1. The graph below shows the relationship between temperature and precipitation for six major ecosystems in North America.

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1 1. The graph below shows the relationship between temperature and precipitation for six major ecosystems in North America. Some scientists predict that global climate change could cause temperatures in North America to rise by as much as 5 o C in the next 100 years. Based on the information in the graph, which statement describes how areas that are currently occupied by northern coniferous forests will most likely be affected by the climate change predicted by these scientists? (A) Much of the area occupied by northern coniferous forests will be transformed into temperate broadleaf forests and the biodiversity of coniferous forest species will decrease. This answer suggests the student understands that a 5 o C change in average temperature will allow temperate broadleaf forests to become more successful in the areas once occupied by northern coniferous forest ecosystems, and that the biodiversity of northern coniferous forest species will decrease as a result of lost habitat. (B) Much of the area occupied by northern coniferous forests will be transformed into deserts and the biodiversity will decrease because of the harsh desert conditions. This answer suggests the student may understand that the biodiversity in desert ecosystems is low due to harsh conditions, but does not understand that a change of 5 o C is not likely to result in a desert since the scientists did not predict any changes in precipitation. Page 1 of 7

2 (C) Much of the area occupied by northern coniferous forests will be transformed into tropical forests and the biodiversity will increase because tropical forests have the highest levels of biodiversity. This answer suggests the student may understand that tropical forest ecosystems have the highest biodiversity of all ecosystems, but does not understand that a change of 5 o C is not likely to cause tropical forests to develop in areas once occupied by coniferous forests because that would require a change of more than 5 o C and an increase in average precipitation. (D) Much of the area occupied by northern coniferous forests will be transformed into temperate grasslands and the biodiversity of coniferous forest species will remain unchanged. This answer suggests the student may understand that increases in temperature could transform coniferous forest ecosystems into temperate grasslands, but does not understand that this change is likely to affect the biodiversity of coniferous forest species. 2. Opossum shrimp were introduced into the Flathead Lake watershed in the early 1980s. It was hoped that the introduction of the shrimp would lead to an increase in the salmon population, and because bald eagles feed on salmon, an increase in the bald eagle population as well. The graph below shows the populations of kokanee salmon, bald eagles, lake trout, and opossum shrimp in the Flathead Lake watershed over a 26-year period. Based on the information in the graph, which conclusion best explains the effect of the shrimp on Page 2 of 7

3 the Flathead Lake watershed? (A) The opossum shrimp and lake trout populations increased because the kokanee salmon and bald eagle populations decreased, which caused more resources to become available for the opossum shrimp and the lake trout. This answer suggests the student understands that the kokanee salmon and bald eagle populations decreased and that the opossum shrimp and lake trout populations increased, but does not understand that the decline in the kokanee salmon and bald eagle populations was caused by the lake trout outcompeting the kokanee salmon for resources. (B) The opossum shrimp population increased because the opossum shrimp is an invasive species with no predators and was able to outcompete other aquatic invertebrates for resources, which decreased resources for all other predatory species. This answer suggests the student understands that the opossum shrimp is an invasive species, but does not understand that the lake trout is a predator of the opossum shrimp, as evidenced by the growth in the lake trout population shortly after the arrival of the opossum shrimp. (C) The bald eagle population decreased because the opossum shrimp are a major food source for lake trout, and the lake trout were able to outcompete the kokanee salmon for resources. This answer suggests the student understands that the graph shows a predator-prey relationship between the lake trout and the opossum shrimp, that a decreasing kokanee salmon population suggests that the kokanee salmon are probably not feeding on opossum shrimp, and that the lake trout were able to outcompete the kokanee salmon for resources. (D) The lake trout and kokanee salmon populations decreased because the opossum shrimp were able to directly outcompete the lake trout and kokanee salmon for resources. This answer suggests the student understands that the graph shows some species declining after the introduction of the opossum shrimp, but does not understand that the lake trout benefitted from the opossum shrimp and that the kokanee salmon and bald eagles did not because the lake trout were able to eat the opossum shrimp and the salmon were not. Page 3 of 7

