Unit 8 Review

b. c. d. 5. In the Arctic Ocean, the predominant primary producers are phytoplankton. Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In years when there is more open water (less ice coverage), there are more zooplankton and fish than in years with less open water (more ice coverage). Based on the graph above, the difference is most likely because (read the question carefully, the zooplankton eat the phytoplankton, so they're not the producers but are the consumers) a. when there is less open water, light is blocked from the zooplankton, so they cannot produce as much food for the fish b. when there is more open water, the temperature is warmer, so the zooplankton and fish populations increase in size c. the ice blocks the light, so in years with more ice coverage, there is less photosynthesis by the phytoplankton d. the ice increases the light available for photosynthesis, so primary production increases and zooplankton populations increase in size Use the following information to answer question 6. An experiment to measure the rate of respiration in crickets and mice at 10°C and 25°C was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O 2 consumed per gram of organism over several five- minute trials and the following data were obtained. Organism Temperature (°C) Average respiration (mL O 2 /g/min) Mouse 10 0.0518 Mouse 25 0.0321 Cricket 10 0.0013 Cricket 25 0.0038 6. According to the data, the crickets at 25°C have greater oxygen consumption per gram of

a. The amount of biomass in the first trophic level decreased. b. The amount of biomass in the second trophic level decreased. c. The amount of energy available to producers in the lake increased. d. The amount of energy available to consumers in the lake increased (phytoplankton biomass increased which means there is more energy available for the consumerism the higher trophic levels) 13. Thrips are insects that feed on rose pollen. Scientists noted that the thrips population increased in the spring and decreased dramatically during the summer. The researchers hypothesized that food abundance was the limiting factor for the population. Which of the following types of data would be most useful for the scientists to collect at regular intervals on a designated test plot of rose plants? a. Amount of sunlight (hours/day) b. Mean temperature (°C) c. Density of rose pollen produced (g/m 2 ) d. Amount of pollen produced by each flower (g/flower) 14. The diagram below shows the progression of ecological events after a fire in a particular ecosystem. Based on the diagram, which of the following best explains why the oak trees are later replaced by other trees? a. Eventually the other trees grow taller than the oak trees and form a dense canopy that shades the understory. b. Oak trees alter the pH of the soil, making the forest better suited for shrubs and other trees. c. Roots of shrubs proliferate in the soil of the forest and prevent the oak trees from obtaining water. d. Oak trees succumb to environmental pollutants more readily than do either the shrubs or the other trees. Use the following information to answer questions 15-17. The figures below show the changes in populations of two species of flour beetles, Tribolium confusum (Figure I) and Tribolium castaneum (Figure II), in cultures without parasites (o) and in cultures infected with a parasite (•). Each data point represents the mean population size from ten culture dishes of equal size and food content.

24. A cheetah urinates on a tree. Which of the following describes the purpose of this signal? a. indicate dominance b. establish territory c. find food d. ensure reproductive success 25. Which of the following best describes the body temperature regulation for an alligator? a. ectotherm that maintains body temperature through metabolism b. ectotherm that maintains body temperature through behaviors c. endotherm that maintains body temperature through metabolism d. endotherm that maintains body temperature through behaviors 26. Which of the following best describes the relationship between metabolic rate per unit body mass and the size of multicellular organisms? a. the smaller the organism, the higher the metabolic rate b. the larger the organism, the higher the metabolic rate c. the higher the surface area to volume ratio of the cells, the higher the metabolic rate d. the lower the surface area to volume ratio of the cells, the higher the metabolic rate 27. Which of the following best describes the changes to the trophic structure with a decrease in plant population? a. increase in primary and secondary consumers b. decrease in primary and secondary consumers c. decrease in secondary consumer, increase in primary consumer d. increase in secondary consumer, decrease in primary consumer 28. Which of the following describes the energy resource used by chemosynthetic organisms? a. small inorganic molecules preset in their environment b. organic molecules broken down by the mitochondria c. photons absorbed by chlorophyll in the chloroplast d. air movement turns hairs on organismal surface 29. Which of the following is a material that heterotrophs are unable to metabolize? a. carbohydrates b. nucleic acids c. lipids d. proteins 30. In a population of 100 individuals, 20 individuals are born and there are 5 deaths. What is the r value? Recall: r = per capita growth rate of population a. .05 b. .15 c. .20 d. .25 31. If the population size is 100 individuals and there is a r value of 0.3, what is dN/dt? Recall: dN/dt = rN a. 10 b. 15 c. 30 d. 60 32. As the population size approaches carrying capacity, dN/dt... a. increases steadily b. increases slowly c. decreases slowly d. decreases steadily

