BIOL 473 Exam 2 Questions And Answers Graded A+

pH forumla - CORRECT ANSWER-pH=-log[H+] Buffering Capacity - CORRECT ANSWER-the ability of a substance to resist changes in pH when acids like CO2 are added Sources of CO2 - CORRECT ANSWER-Atmosphere, respiration, solution of mineral carbonates CO2 is lost from solution by - CORRECT ANSWER-Diffusion into the atmosphere, uptake during photosynthesis Photic Zone - CORRECT ANSWER-Where there is enough light to fuel photosynthesis Acid Neutralizing Capacity (ANC) - CORRECT ANSWER-aka alkalinity or buffering capacity, ability of a solution to resist changes in pH upon addition of acids or bases, due to the presence of weak acid ions (like bicarbonate, carbonate, and hydroxide) that can absorb H+ ions, ANC is equal to the sum of base cation minus the sum of strong acid anions Carbonic acid dissociates into - CORRECT ANSWER-Bicarbonate and H+ Bicarbonate dissociates into - CORRECT ANSWER-Carbonate and H+ When the concentration of bicarbonate and carbonate increases, ___ - CORRECT ANSWER-the pH increases, solution gets more basic Most lakes are at what pH range - CORRECT ANSWER-6-9 Watersheds with limestone result in: - CORRECT ANSWER-becomes super basic, calcium carbonate becoming a buffering solution, carbonic acid helps dissolve rock to produce calcium bicarbonate which increases the amount of Ca2+ and HCO3- in the water, pH is increased due to the dissociation to form OH- Marl Lakes appear white because: - CORRECT ANSWER-High pH, lots of calcium carbonate, well buffered, super hot days increase photosynthesis so CO2 decreases, calcium carbonate (CaCO3) precipitates out of the solution and the lake appears white Vertical distribution of CO2 is driven by - CORRECT ANSWER-the balance between photosynthesis and respiration High CO2 concentration makes lakes (more/less) acidic - CORRECT ANSWER-more acidic, decreases pH Redox Potential - CORRECT ANSWER-When the oxygen concentration is above 0, the solution has a relatively high redox potential and is an oxidizing solution, if the solution is anoxic, the solution is a reducing solution and has a very low redox potential Redox potential is affected by: - CORRECT ANSWER-pH, oxygen level (main), and temperature Iron (Fe) is: - CORRECT ANSWER-Micro-nutrient essential to most organisms, required for chlorophyll production and essential for cellular function (Hb) In water with high redox potential, iron goes from __ to __ - CORRECT ANSWER-Fe2+ is oxidized to Fe3+ Iron is soluble when its in ___ form, this occurs in __ habitats - CORRECT ANSWER-Fe2+, occurs in anoxic habitats Sulfur is usually found as __ in freshwater, and is the __ most common anion following carbonate (CO3 2-) - CORRECT ANSWER-SO4 2- , 2nd Sources of sulfur - CORRECT ANSWER-Human: fossil fuels, natural: volcanoes Humans add ___x more sulfur than natural source - CORRECT ANSWER-2.4 Under extreme reducing conditions, highly insoluble ___ can form and be deposited into sediments - CORRECT ANSWER-FeS Reduced forms of Sulfide - CORRECT ANSWER-H2S, FeS Oxidized forms of Sulfate - CORRECT ANSWER-SO4 2- Silica (Si) is an essential nutrient for: - CORRECT ANSWER-diatoms, need Si to build the frustules that encase them, also used by other phytoplankton, freshwater sponges build glassy spicules from silica they extract from the water Sources of Silica - CORRECT ANSWER-Feldspar rocks Losses of Silica - CORRECT ANSWER-Diatom blooms Characteristics of Cyanobacteria (Blue-Green Algae) - CORRECT ANSWER-Prokaryotes, single cells, filaments or colonies, some have heterocyst cells believed to be the major site of N-fixation, can produce toxins, structurally and physiologically like bacteria, but function as plants Bacillariophyceae (diatoms) - CORRECT ANSWER-Silicified cell walls, divided into the centrate (radial symmetry) and pennate forms, associated with the "spring bloom" Buoyancy can be controlled by: - CORRECT ANSWER-synthesizing fats and oils that can alter density (ex. blue-green algae) Growth Characteristics of Phytoplankton - CORRECT ANSWER-Light and temperature (impact photosynthetic and cell division rates, photosynthetic rates are high when light intensity is high, photosynthetic rates are high when the temp is ~20-40 degrees C), limiting organic nutrients (N, P, Si) Cell Quota - CORRECT ANSWER-cellular content of a nutrient in a phytoplankton cell, a minimum cell quote is required for growth and reproduction, changes based on the species Luxury Uptake - CORRECT ANSWER-Ability of some species to uptake more nutrients than they need for growth and reproduction, excess can be stored and used