The intercepts of the equation x2 + 4y2 = 16 are ______________________________. (pp. 1819)
Paul Murdock Dr. Kinkle Biology II Exam 4 University of Cincinnati LO #1 Muscle extension occurs passively. The sliding-filament model illustrates muscle contraction by showing the thin and thick filaments sliding past each other but remaining the same length. Muscle contraction is powered by myosin molecules. Contraction requires ATP, creatine phosphate, and glycogen. Tropomyosin covers myosin-binding sites on actin while the muscle is at rest. Tetanus: high rate of muscle contraction and little space between stimuli. Fast twitch muscles work by pumping calcium ions faster and there’s more SR In slow twitch the calcium ions remain in the SR (sarcoplasmic reticulum) longer LO #2 Uniform dispersion occurs because of competition. Clumped dispersion is the most common. Windblown dandelions exhibit random dispersion (wind-blown) Logistic growth: rate of increase approaches zero as the population size approaches the carrying capacity LO #3 K-selection: refers to density-dependent selection of traits favored at high densities R-selection: refers to density-independent traits that are favored at low densities Metapopulation: maintained by gene flow (source to sink). Movement of individuals between linked local populations. LO #4 Commensalism (+/o), inter-competition such as predation or competition (-/-), symbiosis (+/-), facilitation and mutalism (+/+). Ecological niche: sum of species’ use of biotic (living) and abiotic resources in its environment. Shannon diversity is used to calculate species diversity. Includes evenness and richness, such as the number of species and how they are distributed. More diverse= more stable, higher biomass, and more resistant to invasive species. Trophic: feeding relationships. Food webs link food chains. Food chain length limited by 10% of energy flow between predator/prey. Keystone species: exert strong central control on community structure by their niches, but are not the dominant species. LO #5 Intermediate disturbance: results in greatest species diversity Disturbances keep communities from reaching equilibrium (nonequilibrium model) Ecological succession: disturbed species replaced by different species. Primary: replacement of lifeless colony; secondary: existing community cleared by disturbance (soil still intact). Species richness is greatest near the equator LO #6 Population: same species, community: different species same environment, ecosystem: nonliving and living working together Energy flow: energy flows through ecosystems Nutrient cycling: recycles resources in ecosystem (recycle by decomposers) Photosynthetic production sets the spending limit for the ecosystem’s energy budget. GPP: energy from light converted to chemical energy NPP: GPP minus energy used by primary producers for respiration NEP: GPP minus total respiration of all organisms. Measurement of total biomass accumulation. Eutrophication: enrichment of ecosystem with chemical nutrients, sometimes excess may damage water supply or can be due to excess water-runoff killing most of the plants allowing the nutrients to accumulate. Batesian mimicry: non-toxic resembles toxic species. LO #7 Energy flow only 5-10% between trophic levels due to loss of heat as energy. Phosphorus does not exist in gaseous form. CO2 cycles through atmosphere. Excess causes increased global temperatures since it is a greenhouse gas Nitrogen and Phosphorus are often limiting nutrients Nitrogen mostly in atmosphere whereas Phosphorus and Carbon have reservoirs in sedimentary rock Hubbard Brook experiment showed various environmental problems such as acid rain (nitrogen) and promoted protection of watersheds. Also showed how excess water runoff made drinking water unsafe by allowing nitrate to accumulate. LO #8 Ecosystem diversity: extinction of one species may negatively affect other species in ecosystem. Aspirin and medicine derived from natural resources, important to keep biodiversity. Ecosystems purify our water, detoxify air, etc. Major threat to biodiversity is habitat loss, but also includes introduced species, overharvesting, and global change Cloning can be used to resurrect species Small populations are vulnerable to less biodiversity because of inbreeding, as well as genetic drift Declining approach looks at environmental factors to understand why a species declined LO #9 Landscape conservation efforts include: Movement corridor: narrow strip of small habitat clumps connecting isolated patches Biodiversity hot spot: contains endemic, endangered, and rare species and local laws prevent humans from interfering (zoned reserve). Biological magnification: toxins increasing in body at each trophic level (opposite of energy flow). Toxins not degraded by microorganisms. Greenhouse effect: keeps T high by using gases in atmosphere to absorb infrared emitted by Earth and re-reflect it, causing temperatures to rise. Deforestation contributes to greenhouse emissions. Ozone depletion: ozone layer protects species from UV radiation. Excess UV causes cancer, phytoplankton to die, negatively affects crops, etc.