The deletion of a base pair would cause a frameshift mutation which would result in either decreased or no production of the IAA because the frameshift mutation would lead to a nonfunctional protein, enzyme TRP-T because the mRNA would not be translated correctly. (c) Explain one feedback mechanism by which a cell could prevent production of too much IAA without limiting I3PA production. Negative feedback could prevent production of too much IAA by increasing the amounts of IAA produced. This would inhibit the enzyme YUC production pathway. (d) Rhizobacteria are a group of bacteria that live in nodules on plant roots. Rhizobacteria can produce IAA and convert atmospheric nitrogen into forms that can be used by plants. Plants release carbon-containing molecules into the nodules. Based on this information, identify the most likely ecological relationship between plants and rhizobacteria. Describe ONE advantage to the bacteria of producing IAA. Mutualism. Bacteria receive carbon containing molecules from the plants and it would increase the amount of nodules. (e) A researcher removed a plant nodule and identified several “cheater” rhizobacteria that do not produce IAA or fix nitrogen. Describe the evolutionary advantage of being a bacterial cheater in a population composed predominantly of non-cheater bacteria. Plants can adjust the amount of carbon-containing molecules released into nodules in response to the amount of nitrogen fixed in the nodule. Predict the change in the bacterial population that would cause the plant to reduce the amount of carbon-containing molecules provided to the nodule. The advantage to being a bacterial cheater is that the bacteria receive carbon containing molecules without having to fix nitrogen. They are getting the energy that they need to be able to reproduce. Decreasing the amount of non cheater bacteria would reduce the amount of carbon containing molecules provided to the nodule. 2. A student studying two different aquatic, plant-eating, unicellular protist species (species A and B) designed an experiment to investigate the ecological relationship between the two species (Table 1). In treatment group I, the student placed 10 individuals of species A into a container with liquid growth medium and 10 individuals of species B into a separate container with an equal amount of the same liquid growth medium. In treatment group II, the student placed 5 individuals of each species into a single container with the liquid growth medium. The student then maintained the containers under the same environmental conditions and recorded the number of individuals in each population at various time points. The results are shown in Table 2.

* the cuckoos were removed from the nest containing warblers and cuckoos (group 2) (c) Identify the symbiotic relationship that exists between the cuckoo and the warbler in the presence of predators. Mutualism because both organisms benefit. 4. The table below shows how much each organism in an aquatic ecosystem relies on various food sources. The rows represent the organisms in the ecosystem, and the columns represent the food source. The percentages indicate the proportional dietary composition of each organism. High percentages indicate strong dependence of an organism on a food source. (a) Based on the food sources indicated in the data table, construct a food web in the template below. Write the organism names on the appropriate lines AND draw the arrows necessary to indicate the energy flow between organisms in the ecosystem.

There are 2 degrees of freedom so using a P value of 0.05 the critical value is 5.99. The calculated Chi square value is 48.9 which is greater than the critical value, so the null hypothesis can be rejected. (e) Briefly propose a model that describes how environmental cues affect the behavior of the flies in the choice chamber. In increased temperatures, the fruit flies will move about randomly more than they would in normal temperatures. Once they encounter the glucose, they recognize it as a food source and will remain by it for a longer period of time. PART (C): CHI-SQUARE CALCULATIONS Null Hypothesis: The type of banana will have no effect on the position of the flies and the flies will be evenly distributed among the three different parts of the choice chambers. Observed (o) Expected (e) (o-e) 2 /e End with ripe banana 45 20 31.25 Middle 3 20 14.45 End with unripe banana 12 20 3.2 Total 60 60 48.9