LS7B Final Study Guide
describe logistic growth
1) at 1st, growth reflect rate @ which ind can reproduce. Growth rate inc rapidly & look exactly like exponential growth rate 2) middle of graph, factors of resource that affect pop. Growth rate is max when N=1/2k. After pass 1/2k, growth rate start to dec to linear growth rate; growth rate above 1/2k is smaller than growth rate below is 3) as pop size N approaches k, growth rate slows bc of crowding & competition 4 resources
population
A group of individuals that belong to the same species and live in the same area
Predation
1 org (predator) consume other (prey) Predator-prey sys oscillate density Stable if sufficient areas where prey can escape predation temporarily Predation can limit pop size of prey 2 extent comp exclusion no occur
ammensalism
1 species in interacting pair harmed w/ no apparent effect on other
decomposer
break down dead tissue-fungi, bacteria, C return to air
how add CO2 to air?
burn fossil fuel, cut down forest
how do large animals get O2 in water
by move around bc water O2 poor so it go in their gills
how do scientists estimate pop size
Mark & recapture 4 moving org Pop size N= (tot caught on 2nd day/recaptures) x marked on 1st day N=(C/R) x M Sedentary (nonmoving) org: estimate by density; throw hoop, org # in that
A conservation group has established a new sanctuary for an endangered species of rabbit. What are the ideal characteristics of this sanctuary? A) The sanctuary is seeded with enough rabbits that they can easily find mates. B)The sanctuary is not populated by rabbit predators C).All of these choices are correct D).The sanctuary is located in close proximity to another local rabbit population of the same endangered species. E) The sanctuary is large enough to support a growing number of rabbits.
c
An environment can only support a certain number of individuals of a given species at any one time. This number is referred to as the _____ of that environment.
carrying capacity
What are the units of per capita growth rate (r)?
change in individuals per unit time/individuals at starting time
resource partitioning can lead to
character displacement niche specializtion
Measurable increases in carbon dioxide in the atmosphere over the past 200 years have resulted primarily from human addition of carbon dioxide from:
clear cutting forests.burning fossil fuels for heating, cooling and transportation.
In addition to burning fossil fuels, humans return CO2 to the atmosphere faster than it can be removed by:
clearing forests 4 agriculture
How would climates be different if Earth's axis of rotation were perpendicular to incoming solar radiation rather than tilted at 23.5 degrees?
climates no show strong seasonality
The CO2 level is _____ during winter in the northern hemisphere compared to levels in the summer.
higher
From what you know about how species diversity changes with latitude, predict how species diversity changes with altitude.
higher altitude= fewer # of species
A population that is decreasing in size will have an age-structure histogram shaped like a(n):
inverted pyramid, with a narrow base representing a small number of young individuals. Populations that are decreasing in size have a smaller number of reproductive individuals compared to individuals beyond reproductive age
Aquatic trophic pyramid
inverted; E lots @ bottom, biomass lots @ top
What are three examples of species that have benefited and three examples of species that have been harmed by human activity
invasive species benefit, coral frogs, etc not benefit
continous growth
life cycle not synchronized, so ind reach sexual maturity @ diff times & can reproduce immediately, so pop can inc/dec continuously
Law of tolerance
limits of environment so pops of all species no worldwide distribution
carbon cycle
linked network of biological & physical processes that shuttle C among rocks, soil, oceans, air, & organisms
parasitism
live close association w/ other species, gain nutrition by consuming host tissues Rarely kill, reduce hosts' fitness & ability 2 reproduce & tap its resources Can limit pop size of host
A town has several lakes connected by small streams or creeks. All the trout within a single lake are considered a(n) _____. The trout in all of the lakes constitutes a(n) ______.
local population, metapopulatino
Most populations demonstrate _____ growth, in which the population size increases exponentially until it levels off near the carrying capacity (K value) of the habitat for that species.
logistic
How can plant diversity influence rates of primary production in terrestrial ecosystems?
multiple species exist together let them inc primary production
functionally redundant
multiple species that are present in the same ecosystem and perform the same function
What is the difference between a population and a species?
population is all ind of a given species that live and reproduce in particular place at particular time. species include all populations
How do r and K strategies relate to the predictability of the environment? In which kinds of environment is each strategist more successful
r strategists many offspirng- unstable environment. k strategists few offspring- stable environment
Plot a survivorship curve for a species with high rates of predation early in life and one for a species with high mortality late in life. Name the type of survivorship curve displayed in each graph.
tYpe III, type I
Global patterns biodiversity largely determine by
temp and precipitatoin
phylogenetic niche conservatism
tendency of species 2 retain aspects of their ancestral niches, & therefore closely related species 2 resemble each other in niches
A biological reserve that is designed for a single species is an important tool in maintaining biodiversity because a reserve:
that is designed for a single species will also protect other species in the reserve.
An individual's ecological footprint is equivalent to:
the amount of land required to provide all the resources used by that individual.
Population range is:
the area over which a population is spread.
Character displacement
when species coexist have more distinct differences than if they don't coexist (if don't coexist, more overlap)
How do reserves and corridors help to conserve biodiversity
reserves protect loss, and corridors maintain diversity
competiitve exclusion can lead to
resource partiioning; Comp exclusion can → divergence in strategy→ speciation→ resource partition→ accumulate diff morphology
Overlap of niches can be minimized through:
resource partitioning. Partitioning resources available in an area means that more than one species can exist there. Resource partitioning allows subdivision of a resource into smaller parts so that instead of one species being outcompeted for a resource and eliminated from a region, they can coexist.
In control experiment, keep___ same of mosss
resources
Measuring the costs and benefits of a mutualism in terms of energy spent and/or gained:
results in gain for both individuals.
Decomposers are vital components of a food web because they:
return carbon (as CO2) to the atmosphere.
Upwelling near continent shore
return nutrient to surface
biggest reservoir
sedimentary rocks (like coal, petroleum, natural gas)
Communities
set all pops of 2+ diff species found in a given place @ particular time
Coral reef
shallow tropical, nutrient low, algae high→ primary producer high, invertebrates, fish
Trophic pyramid:
show biomass supported @ each lvl by the biomass & E lvl beneath it
How does a food web that diagrams the movement of carbon through an ecosystem also show how energy is transferred from one organism to the next?
solar energy from plants to glucose; both C cycle and E transfer
what is climate determined by
solar radiation, global patterns of wind & ocean circulation, & Earth's varying topography
Explain how incoming solar radiation exerts a direct influence on the distribution of temperature across Earth's surface.
solar strikes curved earth at an angle. same solar energy distribute @ diff angles
Evaluate data on the effects of alterations to biogeochemical cycles
uh idrk
Predict general patterns of species diversity on islands.
uh yes further away= less diverse
Large, even distances typically separate individual panda bears from each other. What type of population distribution do pandas exhibit?
uniform distribution
The figures shown represent three hypothetical populations; each circle is an individual. Which figure depicts a pattern that illustrates a scenario in which individuals establish exclusive territories to secure access to resources?