in the future 3 Soluble Vitamins - CORRECT ANSWER-B12, Thiamine, Biotin Auxotrophic - CORRECT ANSWER-Algae that require extracellular vitamins Heterotrophy - CORRECT ANSWER-Organism that cannot produce its own food Photoautotrophs - CORRECT ANSWER-Derive energy for metabolism through photosynthesis, require light to grow Mixotrophic - CORRECT ANSWER-Capable of supplementing photosynthetic energy with energy derived from organic compounds, not light dependent, can often grow in the dark Paradox of the Plankton - CORRECT ANSWER-The competitive exclusion principle states that the number of competing species that coexist is limited to the number of limiting factors in the system, in lakes there are a small number of variables (light, temp, N, P, Si, etc.), but still usually 30-80 species coexist at a time, this is because lakes are NOT homogeneous, so conditions and limiting variables can be different based on location Types of microzooplankton - CORRECT ANSWER-Rotifers, protists Characteristics of Rotifers - CORRECT ANSWER-most are benthic, density/abundance of 200-300/L, very small body size (0.1 mm), omnivorous feeders (consume a mixture of algae, bacteria, and detritus), mostly grazers, some are predators (prey on other rotifers and small protozoans) Rotifer Reproduction - CORRECT ANSWER-Most reproduction through parthenogenesis (asexual reproduction, growth occurs without 2 gametes combining, unfertilized), but in unfavorable conditions can switch to sexual reproduction (fertilized eggs) and produce resting eggs Types of mesozooplankton - CORRECT ANSWER-Cladocerans, Copepods Types of macrozooplankton - CORRECT ANSWER-Larval insects, small decapods Characteristics of Cladocerans - CORRECT ANSWER-Ex. Daphnia, relatively large (0.5-3mm), important grazers, most are herbivores and feeding can be size selective (food ranges from small bacteria to larger BG algae), have a high feeding rate, some are predators of other zooplankton, food source for fish, life cycle is completed in a few days (development of offspring) and are generally multivoltine (species that have 2 or more broods of offspring/year), feeding selectivity is based off of the largest algal cell they can ingest Cladoceran Reproduction - CORRECT ANSWER-Reproduction via parthenogenesis, can also switch to sexual reproduction in unfavorable conditions, but results in diploid resting eggs that are equivalent to seeds in plants, males are rarely produced Characteristics of Copepods - CORRECT ANSWER-Grazers, omnivores, predators, seize particles prior to filtering the using secondary maxillae, filtering/raptorial (grabbing), most evasive, have sexual dimorphism Copepod Reproduction - CORRECT ANSWER-Sexual reproduction, can produce resting eggs that become part of a 'seed bank' in lake sediments, viable for >300 years due to diapause, reproduce once/year, slower reproductive rate due to long developmental time for eggs and time to reach sexual maturity Feeding Considerations of Zooplankton - CORRECT ANSWER-Most are filter feeders eating algae, bacteria, and detritus, filtering rates are a function of temp and body size (larger body size = higher filtering rate and can eat larger particles), cladocerans are the most generalist grazers of algae and selectivity is based off of the largest algal cell they can inject Reynolds Number - CORRECT ANSWER-Ratio of inertial forces to viscous forces that act on an object moving through fluid, lower Reynolds number = greater importance of viscous forces, if RE <1 viscosity is important, low RN often describe the movements of filtering appendages of zooplankton, protists have the smallest (0.01) Types of Predator Avoidance - CORRECT ANSWER-Behavioral, Morphological, Life History Behavior Adaptation of Predator Avoidance - CORRECT ANSWER-Diel Vertical Migrations, adaptation for avoiding visual-feeding predators like fish, zooplankton at the bottom of the lake during the day, towards the top of the lake at night Morphological Adaptations for Predator Avoidance - CORRECT ANSWER-Cyclomorphosis: alter body shape to make it more difficult for predators to ingest them, body shapes are either fixed or flexible, many morphological defenses are inducible: zooplankton can smell their predators using chemical communication (kairomones) Life History Adaptations for Predator Avoidance - CORRECT ANSWER-Some can alter their reproductive patterns and rates as predation intensity varies, increased allocation of energy to reproduction, decreased size at maturity, and decreased age at maturity can all change to offset population losses Ecological Importance of