The Moths and the Trees #1 Answer Key

Transcription

1 The Moths and the Trees # Answer Key This task provides practice for the following strands:. Systems 2. Application 3. Ecosystems 4. Evolution/Genetics Moths and Trees # Example Page

2 Moths and Trees Task Matrix Items Systems Inquiry Application Cell Processes LS Ecosystems LS2 Evolution/ Genetics LS3 a SYSB(4) LS2E(2) b SYSB(4) LS2B() c SYSB(4) LS2A(3) d SYSB(4) LS2A(3) 2a 2b 2c LS3E() LS3B(2) LS3A(4) *3a APPE() 3b APPC(2) 4a **4b 4c SYSC() SYSC(2) SYSA(2) possible 8*** *** 4 *This item was piloted 20, and operational in 202 and 203. The item has been edited to more closely model other COE tasks. **This item was piloted in 20. The item has been edited to more closely model other COE tasks. ***Scores generated from crossed items such as item may only be counted in a single strand, either Systems or Ecosystems (LS2) but not both. Moths and Trees # Example Page 2

3 Performance Description Item number: Cognitive Complexity: 2 (Page of 2) A 4-point response demonstrates the student understands: Content Standard LS2A: Matter cycles and energy flows through living and nonliving components in ecosystems. The transfer of matter and energy is important for maintaining the health and sustainability of an ecosystem. Item Specification 3: Describe the cycle of nitrogen through ecosystems. Content Standard LS2B: Living organisms have the capacity to produce very large populations. Population density is the number of individuals of a particular population living in a given amount of space. Item Specification : Describe conditions necessary for populations to increase rapidly. Content Standard LS2E: Interrelationships of organisms may generate ecosystems that are stable for hundreds or thousands of years. Biodiversity refers to the different kinds of organisms in specific ecosystems or on the planet as a whole. Item Specification 2: Describe interrelationships of organisms that affect the stability of a given ecosystem SYSB: Systems thinking can be especially useful in analyzing complex situations. To be useful, a system needs to be specified as clearly as possible. Item Specifications 4: Describe how a given system functions with respect to other systems. Item and example response LS2E(2)/SYSB(4) a) The response describes how moths and/or birds help to maintain a stable Douglas fir tree population by: Describing an interaction of moths and/or birds with the Douglas fir tree population Describing how that interaction helps to maintain a stable Douglas fir tree population. Birds eat the moth larvae. Fewer larvae results in fewer trees being eaten so more trees survive. Moth larvae eat some bigger trees. Fewer needles on those trees allow more sunlight to reach Douglas fir seedlings so more new trees grow. Moths attract birds to the trees/birds make their nests in the Douglas fir trees. Birds spread the seeds so trees can grow in other locations. Moth larvae eat the needles and keep the Douglas fir population from overpopulating the ecosystem. Moths and Trees # Example Page 3

4 Item and example response Item number: Cognitive Complexity: 2 (Page 2 of 2) LS2B()/SYSB(4) b) The response describes one change to the forest ecosystem that could allow the population of the moths to increase rapidly by: Identifying one change to the forest ecosystem Describing how that change could cause the population of moths to increase. A new predator/disease of birds moves in so there are fewer birds to eat the larvae. Lots of rainfall allows increased growth of Douglas fir trees so there is a bigger food source for the larvae. Moths develop resistance to a disease so more moths live to reproduce. A mild winter allows more moths/larvae to survive and reproduce in the spring. A competing species of insect dies off/leaves the area leaving more food/habitat for moths. LS2A(3)/SYSB(4) c) The response describes how nitrogen from the atmosphere can become part of molecules in a tree Nitrogen from air is changed by bacteria in soil to a form trees can absorb through their roots. Nitrogen in air is changed by lightning and carried by rain to soil to be taken in by trees. Nitrogen from air can be converted into fertilizer and spread on soil to get into the tree through the roots. LS2A(3)/SYSB(4) d) The response describes how nitrogen from trees can become part of molecules in a moth. Moth and/or larvae get nitrogen by eating organisms that ate plants Moth and/or larvae get nitrogen by eating plants/needles. A 3-point response demonstrates the student has partial understanding of the Content Standard. A 2-point response demonstrates the student has limited understanding of the Content Standard. A -point response demonstrates the student has very little understanding of the Content Standard. A 0-point response demonstrates the student has almost no understanding of the Content Standard. Moths and Trees # Example Page 4