uniform distribution
endangered species
unlikely 2 persist w/o hunan intervention
how 2 see environment disruption
use amphibians bc they get water through skin
Lake
vary, aquatic plant & green algae, cyanobacteria, zooplankton fish, turtle bird
Terrestrial biomes:
vascular plants dominate, carnivorous vertebrates
Oceanic zone:
vast open ocean from the edge of the continental shelf outward
How do geologic processes participate in the long-term carbon cycle
volcanism (add CO2) , chem weathering (remove CO2) , plate tectonics ( create mtn, afffect rate C is buried in sediments and inc chem weathering) , oxidation coal, oil, other forms of ancient organic matter (add CO2)
facilitation
when 1 species creates environment that helps another (indirect) Can include both mutualism & commensalism
mutualistic interaction
when benefit 4 each participant outweigh their costs Typical benefit: access 2 nutrients, shelter from predator/weather, direct help w/ reproduction (benefit measure by natural selection, terms of reproductive output) Costs: proteins, fats, & carbs invested in build structure/tissue, E consume activity Each side act in own self interest; mutualisms r subject 2 natural selection Abundance each species inc by presence of mutualist
Biotic factor affect niche use:
when interaction w/ other species affect niche use (alive)
In what ways do habitat loss, overexploitation, and invasive species threaten biodiversity
# species habitat supports reflect its size
Theory of island biogeography:
# species occupy island depend on 1) size of island (larger island/more colonists=more species) 2) distance from island from source of colonists (more distant=lower colonization rate)
population growth equation
(births + immigration) - (deaths + emigration)=∆N/∆t=dN/dt=rN
facultative
(not rlly symbioses): association where 1/both participants can survive w/o other Many obligate mutualisms thought to begin as facultative
Disturbance
(severe physical impact on habitat, effect pop ind of densities)
denitrifying bacteria
bacteria which often live in damp soil, and which convert nitrates into nitrogen gas
Would you rather have a million dollars today, or start with one cent and double the amount each day for a month? Why?
1 cent per day exceded 10 $ mill
Compare and contrast a modern marine food web with food webs that existed two billion years ago.
2 bya made up bacteria & archaeon.
CO2 added 2 atmosphere through
1) geologic inputs (volcano & mid-ocean ridges) Volcano & midocean ridge form new seafloor release CO2 each yr Plate tectonics form mtn & ocean base/new crust=subduction return sediments 2 mantle where C stored, then recycle to surface as CO2 w/ volcano & ocean ridge Coal, oil etc in sed rocks=release fossil fuel Bacteria and fungi do fossil fuel release naturally 2) biological inputs (respiration) 3) human activity (deforestation, burning fossil fuels)
Co2 removed from atmosphere by
1) geologic-chemical weathering (CO2 rainwater react w/ exposed rock) 2) biological: photosynthesis
What are three factors that help determine the species composition of a community
1) inter/intra specific competition 2) freq of disturbance 3) movement of species in/out community
Major threats 2 biodiversity & ecological sys include:
1) overexploitation of resources ex) fisheries→ Collapse pop (agriculture & land use) 2) habitat loss (fragmentation & biodiversity) 3) climate ∆ 4) redistribution of biodiversity (invasive species, disease ecology)
describe diff types of pop distribution
1) random: ind appear random. No clear pattern where occur; equal chance any position Location of 1 ind no influence on where next ind will b found 2) cluster: resource cluster/spatial proximity 2 other ind enhance fitness Resource distribute patchily 3) uniform: resource limited or predators target a single species; ind may b better off far as possible from others Predator try 2 locate other species members nearby after find 1 ind
3 features of population
1) size=# ind of all ages alive @ particular time @ particular place 2) range=geographic range in which pop is spread. Reflect range of climate that pop tolerate & how many species pop encounters 3) density=depend on size & range. Tell how crowded or dispersed ind in pop
when did produce O2> consume O2
2 bill ya
how much percent E goes from 1 trophic level to next
10%
If the population size (N) is 1,000 individuals and the range is 10 km, what is the population density?
100 individuals/km The population density is the population size divided by the range. Since the population size is 1,000 individuals and the range is 10 km, the population density = 1,000 individuals / 10 km = 100 individuals/km
biology hotspots
2 dozen biology hotspots on land- relatively small areas w/ unusually high #s endemic species & under threat of human activities @ least 1500 endemic plant species & lost at leasty 70% original habitat Less than 2% earth's land surface, but more than ½ plants and 43% animals
Most climate models predict that during the 21st century mean global temperature will increase by:
2-5 °C.
where r deserts found
30 degree latitude
Order the stages of succession (1-4).1. Photosynthetic initial colonizers in a pond serve as prey for insects.2. As the number and type of species stabilizes, a climax community forms.3. The population growth of insects leads to the stabilization of a diverse population of species, including fish and amphibians.4. Agricultural runoff in a pond provides the nutrients necessary for the population growth of initial colonizers.
4 > 1 > 3 > 2 In the case of a pond, photosynthetic microorganisms (e.g., algae) are typical initial colonizers. The result of human activities such as agricultural runoff can provide the nutrients for the early growth of initial colonizers (#4). The growth of microorganisms can attract aquatic insects (#1), which in turn contribute to the growth of aquatic fish and amphibians (#3). As the species diversify, the number of species eventually stabilizes and does not undergo further change, becoming a climax community. This is the last stage of succession (#2).
A population of mice (primary consumer) consumes 5,000 kg of grass (primary producer). Approximately how much of the original biomass in the grass will be passed on to a tertiary consumer?
5 kg
Estimates are that all natural processes (not including human activities) result in a near balance between carbon entering and leaving the atmosphere (actually slightly less entering than leaving). What is the estimate of the excess CO2 in gigatons of carbon per year added to the atmosphere from human activities (that is, the amount above that removed by natural processes)? (Select the closest value.)
5.2 gigatons yr-1
What is the approximate percentage of total fixed nitrogen attributed to human activities?
50%
how much solar radiation no reach land
50%
when did inc nutrient lvl→ air like today (support humans)
580 mya
How many "cells" of circulating air are found around the Earth?
6
What is the approximate size of the human population today?
7 bill ppl
isolated species
: become extinct/loss genetic diversity quicker than connected ones (metapopulation)
describe temp control on earth
@ equator, solar E strike Earth directly, result in high influx of E per unit area=warmer than poles @ High latitude, incoming solar E strike Earth @ angle, result in lower fluxes of E per unit area=temp lower, also move variation
Which of the statements about coral bleaching is true? A) All of these choices are true. B) Corals appear white after bleaching because their white calcium carbonate skeletons are visible through their translucent tissue. C) Bleached corals die more rapidly than unbleached corals. D) Increased seawater temperature is one cause of coral bleaching. E) Coral bleaching results from the loss of algal symbionts from the coral tissue.
A
ecosystem
A biological community of interacting organisms and their physical environment.
Deciduous forest
A biome with four seasons, plants shed leaves in the fall and grow new ones in the spring.
Anthropocene Epoch:
A new epoch, not formally accepted by geologists, during which our species has become the dominant force for change in the biosphere. The Anthropocene marks the end of the Holocene epoch, about the time of the Industrial Revolution, 200 years ago.
Eutrophication
A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria
Chaparral
A scrubland biome of dense, spiny evergreen shrubs found at midlatitudes along coasts where cold ocean currents circulate offshore; characterized by mild, rainy winters and long, hot, dry summers.
climax community
A stable, mature community that undergoes little or no change in species over time
Island biogeography and relation to what
Arrival rate new species dec as species accumulate Extinction rate inc as ind from diff species compete 4 resources Eventually, arrival & extinction rates balance each other @ equilibrium pt ∆S (# species)= C(s) (colonization rate)-E(s)(extinction rate) Far islands lower colonization rates compare 2 near island Extinction rates aren't influenced by distance from source pops Larger island have more colonists & lower rates of extinction compared 2 smaller islands; species-area relationship
mtn air?