4 3. The diagrams below show the age-structure pyramids for two different countries. Which statement describes what is most likely causing each country to have the age structures shown in the diagrams? (A) Country 1 is experiencing rapid population growth because the majority of the population is under 20, and country 2 is experiencing negative population growth because the majority of the population is past the reproductive prime. This answer suggests the student may understand that a broad-based age-structure pyramid often indicates a rapidly growing population and a narrow-based age-structure pyramid often indicates negative population growth, but does not understand that the population of country 2 is relatively stable because the birth rate is about equal to the death rate. (B) Country 1 will experience rapid population growth in about 20 years because the majority of the population will begin reproducing, and country 2 will most likely experience negative population growth in about 20 years because a significant percentage of the population will be very old. Page 4 of 7

5 This answer suggests the student may understand that a broad-based age-structure pyramid often signifies an increase in future population as children reach their reproductive years, but does not understand that country 1 is currently experiencing population growth, or that the population of country 2 is stable because the birth rate and the death rate are nearly equal. (C) Country 1 is experiencing rapid population growth because it has a high birth rate compared to its death rate, and country 2 has a stable population because the birth rate and death rate are nearly equal to one another. This answer suggests the student understands how to make predictions about populations based on age-structure pyramids, that the population of country 1 is most likely growing due to the high birth rate relative to the death rate, and that the population of country 2 is most likely stable due to the nearly equal birth rate and death rate. (D) Country 1 is decreasing in size because many individuals in the older age ranges have died, and country 2 has a growing population because it has more people in each age class who are surviving. This answer suggests the student may understand that a broad-based age-structure pyramid could indicate a high death rate, but does not understand that the broad-based pyramid can also indicate a high birth rate relative to death rate in a growing population, or that the column shape of the population in country 2 indicates that it is a stable population. Page 5 of 7

6 4. Species richness is defined as the number of different species in an area. A scientist determines the species richness and the relative abundance of trees in woodlot X and woodlot Y. The table below shows the percent of each species of tree found in the two woodlots. Which statement best predicts how the species richness, species diversity, and relative abundance will be affected if all the red maples are destroyed by parasites? (A) Woodlot X will have a greater species richness than woodlot Y, but woodlot Y will have a greater relative abundance; however, further analysis will be needed to determine which woodlot has the greatest species diversity. This answer suggests the student may understand that two areas with different species richness and relative abundance need more mathematical analysis to determine species diversity, but does not understand that woodlot Y has a greater species richness than woodlot X, or that woodlot X has a greater relative abundance than woodlot Y. (B) Both woodlots will have the same relative abundance, but woodlot Y will have a greater species richness and therefore a greater species diversity than woodlot X. This answer suggests the student may understand that if two areas have an equal relative abundance, then the area with a greater species richness will have the greater species diversity, but does not understand that woodlot Y has a greater species richness and woodlot X has a greater relative abundance, so more analysis is needed to determine which woodlot has a greater species diversity. (C) Both woodlots will have the same species richness, but woodlot X will have a greater relative abundance and therefore a greater species diversity than woodlot Y. Page 6 of 7

7 This answer suggests the student may understand that woodlot X has a greater relative abundance, but does not understand that woodlot Y has a greater species richness, so more analysis is needed to determine which has a greater species diversity. (D) Woodlot Y will have a greater species richness than woodlot X, but woodlot X will have a greater relative abundance; however, further analysis will be needed to determine which woodlot has the greatest species diversity. This answer suggests the student understands how to analyze data for species richness (the total number of different species) and relative abundance (the proportion of each species) and that further mathematical analysis is required in order to determine which area has the greater species diversity based on the number of trees remaining in each woodlot. Page 7 of 7