Cuesta College Bio 211 Final Study Guide Questions and Correct Answers

what are the problems with over population? Why are we worried? 1) Famine and Disease. 2) loss of personal freedom 3) environment destruction When has most of the growth taken place in the population? Which decade have we seen the most growth? In the most recent decade. Right Now. Essay #1 Define Gause's Competitive exclusion principle. Give examples to show the experimental evidence supporting the principle. Causes hypothesis states that two species cannot occupy the same niche. If they attempt to one will have to change or one will become extinct. There is evidence to support this idea. This is shown in the Paramecium experiments. Experiment A: Two species are placed in separate aquaria. Results in both populations grew and did well. Experiment B: Two species are placed in the same aquarium. Looked at the population and found results that one did fine and the other died. Time after time he found this to be the same result. Gause's competitive exclusion principle If two species have the same niche they cannot remain for long in the same habitat. One will lose out and be eliminated (or at least reduced to a very small population.) Essay #2 Niche Compare and contrast spatial and temporal niche partitioning. Give the definition of each. Give a specific example from the lab for each Spatial niche partitioning when two species attempt to reduce competition by using different resources or using resources in different areas. EXAMPLE: Birds with different size beaks feed on different size seeds. birds will not have competition because they are use different resources. TEMPORAL: When two species attempt to reduce competition by using resources at different times. EXAMPLE: hawks are diurnal and owls are nocturnal. Both eat rodents but at different times. Essay #3 Energy flow - Discribe energy flow through ecosystems. Tell what law relates to the loss of energy at each transfer. Diagram a specific example for the Hypothetical ecosystem showing both percent and calories for at least 4 trophic levels. Second law: when energy is transformed in a living system much of the useful energy becomes useless. EXAMPLE: grassland food chain - Grass (Producer) w/ 100,000 cal is eaten by mice (primary consumer) and taking in 10,000 cal while 90,000 cal are lost as heat. Mice are eaten by snakes (secondary consumer) that take in 1,000 cal while producing 9,000 cal of heat. - Snakes are eaten by hawks (top carnivores) that take in 100 cal while producing 900 cal of heat. - The Length of Food chains is limited by entropy Essay #4 Diversity - Define Ecological diversity and ecological stability. Describe the general relationship between these two concepts in an ecosystem. How do these concepts apply when comparing the Sea Otter food web to a food web of a fresh water marsh? If an ecosystem is very diverse it is usually stable. Simple ecosystems can be unstable Removing organisms from a simple system can disrupt it more easily than a complex system. The Hypothetical sea otter food web is very simple. Removal of one population could result in totally disruption of the ecosystem. If abalone are removed for example the sea otter population would crash. The salt march food web in contrast is diverse and much more stable. Removal of any one population could have little effect on the overall ecosystem since other populations can fill the gap. Hierarchy of Organization Biological organization is the hierarchy of complex biological structures and systems that define life using a reductionistic approach Agassiz Story Student and the fish look beyond what you see do not set limitations to what you can interpret when observing a specimen Snail Lab / Snail Movement Snails move counterclockwise; snails know which way is up compared to down