As air up mtn=cool=rain, in rain shadow=warm=arid=no rain
Describe anticipated effects of climate change on the distribution and evolution of biodiversity
As climates warm, species will migrate to regions that are consistent with their optimal living strategy, which usually means moving away from the equator and toward the polesFor some animals, they can't move any farther and may go extinct
Savanna
An area of grassland with scattered trees and bushes
Desert
An extremely dry area with little water and few plants
Neritic zone:
Area of ocean that extends from the low-tide line out to the edge of the continental shelf
Relate climate warming to changes in phenology, and how changing phenology of one species can affect the ecology of other species
As the climate warms phenology of species can change (reproductive cycle), which may affect other species who rely on certain blooming times or larvae spawning to eat
In general, what is the relationship between a country's ecological footprint and its overall standard of living?
As the standard of living increases, so does the ecological footprint.
Predict changes in biomass in trophic levels between top-down and bottom-up control.
Bottom-up control - increase or decrease in producers leads to increase or decrease in all trophic levels aboveTop-down control - increase or decrease in top predator → oscillating increase or decrease in levels belowEx. hawk pop increases, snake pop decreases, marine iguana pop increases, algae pop decreases
y aquatic plant need no structure
bc water denser than air (buoyancy), also nutrients dissolve in water
Taiga
Biome in which the winters are cold but summers are mild enough to allow the ground to thaw
Which of the answer choices is directly responsible for depleting the supply of oxygen in bottom waters?
bacterial growth
Long term C cycle
C in atmosphere inc over time. Geologic: role on timescale centuries & larger From physical geologic process- volcano, tectonic plates CO2 inc w/ glacial expansion, dec w/ glacial retreat Glacial period= C incorporate into ocean as sediments
Biomass generally declines substantially as we move upward from one trophic level to the next in a trophic pyramid. This pattern was discussed in this section in terms of energy loss from one level to the next, but carbon must be lost as well. What happens to it?
C lost return as CO2 to air. also decomposers and buried in sediments
Which of the results from a mark-recapture study done on mice would reflect a larger population size? A) When taking the second sample, 200 individuals are caught and 80 are marked from the first sample. B) When taking the second sample, 100 individuals are caught and 80 are marked from the first sample. C) When taking the second sample, 200 individuals are caught and 20 are marked from the first sample. D) .All of these scenarios would result in the same population estimate. E) When taking the second sample, 100 individuals are caught and 20 are marked from the first sample. Score: 1 of 1
C) When taking the second sample, 200 individuals are caught and 20 are marked from the first sample. When only 10% of the second sample is marked from the first capture period, it is indicative of a population that is very large. If the population were small, then there would have been a higher percentage of recaptures on the second day. The equation N = (C/R) × M can confirm this: N = 200/20 × 200; N = 2000
Autotrophs remove _____ from the air and fix this into tissues providing _____ for secondary consumers.
CO2, Energy
what types of greenhouse gases
CO2, water vapor, methane
deforestation can create
Can result in habitat loss & fragmentation (reduced quantity), habitat degradation (reduced quality) Creates "edge" habitats- support fewer species
• Draw a food chain and recognize how energy is transferred between each level
Carbon is transferred from one organism to another in a food chain.Goes from primary producer(largest) => primary consumer(Herbivore) (second largest) => predators, organisms that eat other consumers, are secondary consumers (third largest) => tertiary consumer (predator)(smallest) => Decomposers: feed on dead cells or bodies and return carbon dioxide and other inorganic compounds back to the environment, completes the cycle of the ecosystem From the base of plant productivity, about 10% of the biomass of each trophic level is passed on to the next-higher level. Only 10% of energy is transferred, 90% of energy is lost, so the biomass at one level is only 10% to 15% of the level below. This limits number of trophic levels in a food web.
• Relate species' interactions in and between communities to the carbon cycle
Carbon travels through the food web and interactions between species change the form of carbon (plants fix carbon in sugars that animals consume and then respire)
Draw and explain the curve representing the changing atmospheric levels of CO2 over the course of a year.
Co2 lower during summer bc photosynthesis lvls r higher
Consider this map, which illustrates annual carbon uptake due to primary production (g C/m2) by primary producers in the ocean. Primary production is dependent on nitrogen and phosphorus. According to the map, higher levels of primary production occur in coastal waters compared to the open ocean. What is the best explanation for this observation?
Coastal waters have higher levels of nutrient-rich runoff due to human agricultural activities than the open ocean. Runoff of nitrogen and phosphorus from the continents as a result of human activities are highest in coastal waters. Runoff provides nutrients for primary producers and results in higher levels of primary production in coastal waters.
Describe how community assembly is driven by colonization, competition, and extinction.
Communities form through interactions between species, whether it be competition or colonization. Extinctions make way for new species to arise in community
Define a community and recognize communities exist at a range of scales.
Community - The sum total of the populations that live in a given area
Discuss the importance of competition, predation, and symbiotic relationships (i.e., mutualism, commensalism, parasitism) in structuring natural communities
Competition, predation, and symbiotic relationships help structure natural communities b/c relationships between different organisms determine the energy and carbon flow in a community Competition can cause resource partitioning that can result in niche specialization: grow and bloom at different times, different niches within a tree for birds Predation: predator-prey oscillation
Differentiate between competitive exclusion and resource partitioning
Competitive exclusion - competition between two species excludes one species from occupying a certain niche, leading that species to change its niche Resource partitioning - species who have very similar niches evolve to use different resources, eliminating competitionCompetitive exclusion can lead to resource partitioning
how r humans part of ecosystem
Competitors & predators ex) fisheries Mutualists ex) domesticated animals Ecosys engineers (responsible 4 massive ∆s 2 biotic & abiotic environment) Understand human impact on ecosys, help conserve resources, maintain ecosys service, develop healthy sustainable societies
consequences of greenhouse effect
Consequence: melting sea ice, warming temp, ocean acidification
Recognize the diversity of consumer-resource interactions and their effects on populations
Consumer-resource interactions: fundamental ecological relationship between species, organize biological communities into food chains; include predator-prey, herbivore-plant, parasite-host. Competition: two consumers share the same resource, each reduces the availability of resources of the other. Mutualism: interactions benefit both species (pollinator-plant) Commensalism: benefit one, but do no harm on another (bird nests on a tree) Amensalism: elephant crushes a grasshopper under foot.
Describe how the distribution of global biodiversity is influenced by solar radiation and air circulation patters
Cool, dry air in the upper atmosphere tends to fall near 30º, absorbing moisture as it warms, which is why deserts form around 30ºMore variant temperatures in higher latitudesPrecipitation and solar radiation are highest and most consistent at the equator → high rates of primary production
Which of the answer choices is false concerning the development of dead zones in coastal waters, for example, the dead zone in the Gulf of Mexico?
Dead zones in coastal waters of the oceans have been a common occurrence for many thousands of years.
• Evaluate the relationship between life-history strategies and population growth.
Different species have very different life-histories in terms of survivorship between life stages and general life expectancies. life history strategies make the population growth differ; pop growth sprout w/ r strategists at beginning Life history strategies depend on available resources. Some species can vary their strategy depending on the environment. Sometimes it can be more effective to have less eggs with more nutrients or more eggs with less nutrients. There are many tradeoffs including energy, time, resources, space, etc.