Zooplankton - CORRECT ANSWER-Most important grazers of algae and important food source for fish, key for nutrient cycling through sloppy feeding, determine the N:P ration and therefore what species of phytoplankton will dominate Fish Reproduction - CORRECT ANSWER-mostly through sexual reproduction (some parthenogenesis) Differences in spawning behavior are due to: - CORRECT ANSWER-Degree of parental care, courtship behavior, timing of spawning (age, seasonal), location of spawning Andromous - CORRECT ANSWER-Spawn in freshwaters and spend most of their life in marine environment (ex. salmon) Catadromous - CORRECT ANSWER-Spawn in marine systems and spend most of their life in freshwater habitats (ex. freshwater eel) Tropic Ecology costs and benefits - CORRECT ANSWER-Benefit: amount of energy consumed per prey item, Cost: energy and time required in search, attack, and handling of prey, interaction with prey and optimal foraging (costs are a function of mouth morphology of predator, and its behavior) Trophic Ontogeny - CORRECT ANSWER-Fish will change prey as they develop and change size, costs of feeding on certain prey changes with growth Gape-limited - CORRECT ANSWER-Young fish that consume their prey whole are limited to prey smaller than their mouth gape Functional Response - CORRECT ANSWER-Relationship between prey density and the feeding rate of predators, at low prey density predator feeding rate is limited by its encounter rate with prey, graph is feeding rate (prey/hr) vs. density (#/m3) Paiklotherm - CORRECT ANSWER-Means that fish are cold blooded, so temp modulates their metabolism and feeding rates Types of Feeding Modes in Fish - CORRECT ANSWER-Planktivores, Piscivores, Benthivores Planktivores - CORRECT ANSWER-Prey on mostly plankton (especially zooplankton) Piscivores - CORRECT ANSWER-Prey mostly on other fish Benthivores - CORRECT ANSWER-Feed mostly on benthic prey, most fish eat some benthic prey Environmental Factors that Impact Distribution of Fish - CORRECT ANSWER-Temperature, oxygen concentration, light regimes, habitat heterogeneity, temperature impacts metabolism of fish in a non-linear fashion (fish have thermal constraints) Morphoedaphic Index (MEI) - CORRECT ANSWER-Predicts the total fish population of a lake based on its mean depth and the concentration of dissolved solids (MEI=TDS/Z) Seasonal Plankton Succession in temperature, dimictic lakes - CORRECT ANSWER-- Winter: cold and dark, little PS, accumulation of nutrients because of low demand by primary producers - Late Winter: Some light penetrates ice and supports weak phytoplankton bloom - Spring: before stratification (water column still mixing), lots of nutrients that phytoplankton can't use because they're being mixed too deep in the water column, once lake has stratified there is a spring bloom (increased nutrient and light availability), often results in depletion of most soluble nutrients in eutrophic zone (Si, P), typically spring bloom is Diatoms - Late Spring: Daphnia phase (they eat diatoms), very efficient grazers and produce a 'clear water phase' (clear water phase: increased density of cladocerans, only temporary because they die off after overgrazing their food - Mid/lake summer: a) in eutrophic lakes: phytoplankton recover to high levels, community is dominated by BG algae b) in oligotrophic lates: phytoplankton remain at low density following clear water phase Selective Grazing, zooplankton and phytoplankton - CORRECT ANSWER-Zooplankton show selectivity in grazing which alters the phytoplankton community, also controls the N:P ratio by controlling which phytoplankton species dominates, competition between phytoplankton species is strongly affected by grazers, some phytoplankton have effective strategies for 'being big' and reducing their grazability Size-Selective Predation by Fish and Invertebrate Predators - CORRECT ANSWER-Invertebrate predators are selective for small-bodied zooplankton, planktivorous fish generally feed on the largest zooplankton available (visual-feeding), in lakes with lots of fish, small zooplankton will dominate and vice versa What caused cholera outbreak in lake WA and how was that issue solved at the time? - CORRECT ANSWER-Putting raw sewage into the lake, chlorination of lake WA What river was diverted into lake WA and why? - CORRECT ANSWER-Cedar River, to fix the lake level issue and fill it, drains snowmelt from cascades and brought sediments Why did the first attempt to introduce Sockeye Salmon fail? - CORRECT ANSWER-There was too much energy and sediments in the Cedar River for salmon to spawn, lots of silt and mud