Warm-Up: LAB #12 • DIRECTIONS: Answer the questions in your NB. • What was the purpose of doing this lab? • What was the independent and dependent variables for 12-A & 12-B? • What 3 things did you learn? • What will you do next time to prepare for a lab better?
TIPS FOR STUDYING • Examine the UNIT syllabus, answer the questions, study the vocabulary terms. • Read the chapters at HOME. This is the ONLY way to reiterate what was taught in class. • Study EVERY night, SO CRAMMING before an exam doesn’t become a bad HABIT! • When I give you the 4 free response questions(I will only choose 2), look online at the college board for how they will be graded.
LAB QUESTIONS • Rate of O2 production, Rate of CO2 uptake, Rate of carbohydrate or biomass. • For each millimeter of oxygen produced, 0.536 milligrams of carbon is assimilated(absorb, take-up). • The relationship is an inverse one. As the temperature in a liquid rises, the amount of gas that remains dissolved in a liquid decreases. The most oxygen-rich water is shallow, rapidly moving, and cold. At 4*C, water can hold approximately 19% oxygen.
LAB QUESTIONS CONTINUED • Water is much thicker than air. This means that the gill muscles work much harder to move water over the gills’ surfaces. Another factor is that water holds much less oxygen (5 to 10 mL/L) than does air (200mL/L). • You should expect a higher DO reading in the stream water in comparison to the lake water. As the stream moves over rocks in the stream bed, the tumbling action oxygenates the water. Also, the shallowness of the stream means that more water comes in contact with the atmosphere, thus increasing the amount of oxygen carried in the water. • The DO at 7am would be LOWER than the DO at 5pm. The DO would have been reduced greatly by respiration by all organisms (NOT just phototrophic organisms) throughout the night and morning, while the low levels of light early in the morning would not produce as much DO through photosynthesis as would be produced by light o f increasing brightness later in the day.
LAB QUESITONS CONTINUED • At a particular temperature, only a fixed amount of oxygen could be dissolved in a given volume of water. Since the volume of water is greater, the amount of oxygen dissolved in the water would be greater. (The slightly larger surface area in B at the air/water interface would allows for a slightly greater rate of diffusion from the atmosphere into the water, but the difference would be so insignificant compared to the difference attributable to the volume of water.) Over the course of a day, the fish would use up the DO in both containers, and the one with more surface area (B) would better sustain the fish. The term “oxygen available” depends on time. Initially container A would have more; over time, B would have “more available” due to surface area.
LAB QUESITONS CONTINUED • Eutrophication is the increase in concentration of N, P & other nutrients in bodies of water. N & P tend to be limiting nutrients in natural bodies of water. (N tends to be limiting in marine & estuarine ecosystems & P tends to be limiting in freshwater ecosystems). By increasing the amounts of these nutrients in bodies of water, the types of organisms that are most successful or that have the greatest biomass change. These changes affect the entire ecosystem. The most common effect is for there to be tremendous blooms of algae. These algae produce large amounts of oxygen during the day, but respiration by the algae at night often depletes the DO to zero at night. In addition, dense growth of algae at the surface may shade out the waters beneath, limiting the primary productivity and causing anoxia in the underlying waters. The algae often eliminate (through competition) the natural food of herbivores in the ecosystem.
POPULATION REVIEW QUESTIONS • What models are useful in describing the growth of a population? • How is population size regulated by abiotic and biotic factors? • What are the various animal behaviors? • Define population density. Give two methods biologists use to estimate population densities and distinguish between uniform, clumped, and random distributions, and indicate the conditions under which one is the most common. • Draw an exponential growth curve(J-shaped curve). • Draw a logistic growth curve(S-shaped curve), and label the carrying capacity, the inflection point, the portion of the curve showing an accelerating rate of population growth, and the portion showing a decelerating rate. • Explain how density-dependent and density-independent factors operate in limiting population growth. • Using examples, discuss the ways in which parasitism, predation, intraspecific competition, emigration, mutualism, and physiological and behavioral mechanisms can act as density-dependent limitations on population growth. Explain, using an example, how destroying the balance between predator and prey in a community can upset the ecology of an area. • Carefully define the concept of ecological niche, and explain its significance with respect to the competitive exclusion principle. Specify the three possible results of intense interspecific competition. • Explain the types of interspecies relationships and tell how each member of the pair is • affected by the interaction(include predation, parasitism, commensalism and mutualism).
What models are useful in describing the growth of a population? • EXPONENTIAL • R • Very rapid • Assumes resources are unlimited • LOGISTIC • K • Population will increase until it reaches its carrying capacity • Knows there is a limit of resources
How is population size regulated by abiotic and biotic factors? • Availability or resources • Living environments • What else???? YOU TELL ME!!!
What are the various animal behaviors? BEHAVIORS • innate • instinct • pheromones • drives • habituation • learned behavior • classical conditioning • operant conditioning • insight • parental imprinting • Kinesis • taxis • social behavior • dominance hierarchy (pecking order) • altruistic behavior • fixed action pattern • sign stimulus • critical period • monogamous • polygamous • polygynous • polyandrous OTHER WORDS TO CONSIDER MAKING CONNECTIONS TO
Define population density. Give two methods biologists use to estimate population densities and distinguish between uniform, clumped, and random distributions, and indicate the conditions under which one is the most common. POPULATION DISPERSION TYPES • CLUMPED • Individuals aggregated in patches • UNIFORM • Individuals are evenly spaced • RANDOM • Position of each individual is independent from others • COUNT ALL OF THEM • Census, is an example • AVERAGE DENSITY • Estimated based on the population density. • MARK CAPTURE METHOD • Formula • [(# tagged 1st time) x (total # captured)] / (total # recaptured that were tagged) WAYS TO COUNT A POPULATION DEFINITION (Population density): # of individuals per unit (volume/area).
Draw an exponential growth curve(J-shaped curve).Draw a logistic growth curve(S-shaped curve), and label the carrying capacity, the inflection point, the portion of the curve showing an accelerating rate of population growth, and the portion showing a decelerating rate. S-curve (LOGISTIC) (k) J-curve (EXPONENTIAL) (r)
Explain how density-dependent and density-independent factors operate in limiting population growth. DENSITY-INDEPENDENT LIMITING FACTORS • Temperature • Natural Disaster • Sunlight • Human Activities • Physical characteristics • Behaviors • Competition • Predation • Disease • Parasitism • Crowding • Stress DENSITY-DEPENDENT LIMITING FACTORS
Carefully define the concept of ecological niche, and explain its significance with respect to the competitive exclusion principle. Specify the three possible results of intense interspecific competition. ECOLOGICAL NICHE • DEFINITION: the status of an organism in it’s community. • SIGNIFICANCE • If every organism was doing the same part, would the community be effective in its operation? 3 RESULTS OF INTENSE INTERSPECIFIC COMPETITION