Keystone species:
Disproportionately large effect on its community relative 2 its abundance Often provide control on pop size of another species Impacts community across multiple trophic lvl Remove keystone→ disproportionate impact on other species
Predict how resource limitations force life-history tradeoffs
Each individual must devote some of its available food and energy intake to growth, some to the maintenance of cells and tissues, and some to reproduction (lots of tradeoffs)Ex. Lizards adjust the number and size of eggs depending on conditions in the environmentLarger eggs require more resources but provide better resources to offspring, who grow big and are better able to fend for themselvesBut if there are a lot of predators, than laying many smaller eggs might be better
Explain how evolution drives ecological interactions (i.e., intraspecific competition, consumer-resource interactions and arms races, symbiotic relationships and coevolution, etc.).
Ecological interactions drive evolution?The organism that navigates ecological interactions in the most efficient way will have a greater chance of survival → more offspring → trait in many generations → evolution Predation: From evolution point of view, resource organisms should develop many tactics to avoid being eaten (for consumer-resource relationships). Consumers (like predators) should develop better ways to hunt prey. Plants: produce thorns and defensive chemicals that dissuade herbivore. Animals: hide or seek refuge in a safe microhabitats; produce foul-smelling or stinging chemical secretions (scorpions) to dissuade predators; armored body covering (armadillos). Mutualism: symbiosis (obligate) Competition: Either goes extinct, or resource partitioning to lessen competition
Explain how biotic factors determine the distinction between fundamental and realized niches.
Ecological niche: Role of species in ecosystemFundamental niche: Niche a species could occupy with out competitorsRealized niche: Niche a species actually occupies, due to competition of space/resources (biotic factors=interspecific competition
competitive exclusion
Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same timeIs 1 way fundamental niche reduce 2 smaller realized niche Can cause local extinction of 1 of 2 specie
• Define ecology, and understand how abiotic and biotic interactions drive pattern and process at different organizational levels (individuals to ecosystems).
Ecology - the study of how organisms interact with each other and their physical environments Biotic and abiotic factors determine the distribution and abundance of organisms Ecological interactions in the short term affect long-term evolution of traits
• Define ecosystem services
Ecosystem Services: benefits to humans provided by the natural environment and from healthy ecosystems
• Explain energy flow in food webs and how this gives rise to biomass pyramids
Energy flows up the food web and only about 10% of energy and biomass is transferred up a level (ie 90% of energy is lost)
describe CO2 oscillations
Except @ equator, CO2 lvls decline in N. summer & inc in N. winter bc more plants in N & to below photosynthesis=higher rate in summer, lower in winter (respiration=constant)
Explain how solar radiation is unevenly distributed across the globe
Explain how solar radiation is unevenly distributed across the globe
• Identify factors influencing population growth, and carrying capacity
Exponential growth is unstable because the environment cannot sustain an infinite amount of animals Determinants of distribution: abiotic (organisms need specific environments) and biotic (interacting with other organisms) Carrying capacity determinants - how many animals the environment can sustain Same determinants as distribution Also includes interactions with other animals (mutualism, competition, etc)
T or F: An increased rate of photosynthesis is the most likely explanation as to why atmospheric CO2 levels appear lowest during glacial periods of Earth's history.
F: During glacial periods, large amounts of carbon are incorporated into the ocean as sediments.true
If having large numbers of offspring results in high fitness, why do females of all species not have very large numbers of offspring?
Female reproduction is limited by the amount of energy a female can devote to reproduction in any one season
Predict the effects of redundancy on an ecosystem
Functionally redundant ecosystems are more resilient to change.Diverse ecosystems are functionally redundant, and therefore more resilient.Biodiversity leads to ecological resilience! More redundancy allows for community and ecosystem stability. It gives persistence when faced with disturbance => more trophic levels and more species at each trophic level Resilience: Ability to resist or recover quickly from disturbance => supports approximately the same species before and after the disturbance
Differentiate between fundamental and realized niche
Fundamental niche - full range of habitats that a species could occupy (climate, food resources etc)Realized niche - the niche that the species actually occupies due to interaction with other species (competition)
Define functional redundancy in the context of an ecosystem
In ecology, functional equivalence (or functional redundancy) is the ecological phenomena that multiple species representing a variety of taxonomic groups can share similar, if not identical, roles in ecosystem functionality (e.g., nitrogen fixers, algae scrapers, scavengers).Ex: Plant-pollinator species, plant-animal seed dispersal
Nutrients from croplands are carried by the Mississippi River into the Gulf of Mexico. If nutrients are good for growth, why are scientists concerned about this nutrient influx?
Higher productivity may result in increased respiration by bacteria feeding on sinking algal material, depleting oxygen within gulf waters.
dead zone
In a body of water, an area with extremely low oxygen concentration and very little life bc of bacteria that deplete oxygen by consuming algae
• Explain what information is exhibited in a survivorship curve
In a survivorship curve we see the changes in survival probability over an organism's life-span
Evaluate the evidence for anthropogenic climate change and how it relates to the long-term vs. short-term carbon cycles
Humans are burning fossil fuels, which turns long-term carbon into short term carbon, increasing atmospheric carbon
The common mud turtle experiences relatively uniform mortality rates throughout its life. It exhibits Type _____ survivorship.
II
When sea turtle eggs hatch, predators gather, and mortality among the hatchlings is extremely high. Once turtles reach adult size, they can live for decades. This is an example of a Type _____ survivorship curve.
III In Type III survivorship curves, many offspring are produced, but few survive to old age.
how can carrying capacity chang over time?
Inc of resources (like food/space) can inc carrying capacity 4 pop & vice versa Predation & parasitism can reduce pop size below k, but can't ∆ k itself
Explain how diversity can affect primary productivity
Increasing the number of species significantly increased the amount of primary production
Describe traits commonly exhibited by invasive species and their effects on native flora and fauna
Invasive species compete strongly with native species and have no predators so they easily take over and can force native species to go extinct
Consider the image. In the example of the giant kelp forests on the Pacific coast, a rise in the otter population would have what effect on the kelp populations?
Kelp populations would increase due to a decrease in sea urchins. Otters feed on urchins, so urchin populations will decrease. Sea urchins feed on kelp holdfasts. Fewer urchins means that less kelp will be consumed, and the kelp population can increase.
Differentiate between logistic and exponential population growth
Logistic growth - growth that is at first exponential and then levels out (how a population grows due to resource constraints) Exponential growth - growth that rapidly increases and continues increasing (how a population grows without resource constraints)
• Relate carrying capacity to logistic population growth
Logistic population growth levels out at the carrying capacity, which the size of a population that the environment can withstand.
Justify how the loss of species may impact ecosystems
Loss of species makes ecosystem more vulnerable to disturbance, it it will have less resilience and it cannot recover quickly from disturbance
Why are microorganisms such as fungi, bacteria, and archaeons so important to the carbon cycle?
Many of these microorganisms generate carbon dioxide, making it available for primary producers
Define metapopulation
Metapopulation - group of populations linked by corridors
how methane added 2 atmoshprer
Methane lvl inc due to inc cattle production (gut) and rice paddies Thawing permafrost @ higher latitude also release methane trapped in soil
how do species respond 2 climate ∆?
Migrate 2 more favorable place Adapte 2 inc acidification Lose abundance or become locally extinct
What are the causes and consequences of eutrophication?
N or P based fertilizer runoff into water, and cyanobacteria and algae grow and give nutrients to aquatic bacteria who deplete water of O2 from aerobic respiration
• Explain why exponential population growth is unsustainable
bc carrying capactiy- habitat can only support certain # of individuals
How is atmospheric oxygen linked to the carbon cycle?
More photosynthesis leads to more oxygen in the atmosphere and oceans. Higher rates of photosynthesis result in the release of more oxygen into the atmosphere. Organisms with aerobic metabolisms use the oxygen and release carbon dioxide.
