LIFE 320 Final Exam - Questions and Answers

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LIFE 320 Final Exam - Questions and Answers Relationships between populations in an ecosystem are often represented using models that show whether a population has a positive or negative effect on t... he size of another population, and whether this effect is direct or indirect. Common symbols used for these types of interactions are shown below. This type of relationship modeling can be done for kelp forests, which are marine ecosystems found primarily along rocky shorelines of the North Pacific Ocean. In kelp forests, kelp provides a food source for sea urchins, which in turn provide a food source for sea otters. Based on the information given above, which of the following models best represents the relationships between kelp, sea urchins, and otters in a kelp forest ecosystem? Negative, negative, positive (outside) Poison ivy is a weed that produces an oil that causes skin rashes. Scientists want to perform an experiment to see if poison ivy grows taller when exposed to more carbon dioxide. How should the control group in this experiment be treated? The control group should have plants growing at normal carbon dioxide level. Which of the following is true about evolution by natural selection? Mutations occur randomly and may increase in frequency or be eliminated as a result of selection pressures in the environment. Most scientific investigations begin with a set of facts about nature. These facts are obtained by observation and description. Because it is difficult to experiment on large ecological systems, researchers often replicate the essential features of a system in smaller, simplified laboratory or field settings known as Microcosms Which interaction is characterized by negative effects on the fitness of both species involved? Competition The formulation of hypotheses is a critical step in the scientific process. In the simplest terms, what is a hypothesis? an explanation Organisms that use photosynthesis or chemosynthesis are autotrophs. Fishermen living along the North Pacific Rim felt threatened by increased populations of sea otters because sea otters consume commercially valuable abalone, sea urchins, and spiny lobster. What beneficial aspect of sea otter ecology did these fishermen ignore? Sea otters catch and eat sea urchins, thereby protecting kelps, which in turn shelter populations of larval fish. A mixotroph is an organism that can use multiple methods to obtain energy. Some have proposed that humans might, individually, attempt to combat climate change by replacing their roof shingles with light or white-colored shingles rather than dark or black-colored shingles when replacing the roof of their homes. The notion behind this idea is increasing the albedo of Earth's surface. The energy of incident solar radiation reaching the surface of Earth declines toward the poles from its maximum in equatorial regions. Which of these is NOT a reason for this? The tilt of earth increases the reflection of solar radiation Which of the following phenomena triggers an El Niño-Southern Oscillation event? reversal of high- and low-pressure areas in the equatorial central Pacific Ocean Dry climates may be the result of Hadley cell circulation and the rain shadow effect. Coral reefs are most similar to tropical rainforests. Why is water at the bottom of a temperate lake likely to be close to 4°C year-round? Water is densest at 4°C. In which lake zone would photosynthesis not occur? profundal zones Biomes are geographic regions Whose plant communities have similar adaptations Which of the following pairs is an example of convergent evolution? birds and bats The greenhouse effect is so named because Earth's atmosphere acts like the glass of a greenhouse. Thermohaline circulation is driven by: temperature and salinity [Show More]

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