals help plants to become established? 8. How will the grazing animals prevent or control further colonization by other plants? 9. Using the diagrams in Model 1 as a guide to develop a definition with your group for the term primary succession, as it relates to the colonizing of barren land. Read This! As soil quality and quantity improves, the life forms present in the area undergo a series of changes, each referred to as a serai stage. Eventually a stable climax community is formed. 10. Label the pictures in Model 1 as pioneer community, serai stages, and climax community. 11. Most climax communities are mature forests. What features of mature forest species, such as oak trees, make them able to dominate and compete in the ecosystem? 12. What environmental factors may affect the type of climax community that develops in an ecosystem? Succession 3

48 Model 2 - Secondary Succession ':;0 o;' O O- Established climax community. Forest fire. A;; Plants have been destroyed and animals have fled the burned out area A layer of ash is over the soil. o O X After 3-5 years grasses and low-growing shrubs have colonized the land. After 20 years small trees form young woodland years after the setback event, mature oak woodland is restored. 13. Refer to the diagrams in Model 2. a. What stage of development does diagram A represent? b. What appears to have happened in diagram B? c. What could be two causes of this event? d. What process will begin again after this event has occurred? 14. Can the ecosystem totally recover from this set-back? What evidence is given in Model 2? 4 P O G I L A c t i v i t i e s f o r H i g h S c h o o l B i o l o g y

49 15. What eflpect does an existing soil presence have on the serai stages of secondary succession and the time it takes to return to the climax community compared to primary succession? Give your answer in complete sentences and justify your reasoning. 16. Why is the tide of Model 2 Secondary Succession rather than Primary Succession? 17. Consider each event below and determine if the recovery process for the environment will happen by primary succession or secondary succession. a. Melting, receding glaciers. b Lo^ng a wooded area. c. Major flooding of a creek bed. d. Volcanic eruption with lava flow. 18. Are these destructive methods always natural? Explain your answer. Human activity may alter or "deflect" the natural course of succession, which leads to a change in the climax community. An example of a human activity that deflects succession would be grass mowing. The climax community that develops from a deflected succession is called a plagiodimax community. Surest some other human actions that may lead to plagioclimax communities. Succession 5