Classify the types of interspecific interactions between species
Mutualism - actions benefit one another Commensalism - one partner benefits, and the other experiences no effects Parasitism - one species benefits, while the other suffer sCompetition - both species suffer
Predict the effects of interspecific interactions on the abundance for species involved in the interaction
Mutualism increases carrying capacity Antagonistic interactions (competition) lowers carrying capacity competition: If it is the lesser competitor, in the long run they can go extinct if the other species is the better competitor. The better competitor will take longer for it to reach its carrying capacity
ways conservation biologists protect environemnt
National park reserve- 1) protect habitat area 2) provide managed area w/o overexploitation & pollution 3) buffer against invasive species Bigger is better reserve= 1 large reserve>4 smaller reserve round/square=better bc min edge effect corridors=routes 4 migration Climate ∆= new conservation challenge
invasive species introduced via
Natural colonization, human transported (aesthetics, agriculture, hunting, species control, erosion control, accidental)
greenhouse effect
Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases
What is generally true about biomass and energy as we move from one trophic level to the next?
Not all energy is transferred to the next trophic level. As energy is transferred from one trophic level to the next, some is lost to heat, work, and general inefficiency of consumers. This results in less energy available at each trophic level as you move up the trophic pyramid.
exponential growth equation
Nt=N0e^rt
So-called "dead zones" in coastal oceans are associated with nutrient runoff and oxygen-depleted bottom waters. What causes the oxygen depletion?
Nutrient runoff causes algae and cyanobacteria populations to grow. When they die, they are consumed by heterotrophic bacteria that consume oxygen via aerobic respiration.
abiotic features of environment
Org tend to adapt 2 specific range of physical conditions
• Evaluate the effects of over-exploitation on the evolution of life history
Over-exploitation → dramatic changes in species population/habitat → messes up ecosystem and can affect other animals in the food web
Identify common threats to biodiversity
Over-exploitationHabitat lossInvasive speciesPollutionClimate change
Recall that during the Paleozoic Era, atmospheric CO2 levels decreased. Why?
Photosynthetic, woody plants first appeared during this period.
• Define the term population
Population - members of a population living in a certain area
Photic zone:
Portion of the marine biome that is shallow enough for sunlight to penetrate. 200m
Intertidal
Portion of the shoreline that lies between the high and low tide lines
Differentiate between primary and secondary succession.
Primary succession - small plants and animals come first (r-strategists), who are able to survive in less stable environmentsSecondary succession - larger animals and plants (K-strategists), who need a more stable environmentCan lead to a climax community (little further change in species composition)
Differentiate between r- and K-strategists
R-strategists - have a lot of offspring and have less parental investment K-strategists - have few offspring but have a lot of parental investment
Which of the statements explains how an oxygen-rich atmosphere became possible on Earth?
Rates of oxygen consumption are lower than rates of photosynthesis.
Ecology
Scientific study of interactions among organisms and between organisms and their environment
Compare and contrast long-term versus short-term carbon cycling
Short term carbon cycling - exchanges over days, years, and decades driven by the biological processes of photosynthesis and respiration, and altered in recent times by human activities.Photosynthesis and respiration are key processes in short-term carbon cycling. Humans also contribute by burning fossil fuels. Long term carbon cycling - physical processes, including volcanism and climate change, linking Earth's physical and biological processesBurning fossil fuels moves carbon from long-term to short-term
Evaluate the role of density dependence in regulating population growth.
Some factors are density dependent, meaning that they are affected by density, such as disease, reduction of resources, increased competition, crowding, etc. These all contribute to regulating population size
Articulate how interspecific competition can lead to coexistence and/or competitive exclusion, and predict how competition influences species distributions.
Some species learn to coexist by modifying their niches (resource partitioning) Competitive exclusion leads to one species abandoning niche at that location (species may migrate) competition doe not change K, but prevents population sizes from reaching K Causes one, the lesser competitor to go extinctcauses other, the competitive advantage one, to reach carrying capacity at a slower rate
Differentiate between species diversity and species richness
Species diversity is defined as the number of species and abundance of each species that live in a particular location. Species richness is the number of different species represented in an ecological community, landscape or region. Species richness is simply a count of species, and it does not take into account the abundances of the species or their relative abundance distributions
Latitude diversity gradient:
Species diversity is generally greatest @ low latitudes (equator) & dec towards high latitudes (N/S Pole)
species area relationship
Species-area relationship: S=CA^x s=# species @ equilibrium c= math constant A=habitat area x= determined exponent that relates A to S and .1<X<.4
age structure chart
Stationary: circle like Rapidly expanding: ∆ with curved sides like an exponential graph Expanding: ∆ shape
what govern rate of primary production
Sunlight (earth tilt), water (photosynthesis), nutrient (less N in forest and ocean, other ocean less P and Fe)
If Earth had no oceans, would temperatures at the equator be hotter or colder than they are now?
Temperatures would be hotter. Water holds a lot of heat. If there were no oceans, then the heat typically held in ocean water would be spread across all the land masses.
Biodiversity
The amount of biological or living diversity per unit area. It includes the concepts of species diversity, habitat diversity and genetic diversity.
A farmer treats the soil with a fertilizer containing an antibiotic that kills a bacterial plant pathogen. The crop does not grow well. What most likely happened?
The antibiotic also killed the symbiotic bacteria that fix nitrogen for the plants. Without a source of nitrogen, the plants did not grow well. Many plants depend on symbiotic bacteria to fix atmospheric nitrogen into a form plants can absorb and use. Antibiotics sometimes have nonspecific effects and can kill surrounding soil bacteria in addition to the bacterial plant pathogen. If the symbiotic bacteria of the crop plant were killed by the antibiotic, then the plants would lose their source of nitrogen and not grow well.
A gardener treats his plants with pesticides, killing all the aphids that are on the plants. Once the aphids die, what likely happens to the mutualistic bacteria inhabiting their digestive tracts?
The bacteria would likely die without their mutualistic aphids, as this is an example of an obligate relationship.
Explain how biotic factors determine the distinction between fundamental and realized niches
The difference between fundamental and realized niche is the difference in biotic factors. Fundamental accounts for abiotic factors, but not all biotic factors, whereas realized accounts for biotic factors, such as competition between species
The expanding base of a population pyramid over time indicates which of the following?
The number of younger individuals in the population is increasing.
Recognize the causes and impacts of inefficient energy transfer
The problem that occurs during the transfers is a massive amount of lost energy resulting in each transfer only resulting in 10% of the previous energy, this can result in higher levels in the energy chain struggling to survive if the lower levels of the chain cannot supply enough required energy the whole community will fail
Biologists who study biodiversity describe new species and monitor species of which we are aware. Why is the study of biodiversity important in the Anthropocene?
The study of biodiversity is important because it helps quantify the effects of human actions on changes in the traits of many populations (size, density, and distribution)
what causes seasons
Tilt of earth= seasonality; positive revolution around sun=high latitude seasonally N. hemisphere receives more solar E/unit area in July than other times of yr (S=Jan)
T or F: The long-term and short-term carbon cycles are connected by the fact that some of the carbon contained in C6H12O6 (or other organic molecules) in plants is incorporated into sedimentary rocks or oil; carbon in sedimentary rock and oil is not immediately cycled back to the atmosphere.
True When plants decompose, some of the carbon will be returned to the atmosphere. However, some of the carbon will be incorporated into oil or sedimentary rocks.
