Bio20C W13 Final - Bio 20C Winter 2013 Final Exam Name/SID...

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Unformatted text preview: Bio 20C Winter 2013 Final Exam Name/SID Read the following paragraph and then answer the questions that follow: Prairie dogs are common inhabitants of the North American plains. Prairie dogs clip and eat grasses around their colony, called a coterie. This grazing promotes the growth of certain types of plants and increases the nitrogen concentration and nutritional value of the new growth. This is why antelope, and bison often prefer to forage within prairie dog colonies. Prairie dogs dig to find food and to build deep burrows underground. This activity allows water to penetrate deeper into the ground and enhances soil structure. The moon as it passes raises and lowers the underground water table like tides and the earth breathes, through the many fissures and tubes they create. Old burrows are often used a shelters by other animals such as black footed ferrets. Prairie dogs must watch for predators and clipping grasses helps them spot threats Often a coterie has a sentinel set apart from the other members who will alert the group with a distinct alarm when a predator approaches. These calls e can be quite complex, consisting of a combination of body motions and vocalizations, and there are distinct alarms for different predators such as hawks or coyotes. When prairie dogs are removed from the landscape, the soil becomes less fertile and drier and many of their predators decline as well. What biome does this system occur in? (2 pts) Temperate Grassland What prevents trees from being able to grow here? (2pts) Low precipitation For each of the following species pairs, indicate what type of interaction occurs between them in the above described scenario but drawing arrows with the appropriate fitness effect each species has on the other. Make sure to indicate direct interactions with a solid arrow and indirect interactions with a dotted arrow. 8 pts (1 Prairie dogs grasses ) (2 coyote prairie dog) Consumption consumption (3 bison prairie dog) (4 prairie dog Commensalism black footed ferret) Commensalism What general type of behavior describes the body motions and vocalizations used in warning calls? 2 pts Communication via auditory & visual cues What evidence if any is there that this behavior has been modified by learning? (2 pts) There are distinct calls and rituals for different types of predators. Now consider the data on the left showing the rates of warning calls as a function of the sentinels relationship to the members of the coterie: What behavior is suggested by the data? (2 pts) Altruism via kin selection What is hamilton’s rule and how is this data supported by it? (4 pts) b*r>c Benefit x relatedness> cost Bar 3 shows that the more offspring in coterie the more likely the indavidual sounded the alarm. Cactus finches are endemic to several islands in the Galapagos whose diet includes both seeds and nectar from the flowers of the cactus finch. On islands where there are bees present, the percentage of diet made up of nectar is significantly lower than on those islands where bees are absent (see graph). A species of hoverfly with similar yellow and black coloration patterns is found on several of the islands that have bees present as well. What type of interspecifc interaction are bees and finches engaged in? (2pts) Competition via interference (possible) On which type of island (bees or no bees) do finches occupy a greater portion of their fundamental niche? (2 pts) No bees What does this suggest about the type of interaction you listed in the first question? (2 pts) Asymmetric.. This suggests that bees are better at getting the food that bees want; so birds live in areas without be On islands with bees, all species of bees have similar coloration patterns. What type of mimicry does this represent? (2 pts) Mullerian What term would desbribe this type of coloration? (2 pts) Aposematism What term best describes the resemblance of hoverflies to bees? (2 pts) batesian mimicry. What would you expect the abundance of hoverflies to be relative to that of bees and why? (4 pts) Hoverflies are present where bees are present due to the fact that predators mistake the hoverflies as bees so they are less likely to be eaten. This is a form of batesian mimicry. Finches on islands with bees are more likely to avoid feeding on nectar after they have experienced a sting from a bee. What type of learning does this represent? (2 pts) Mistake based learning Four islands have nectar feeding bees found on them all are roughly the same distance from the mainland but they are all different sizes ranging from small to large. Which island would you expect to find the most species of bees and why? (4 pts) The larger island you would expect to find the most species of bees due to the fact the island has more room to carry more species before hitting an equilibrium of diversity and extinction. Wandering albatross nest on subAntarctic islands throughout the southern oceans. Nest are constructed in rocky level areas and each bird maintains a buffer zone around their nest. Females typically lay 1-2 eggs in the early summer each year and breed for 15-20 years. Chicks learn to recognize their parents in the first 48 hrs after hatching and this process is irreversible. Juveniles are fledged after about 2 months and spend the first 9 years of their lives flying around the southern ocean in search of food never or rarely spending any time  land. When mature they return directly to their birth island to mate, no matter where they may on be located at the time. What type of breeding strategy do these albatross demonstrate? (2 pts) seasonal Iteroparity What type of dispersion do the birds in the colony demonstrate? (2 