5 Performance Description Item number: 2 Cognitive Complexity: 2 (page of 2) A 4-point response demonstrates the student understands: Content Standard LS3A: Biological evolution is due to: () genetic variability of offspring due to mutations and genetic recombination, (2) the potential for a species to increase its numbers, (3) a finite supply of resources, and (4) natural selection by the environment for those offspring better able to survive and produce offspring. Item Specification 4: Describe how environmental pressure on a population drives natural selection (e.g., warming climate causes extinction of species not able to adapt). Content Standard LS3B: Random changes in the genetic makeup of cells and organisms (mutations) can cause changes in their physical characteristics or behaviors. If the genetic mutations occur in eggs or sperm cells, the changes will be inherited by offspring. While many of these changes will be harmful, a small minority may allow the offspring to better survive and reproduce. Item Specification 2: Describe the molecular processes and/or environmental factors by which mutations can occur. Content Standard LS3E: Biological classifications are based on how organisms are related, reflecting their evolutionary history. Scientists infer relationships from physiological traits, genetic information, and the ability of two organisms to produce fertile offspring. Item Specification : Describe that scientists infer the degree of evolutionary relationship among organisms using physiological traits, genetic information, and/or the ability of two organisms to produce fertile offspring. Item and example response LS3E() a) The response describes one type of evidence that could lead scientists to conclude that there is a close evolutionary relationship between the charcoal-brown tussock moth and the white-marked tussock moth. The two moths have similar genes/patterns in the DNA. The same proteins are made in both moths. When a brown moth and white-marked moth are mated, fertile offspring are produced. Charcoal brown moths and white-marked moths have similarly shaped wings. The pattern of development from egg to larvae to moth is the same time/stages. Moths and Trees # Example Page 5

6 Item and example response Item number: 2 Cognitive Complexity: 2 (page 2 of 2) LS3B(2) b) The response describes a molecular process that can result in a mutation. An extra nucleotide/base/a,c,g,t gets inserted into the DNA An A,C,G, or T could get deleted from the chromosome. A nitrogenous base could be swapped for a different base in the DNA. Two bases could trade places in the gene. Radiation can break bonds in the gene. LS3A(4) c) The response describes two ways environmental changes could affect a population of tussock moths by: Identifying two environmental changes that could affect the tussock moth population For each environmental change, predicting the effect of natural selection on a trait in the population and giving a reason for each prediction. Warmer temperatures cause only larvae that can stand the heat to survive. The genes to withstand higher temperatures are passed on by the surviving larvae. Colder temperatures keep some females from attracting mates because the pheromone doesn t travel far. The surviving population will be the moths that produce more pheromone/stronger pheromones. Acid rain can harm cocoons. If some of the moths are able to make cocoons that resist the acid, those moths will be the ones that survive and reproduce. A drought can cause less tree growth, the food for larvae. Larvae that are able to mature with less food from will reproduce and pass on that trait. A disease could be introduced to the ecosystem. Moths resistant to the disease would survive and reproduce. Over time, most moths in the population would be resistant. An increase in rainfall could cause different plant types to grow. Moths with wing patterns that are better camouflaged by the new plant types could hide from predators and be able to pass on their genes for that wing pattern. Note: Responses identifying one environmental change, predicting the effect of natural selection on a trait in the population and giving a reason for that prediction may be credited one point. Performance Description 2 A 3-point response demonstrates the student has partial understanding of the Content Standards. A 2-point response demonstrates the student has limited understanding of the Content Standards. A -point response demonstrates the student has very little understanding of the Content Standards. A 0-point response demonstrates the student has almost no understanding of the Content Standards. Moths and Trees # Example Page 6

7 Performance Description Item number: 3 Cognitive Complexity: 2 (page of 2) A 4-point response demonstrates the student understands: Content Standard APPC: Choosing the best solution involves comparing alternatives with respect to criteria and constraints, then building and testing a model or other representation of the final design. Item Specification 2: Describe a method for testing the solution(s) given a problem that can be solved using a technological design process and possible solution(s). Content Standard APPE: Perfect solutions do not exist. All technological solutions involve trade-offs in which decisions to include more of one quality means less of another. All solutions involve consequences, some intended, others not. Item Specification : Describe trade-offs and/or unintended consequences for one or more given solution(s) to a given technological design problem. Item and example response APPE() a) The response describes two possible unintended consequences of using pesticides to remove the tussock moth by: Describing two unintended consequences of using pesticides to remove the tussock moth Describing how each unintended consequence could affect another organism in the forest ecosystem. Describes unintended consequence Describes change in another organism Water is polluted/pesticide gets into water Air is polluted by the pesticide Pesticide kills insects other than tussock moth Some plants are harmed by the pesticide Fish/aquatic insects/aquatic plants are sick/killed Other insects/birds/animals get sick/killed There is less food for the predators of those other insects Less food/habitat is available for animals who use those plants The pesticide in small organisms kills/harms predators of those organisms Biomagnification/pesticide builds up in food chain Trees grow bigger and produce more Smaller plants are not able to grow in the shade shade since no moths are eating them Note: Responses describing one unintended consequence of using pesticides and describing how that unintended consequence would cause a change in another part of the forest ecosystem may be credited one point. 2 Moths and Trees # Example Page 7