Explain why vegetation is the most commonly used proxy to characterize terrestrial biodiversity
Vegetation consists of primary producers, which are necessary for increased biodiversity, since they are the bottom of the food web
describe warm vs cold air
Warm air=less dense than cold air=rise in atmosphere & cools as rise Rise then spread, low to high latitude Coriolis effect: cooling air move slower than equator; wind moving N/S seen 2 deflect R in N Hemisphere & L w/ S. Hemisphere Cool dense water sink beneath warmer water & move toward equator War air carry more water vapor than cold air carry; as air cools, vapor condenses & rains
Net human inputs to atmospheric carbon dioxide per year are estimated at approximately 8.8 gigatons. This is considerably less than the 209 gigatons of carbon dioxide added to the atmosphere by the respiration of all marine and terrestrial organisms. Given this, should we be concerned?
We should be concerned because this addition is not counterbalanced by photosynthesis or other removal processes and therefore can accumulate or build in the atmosphere over many years leading to climate change.
Compare and contrast climate versus weather
Weather reflects short-term conditions of the atmosphere while climate is the average daily weather for an extended period of time at a certain location
3 features of ecology
Where org found (distribution) How many occur there (abundance) Y occur where they do (causation)
Which of the actual (i.e., real) products of biological activity is not likely to be a source of the increases in greenhouse gases observed in recent history? A) carbon dioxide produced as a result of aerobic cellular respiration in living organisms B) increases in the amount of water vapor the atmosphere can hold (or relative humidity) at higher global temperatures C) carbon dioxide produced by use of fossil fuels in automobiles, heating and cooling, and industry
a
Tropical rainforest
a broadleaf evergreen forest found in wet and hot regions near the equator.
zoonotic disease
a disease communicable from animals to humans under natural conditions; also know as zoonosis
Keeling curve
a graph made over the span of 50 years that shows the increase of carbon dioxide
Biomes
a large naturally occurring community of flora and fauna occupying a major habitat, e.g., forest or tundra.
Recall that photosynthetic rates remain relatively constant in regions near the equator. Imagine that tropical environments persist throughout Earth's northern and southern hemispheres; that is, that Earth's entire climate mirrors that near the equator. If Keeling had collected his atmospheric CO2 data on such an Earth, what would you expect the Keeling Curve to look like?
a straight line sloping upward, indicating that atmospheric CO2 levels would not seasonally oscillate, but would increase over time
Give an example of an obligate mutualism. Why is it considered obligat
aphids and bacteria that colonize them. neither species survive w/o other
Lemmings affect many other species in the Bylot Island community. Why are lemmings not considered a keystone species?
bc effect bc of abundance, not bc of their role
On an annual basis, what is the net result of the contributions/removals of CO2 from the atmosphere due to global photosynthesis and respiration (both terrestrial and marine)?
approximately 3 gT yr-1 decrease
In a metapopulation, source populations are species that are likely to have more individuals immigrating to habitat patches than other species. This means that source populations:
are likely to occupy the largest suitable ecological patch.
What defines the niche of a species
abiotic factors like soil chem and climate and biotic like b/w species
Ecosystem engineers
actively shape physical environment, create habitat 4 others
realized niche
actual range of habitats occupied by a species Invasive species show realized niche often smaller than fundamental predation & resource availability
Rates of respiration are known to vary positively with temperature. As increasing CO2 causes temperatures at the Earth's surface to rise, would changing rates of respiration tend to exacerbate or dampen this rise?
add CO2-rise
What is the source of the elevated nutrients in the water that cause the formation of dead zones in the Gulf of Mexico?
agricultural runoff from much of the central United States
Which path will a nitrogen atom most likely travel from nitrogen (N2) in the atmosphere to amino acids in the cell of a secondary consumer?
air > bacteria > plant > primary consumer > secondary consumer
Which path will a carbon atom most likely travel from CO2 in the atmosphere to glucose in the cell of a secondary consumer?
air > plant > primary consumer > secondary consumer
parasites feed on
all lvls of sys
The graph in Fig. 46.3 suggests that human activities have influenced CO2 levels in the atmosphere. What is one line of evidence that lends support to this hypothesis
all source have diff ratio of diff types of C; measure ratio to determine which one adding to atmosphere
If a scientist wanted to determine if a forest environment had been polluted, which group of organisms typically would be the best indicator for the presence of pollutants
amphibians Many pollutants end up in the water supply. Because amphibians have part of their life cycle in the water, and exchange gases through their skin, they are susceptible to changes in water quality. Observing changes in amphibian population status can serve as an indicator of pollution.
The bacterial species Staphylococcus aureus is found on the skin and in the nasal passages of about 20% of the human population. In healthy individuals, S. aureus is benign (does not cause harm) in these locations. However, if it is introduced into the bloodstream through, for example, a wound, it can make a person gravely ill. Thus, the ecological relationship of S. aureus with a human:
an be commensal or antagonistic. The relationship of this bacterium can either be neutral, where they are only living on a person. When the conditions change, the bacterium can be harmful. It's interaction with humans is determined by the location where S. aureus is found.
Agricultural runoff into a pond can result in additional nutrient input. Which scenario is likely to happen in response to additional nutrient input?
an explosion of algal growth that leads to explosive bacterial growth
Trophic lvls
an org's place on the food web) Primary producer: photosynthesis, 1st trophic lvl Primary consumer: heterotrophs feed on above Secondary consumer: heterotrophs feed on above Decomposer-fungi & bacteria that feed on all trophic lvls
how is temp controlled
angle that solar radiation strikes the surface
Theory island biogeography
as size habitable area dec, species diversity within habitat dec
obligate
association where 1/both sides mutualism can't survive w/o other
exponential growth
assume no constraint on pop size & growth rate is constant; pop grows in proportion to # of ind
Why are equatorial latitudes generally wet, but land masses at about the 23 to 30 degrees north and south latitudes generally dry?
at equator air warms and rises, and as rise it cools, and water vapor condense and fall as rain. opposite for the other; as air away from equator it cools, denser and descends and warms as it goes, takes up water vapor
Reforestation efforts around the world contribute to increased uptake of CO2 from the atmosphere and conversion to organic matter. Deforestation, on the other hand, typically by clearing and burning of natural vegetation, results in added CO2 in the atmosphere. What is the current estimate of the annual net balance between these two processes?
atmospheric increase by 1.0 gT yr-1
Ecological footprint concept:
attempt 2 quantify ind claims on global resource by add up all E, food, material, & services we used, and estimate how much land req 2 provide those resources
Which of the answer choices is false? A) The Earth radiates heat energy back to the atmosphere. B) The greenhouse gases in the atmosphere have all come from human activity. C) Light energy from the sun warms the surface of the Earth's continents and the ocean. D) Approximately 50% of the sun's light energy does not reach the surface of the Earth. E) Much of the heat that is lost from the Earth's surfaces is re-radiated back into the atmosphere by greenhouse gases.
b
Which of the answer choices is expected to reduce competition among individuals of different species? A) a shortened mating season B) resource partitioning C) a decrease in the carrying capacity of an environment D) destruction of habitat space E) the disappearance of a predator from an area
b The division of resources in an area allows for coexistence of multiple species in an area, instead of one species outcompeting all the others in the area.