pts) Uniform What behavior do chicks demonstrate right after hatching? (2 pts) Imprinting In which biome do juveniles spend the first 9 years of their life in? (2 pts) Oceanic What two factors play the proportionally largest role in regulating productivity in this biome? (4 pts) Nutrients Sunlight What type of orientation do these birds demonstrate when returning to their nesting islands and what specifically suggests this? (4pts) Bicoordinate navigation Now consisder the data on the left on the growth of a nesting population on a newly colonized island. What type of growth does this population demonstrate? (2 pts) Logistic Growth What term would apply to the value 1110 in year 8 2pts Carrying Capacity Give the simplest expression possible for r using the values provided for the following time intervals Years 4-5 (2 pts) 800=400eˆ(r(1)) Years 6-7 (2 pts) 1100=1000eˆ(r(1)) What term would best apply to factors that influence the population growth of this colony Between years 1-3: (2 pts) density independent Between years 6-8: (2 pts) density dependent Albatross demonstrate a type II survivorship curve. In the space below, sketch what this would look like making sure to properly label each axis. (4 pts) log survivorship Bonus Questions: Age What phase of a biogechemcial cycle does CO2 in the atmosphere represent? chemical What is the term for a primary consumer in a decomposing food web? detritivores Read the following paragraph and then answer the questions that follow: Mature tropical rainforest are characterized by towering broadleaf evergreen trees, an open interior, and virtually no ground growth. A common event in the tropical rainforest is the fall of an emergent tree, usually during a tropical thunderstorm. When one of these giants—laden with lianas connected to neighboring trees—falls, it takes out a sizeable portion of the canopy. This hole in the canopy is known as a "light gap" because direct sunlight reaches the floor in contrast to the usual 1-5 percent under full canopy conditions. The light gap is rapidly colonized by fast growing plants like balsa and bamboo, followed later by shrubby plants like gingers and bananas, whose bark and leaves have poor chemical protection and are subject to infection and infestation by insects. Generally, these species flower rapidly and produce numerous fruits, but are soon overtaken by the hardier, better adapted hardwood trees which fill in the gap in the canopy. As a result of the increased light and abundance of fruits produced by gap colonists, light gaps are areas of increased animal activity. Carnivorous animals follow the herbivorous animals that are attracted to the fruiting plants. Also, there are hundreds of hardwood tree saplings waiting for the opportunity to take the place of the fallen tree. When the saplings are touched by direct sunlight, they are stimulated to grow rapidly. Each sapling seeks to become the first to reach the canopy, since those that do not slowly perish under the shade of the newly formed canopy. Characterize the following characteristics of this biome using one of the following terms: (4 pts) Terms: very high, high, moderate, low, very low Characteristics: Average annual temperature: High Average annual precipitation: Very high Variability in annual temperature: Low Variability in annual precipitation: High Briefly explain why this biome has the avg annual precipitation you described above: (2 pts) It is very hot and humid, so the hot air rises collecting moisture and then it rains a lot. What type of succession describes the formation and development of light gaps? (2 pts) Secondary What organisms described (and written in italics) above would best respresent: (3 pts) Early successional species balsa & bamboo Mid successional species Ginger and bananas Apex community species Herbivorous and carnivorous species What trait described above caused you to select in the previous question: (4 pts) The early successional species you chose Fast growing plants, these The apex community species you chose Better competitors, low dispersal Describe two different successional interactions that have occurred in this scenario making sure to name the type of successional interaction as well as what effect each species has on each other. 6 pts Facilitation: The plants make the herbivorous animals come. Tolerance: The ginger and balsa play no roll in the arrival of bananas and ginger Rain forest on the windward facing slopes experience tree falling storms more often than the leeward slopes where storms rarely cause trees to fall. Which section of the forest (windward or leeward) would you expect to have a higher species diversity and why? (6 pts) To have the optimal amount of species you need to have a mixture of k and r selected species. On the winard there are many distrubances resulting in r-species on the leeward side there are some disturbances so you will have a mixture of k and r species. What is the trophic status of: (3 pts) Fruit eating mammals Primary Consumer Banana trees Primary Producer Predators on fruit eating mammals Secondary Consumer What will be the fate of the fallen tree that formed the light gap? (2 pts) It will become part of the decomposing food web. Would you expect the trophic transfer efficiency of the grazing food web of this ecosystem to be higher or lower than that of the prairie dog grassland example and why? (4 pts) The prarie dog system has a higher trophic transfer efficiency due to more NPP being available to be grazed by herbivores, while in the grazing food web a lot of the resources are locked in trees. Bonus questions What circulation cells meet at 30 degrees latitude? Hadley & Farrell What are the four basic components of any ecosystem? sunlight, producers, consumer, decomposer ...
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