8 Item and example response Item number: 3 Cognitive Complexity: 2 (page 2 of 2) APPC(2) b) The response describes a way to test whether Solution A or Solution B would be a more effective solution to reducing tussock moth populations on Douglas fir trees on a tree farm by describing: A method for testing each solution The data to be collected to determine whether Solution A or Solution B is more effective for reducing the tussock moth population. Use two greenhouses. Place one Douglas fir tree with tussock moth cocoons in a greenhouse. Place another Douglas fir tree with tussock moth cocoons in the other greenhouse. Spray the first tree with the chemical pesticide. Spray the second tree with the bacteria. Once a week count the number of larvae on each tree. Choose two tree farms. On one tree farm spray the chemical pesticide. On the other tree farm spray the bacteria. At each tree farm randomly choose five trees and mark them. At 0:00 a.m. on each Monday count the number of tussock moth larvae on each marked tree from each farm. Repeat counts for eight weeks. Divide a tree farm into two halves. Use sprinklers that spray bacteria on one half. Spray the other half with pesticides from airplanes. After one week see which half has the least number of moths. Note: Responses describing a method for testing each solution with a vague or incomplete description of the data to be collected OR describing the data needed to determine which solution is more effective with a vague or incomplete description of the method for testing each solution may be credited one point. 2 A 3-point response demonstrates the student has partial understanding of the Content Standard. A 2-point response demonstrates the student has limited understanding of the Content Standard. A -point response demonstrates the student has very little understanding of the Content Standard. A 0-point response demonstrates the student has almost no understanding of the Content Standard. Moths and Trees # Example Page 8

9 Item number: 4 Cognitive Complexity: 2 (page of 2) Performance Description A 4-point response demonstrates the student understands: Content Standard SYSA: Feedback is a process in which the output of a system provides information used to regulate the operation of the system. Positive feedback increases the disturbance to a system. Negative feedback reduces the disturbance to a system. Item Specification 2: Determine whether a given system involves positive feedback or negative feedback. Content Standard SYSC: In complex systems, entirely new and unpredictable properties may emerge. Consequently, modeling a complex system in sufficient detail to make reliable predictions may not be possible. Item Specification and 2:. Given a model of a complex system that is lacking sufficient detail to make reliable predictions about that system, describe inadequacies of the model. 2. Predict the possible consequences of a change in a given complex system and/or describe why a simplified model may not be able to reliably predict those consequences. Item and example response SYSC() a) The response describes two ways the greenhouse model might be unable to reliably predict the effects of tussock moths on the forest ecosystem by: Identifying two differences between the model and the forest ecosystem other than temperatures Describing how each difference can prevent scientists from making accurate predictions about the effects of tussock moths on forest ecosystems Identify differences: There are many more types of trees in the forest than in the greenhouse Humidity/rainfall/acid rain/forest fires is much more varied in the forest Many more interactions between animals/other organisms in the forest Moths can t escape the greenhouse. Prevents reliable predictions: Scientists won t know the variety of different trees that tussock moths can eat and damage Populations of moths fluctuate more in the forest, so moths can eat more or less needles at different times. Scientists can t predict how populations of moth competitors are affected by moth populations. The moth population in the forest will grow more slowly with predators and more trees will survive. Moths in the forest can move in and out. More tree damage than what really happens will be shown in the greenhouse. The moths in the forest have a greater genetic variation, increasing the biodiversity of the forest. Note: Responses identifying only one difference between the model and the forest ecosystem other than temperatures and describing how that difference can prevent scientists from making accurate predictions about the effects of tussock moths on forest ecosystems may be credited one point. 2 Moths and Trees # Example Page 9

10 Item and example response Item number: 4 Cognitive Complexity: 2 (page 2 of 2) SYSC(2) The response describes one way the greenhouse model may lead to unreliable predictions about the effects of temperature changes over time on the tree population in a forest ecosystem. The greenhouse model will not contain diseases/new pests/new competing plants that might affect trees at different temperatures. Other changes related to temperature in the ecosystem like amount of rain could change the tree population but would not occur in the greenhouse. The greenhouse model may not last long enough to observe changes in the trees that take a long time to show up. SYSA(2) b) The response describes whether this cycle represents positive or negative feedback by: Identifying whether the cycle represents positive or negative feedback Describing the reason for the choice. Negative, because photosynthesis slows when carbon dioxide decreases, allowing carbon dioxide to go back up Negative, photosynthesis increases causing CO 2 to decrease and vice versa Negative, because the system keeps balancing itself/staying in equilibrium A 3-point response demonstrates the student has partial understanding of the Content Standards. A 2-point response demonstrates the student has limited understanding of the Content Standards. A -point response demonstrates the student has very little understanding of the Content Standards. A 0-point response demonstrates the student has almost no understanding of the Content Standards. Moths and Trees # Example Page 0