Tropical rainforests have high species richness, but low density. In deciduous forests the pattern is the opposite. Which of the statements is not a plausible explanation for this pattern? A) Many deciduous tree species are pollinated by wind, so individuals must be more closely spaced to one another for fertilization to occur. B) There are fewer species in temperate regions because the number of trees per hectare is lower than in tropical rainforests . C) Organisms that are adapted to the variability in higher latitudes are able to achieve higher population sizes. D) Because there are fewer organisms that can adapt to higher latitudes, there are fewer "pest" species that could easily move between trees in close proximity
b Trees can still achieve high density at higher latitudes.`
Which organisms can carry out nitrogen fixation?
bacteria
Why are biologists interested in age structures of populations?
because age structures provide information that allows the estimation of a population's potential for future growth
When would a researcher be most likely to observe resource partitioning?
between two sympatric species that eat similar-sized seeds
ecosystem services depend on
biodiversity
Temperate grassland:
biome characterized by deep, nutrient-rich soil that supports many grass species
What four processes affect population size?
birth rate, death rate, immigration, emmigration
The carrying capacity for a population of birds limited to a specific forest area should increase if you increase:
both food availabilyt and nesting sites
When two species compete for resources the fitness of:
both species will decline. Competition requires an expenditure of energy from competitors. The expenditure of energy means there is less energy available, or fewer resources, to devote to reproduction. This would translate into a decrease in the number of offspring produced and lowered fitness.
Benefits associated with symbiotic relationships might include all of these except: A) assistance in reproduction. B) competitive exclusion. C) .protection. D) shelter. E)nutrients. Score: 1 of 1
c Competitive exclusion is not a symbiotic interaction. Symbiotic interactions benefit one or both members. Competitive exclusion would result in a fitness reduction for at least one of the competitors because energy expended competing could not be devoted to other activities, such as reproduction
Which scenario might slow population growth? Select all that apply. A) agricultural runoff providing additional nutrient resources B) adaptation that allows the population to gather nutrients more efficiently C) competition within species for the same resources D) growing population size reduces the amount of space available as a proper habitat
c and d
Which factors contribute most to intraspecific competition? A) a species' fundamental niche and abiotic surroundings B )predation and parasitism C) a species' rate of reproduction and the carrying capacity of the environment D).mutualistic relationships E) predator population size
cAs a population increases in size, it approaches carrying capacity. The more individuals there are in the population, the fewer resources that are available for each individual in that population, which, in turn, negatively impacts their chances of surviving to reproduce
source
can "rescue" sink pops, either through recolonization or dispersal to a sink
sink
can blink out
What are two ways organisms can respond to changes in CO2 levels and temperatures?
can modify behavior, or move
How can a physical disturbance, such as a drought, affect community composition?
can reduce pop size not equipped for drought, let new species enter and colonize, can limit species diversity
A species that is involved in a facultative mutualism with another:
can utilize different resources outside of the mutualism.
• Describe a climax community and how they are the result of disturbance and succession
climax community: A mature assembly, a final stage in succession, in which there is little further change in species composition. Has k-strategists, usually the end of succession succession: The replacement of species by other species over time.
symbioses
close interaction b/w species (antagonisms or mutualisms) that've evolved over long periods of time When interaction b/w species drives reciprocal adaptations in both participants, possibility 4 long term coevolution bc each side descendants r associated w/ each other (inc interdependence) General association (no b/w specific species) can also b beneficial
• Relate species diversity on islands to rates of colonization and extinction
closer to mainland= higher colonization rate, bigger island= less extinction
When both participants in a species' interaction develop adaptations in direct response to one another, this could progress into all of the outcomes except:
coevolution
Alpine
cold, more temp vary, j below alt where snow persist all yr, wind, cold, little plants grow low bc UV. grasses=lots, goats, llamas
Tundra
coldest, little plant, low precipitation, evaporation, plant diversity & have waterlogged soil, permanent ice below soil
Primary succession:
colonization of new/previously uninhabited land
Which factors determine the diversity of species on a habitat island? What is the relevance of these factors in managing the habitat of an endangered species?
colonization/extinction rate.s conservation efforst of endangered species
Niche
combo of species' physical habitat & ecological role in that habitat; where org occur & what they do there
The human body has about 10 bacterial cells for every eukaryotic cell. Bacteria coat our skin, gut, and mouth. Also present are protists, archaeans, and viruses. Collectively, these organisms are our microbiota. For most members of our microbiota, our body provides their environment, or space to live. They, in turn, have no effect on us. This is an example of:
commensalism. When one organism requires another to live but the other is unaffected, their relationship is defined as a commensal symbiotic relationship
The sum total of populations of different species that live in a given area is called a(n):
community
Intraspecific comp:
comp among ind of single species due to tension b/w intrinsic rate of inc & carrying capacity; always density-dependent
common characteristics of invasive species
competes strongly w/ natives, no predators (disease in new location), can alter ecosys, may push natives 2 extinction
Which of the answer choices is a type of interaction in which both parties are harmed?
competition
What is the difference between competitive exclusion and resource partitioning
competitive exclusion-ongoing comp,--> 1 species change niche. resource partiion-species evolve 2 use diff resource
In the late 1960s, Robert Paine conducted landmark studies on diversity in the rocky intertidal zone, comparing the species diversity in control plots with diversity in experimental plots from which he removed the top predator, sea stars. After 5 years, 15 species of intertidal invertebrates lived in the control plots, while the experimental plots were dominated by only two species, one mussel and one barnacle. The process most likely responsible for the loss of species diversity in the experimental plots was:
competitive exclusion. Within the experimental plot, the removal of the top predator allowed more individuals of the remaining species to survive. As the better competitors of those remaining species gained more resources, their population sizes grew and fewer resources were available for the less competitive species. The species that were not as efficient at competing for resources in the plot went locally extinct, or left the area, because they could not acquire the resources necessary to survive there
Temperate coniferous forest
coniferous trees (have year-round needles); warm, rainy summer; cool winter
primary consumer
consume primary producer- herbivore/grazer
herbivory
consumption plant parts, benefits herbivorous animal w/ nutrients, harms plants by affect product of photosynthesis
E must b
continually harvcested by plants bc no cycle
What is a trade-off in physiological functions? Give an example
contribute more energy to 1 function than other. like plants produce more seeds than thorns
The high specific heat of water means that land masses near the equator are___ than predicted
cooler than predicted because of all the heat carried by ocean waters from low to high latitudes. Water can carry more heat than air. The ocean current moves warm water away from the equator towards the poles and is replaced by cooler water from deeper depths.
Why are corridors important to the health of local populations?
corridors allow movement and recolonization
What are some of the costs and benefits to an apple tree and to the honeybee that pollinates it? Which kind of interaction is this?
cost apple tree- investment in flowers, benefit is pollination. cost to bees in energy in pollination, benefit is food. mutualism
how to estimate biodiversity
count plant; plant x 4=animal species
Which of the answer choices is not an example of a greenhouse gas? A) water vapor B) methane C) carbon dioxide D) oxygen
d
logistic growth equation
dN/dt=r((k-N)/k)N
weather
daily weather
If plate tectonic processes form a chain of high mountains, would you expect atmospheric CO2 to increase or decrease?
dec; inc mtn=inc chem weathering and erosion-dec CO2Rates of respiration are known to vary positively with temperature.
Moderate temperatures and precipitation, as well as nutrient-rich soil due to annual leaf fall, characterize this biome.
deciduous forest
Which group in a food web is responsible for returning inorganic compounds back to the environment?
decomposer
A population of pocket gophers shows logistic growth. As the population approaches carrying capacity (K), the number of individuals added to the population per unit of time will:
decrease
assisted migration
deliberate transplantation of plant pop from existing habitats 2 more favorable ones 4 growth
Which process(es) return nitrogen (N2) directly back to the atmosphere? Select all that apply.
denitrification, anammox
In terrestrial ecosystems, nitrogen is returned to the atmosphere by:
denitrifying bacteria
Density dependent factors:
depend on density of pop ex) competition & predation, disease & parasites, territoriality, intrisic factors (physiological), toxic wastes Density dependent pop growth : ∆N=r(N)N Intraspecific comp (within species) 4 resources can result in natural selection where same ind have genetic mutation that give advantage over others Interspecific (b/w species) comp can result in inc/dec pop size
what determines sensitivity of reservoirs
depend on their size & material movements
Name two density-dependent and two density-independent factors that can limit the size of a population.
dependent- inter/intra specific comp. independent: weather and temp
Which of these biomes receives the least amount of rainfall, and therefore has low primary production, nutrient-poor soil, and plant species that are adapted for water storage?
desert
In deeper waters, nutrients primarily come from:
detritus sinking from more productive shallower waters.
If photosynthetic organisms all gain carbon and energy in much the same way, how do diverse photoautotrophs persist in ecosystems?
diff species adapt 2 diff environmental conditions
Increased phosphate levels in the Everglades has led to:
displacement of native plants by phosphate-loving introduced plants
Species diversity=highest when
disturbance is freq enough 2 inhibit comp, but not limit # of species that tolerate environment
w/ similar biomes in diff places
dominant plant look alike but no close relation (convergence
The bacterial species Staphylococus aureus is found on the skin and in the nasal passages of about 20% of the human population. It can survive on polyester for 3 months and can also infect cows and chickens. Thus, its relationship with humans is:
facultative. Facultative relationships are those where one species is living in close association with another species or living independently or with a host. Because S. aureus can infect other organisms and live on its own for short periods of time, it satisfies the conditions for a facultative relationship with humans. Score: 1 of 1
shifts in phenology can result in
earlier plant/animal phenology; mismatch
You decide to plant a garden in your backyard. You dig up a strip of grass in a sunny spot. When you have finished digging up the grass, but you haven't planted anything, you have created a(n) _____ in the lawn.
ecological disturbance After a disturbance, none of the species' composition in the area is changed. Removing the grass and leaving only soil would result in a secondary successional pathway for the community. That secondary pathway is the soil and its nutrients.
as standard of living increases,
ecological footprint inc
Why does the mean "ecological footprint" of a country's citizens increase as its standard of living increases?
ecological footprint= amount of land need supply all energy and resources a person uses
A community of organisms and the physical environment it occupies are known together as a(n): species.community.ecosystem.population.
ecosystem
Which of the answer choices is responsible for the increased growth of algae in the dead zones?
elevated phosphorous and nitrogen in the water
ind need ___ to reproduce
energy
t or f: Most of Earth's primary production comes from tropical rainforests.
false
biodiversity highest at
equator
In marine ecosystems phosphorus is added to the ecosystem primarily from
erosion of rocks on land
Nitrogen fertilizer is added to farmland to improve crop yield and quality. While farmers are working to reduce the amount of runoff from fields, some of the fertilizer enters streams. The streams flow into the Mississippi River and ultimately into the Gulf of Mexico where the added nitrogen supports increased algal and cyanobacterial blooms. The addition of nutrients to water systems, which causes increased growth of algae and cyanobacteria, is termed:
eutrophication
Nitrogen runoff leads to large increases in the populations of algae and cyanobacteria in lakes and oceans in a process known as:
eutrophication
When a population is small relative to its carrying capacity, its growth will be:
exponential
t or f; The sequence of types of species that colonize a recently disturbed area through succession is unpredictable.
f
t or f: K-strategists tend to inhabit "unpredictable" environments and also have population densities near the carrying capacity of an environment.
false Population sizes of K-strategists often are close to carrying capacity. However, r-strategists are more likely to be successful in unpredictable habitats. More offspring produced from sexual reproduction keeps variation high due to independent assortment and recombination. The variation in offspring increases the probability of survivorship of those offspring with traits that will be selected for in unpredictable environments
t or f: If all of the tertiary consumers were removed from an environment, the associated food web, and thus the carbon cycle, would collapse.
false The food web would likely be greatly altered, and the biomass at each trophic level would change. If tertiary consumers were removed, there would be an increase in secondary consumers. The secondary consumers would then decimate primary consumer populations, and primary producers would increase. The carbon cycle would not collapse, as it is a global and not a local cycle.
Primary producer
fix inorganic C into organic molecules that feed other orgs in community
describe N cycle
fixation by bacteria in soils/water, then Nitrate taken by primary producer incorporate into biomass via assimilation ammonification=decomposer return to soil Bacteria carry denitrification or anammox to oxidize back into air N fix by human=double amount fix by natural process
t or f: Predator/prey relationships are always linear, with one species affecting only one other in the community.
flase
best known biodiversity
flowers
The rate of exchange of carbon between the atmosphere and the oceans represents a carbon
flux
A _____ depicts the flow of carbon through an ecosystem, whereas a _____ depicts the transfer of energy.
food web, trophic pyramid
river
freshwater, moving water, shape ∆, lots O2, phytoplankton, insects, invertebrates, fish
Fundamental niche
full range of climate conditions & food resources that permit ind in a species 2 live Ability 2 disperse 2 other areas Niche species COULD occupy w/o competition
diverse ecosystems r
functionally redundatn
Imagine that a scientist takes a group of Anolis lizards and introduces them into an enclosure at a research facility in continental South America. He notes that the lizards thrive in this new environment. The fact that Anolis lizards could survive in habitats outside of the Caribbean is a reflection of their ____ niche; their _____ niche is determined by their ability to disperse to other areas as well as predation and resource availability.
fundamental, realized
Genetic variation within species is important to conservation because:
genetic variation provides a means by which natural selection can "act" when the environment changes. When there is variation in a population, then it is possible for natural selection to select for individuals with traits that will increase fitness in a changing environment.
Characteristic vegetation map from plant form correlation w/
global temp & rainfall→ map Earth's terrestrial biomes
What is the difference between global warming and the greenhouse effect?
global warming is measured effect on Earth's warmth, greenhouse effect contribute to global warming
Describe the general pattern of diversity from the equator to the poles. Provide two hypotheses to explain this pattern of diversity.
greater species diversity near equator bc higher latitude= extreme seasonal changes in temp
Cohort
group defined as ind born @ a given time
Metapopulation
group of ind pops occupying separate patches that're connected via dispersal linked by immigrants
Consumer
heterotrophs; other feeder; get C from food they eat
A dead zone has been documented off the coast of Oregon. Which of the options could contribute to the formation of the dead zone?
high nitrogen levels in the area
edge effect
how habitat on edge of forest differ from within forest Plants & critters near forest edge often expose 2 more light, more wind, less humidity As edge: habitat ratio smaller, edge effect more prominent May result in metapopulation structure Small pop more vulnerable→ extinct via abiotic factors
Resistance
how much ecosys ∆ as result of disturbance
Ocean acidification-
inc CO2 in ocean cause pH to dec Also carbonate ions dec, make difficult reef to build CaCO3 skeleton
Describe how herbivores can affect the abundances of organisms at higher and lower trophic levels.
inc herbivore inc above, dec herbivore dec above
Which human activities are responsible for almost doubling the amount of fixed nitrogen? Select all that apply.
inc use of agriculture fertilizer, burning of fossil fuels
describe P cycle
incorporated by biomass w/ primary producer→ consumer→ sediments→ surface (upwelling) → tectonic uplife to form mtns
the intrinsic growth rate, r, of a population is measured as 0.05. When not limited by resources, the size of this population should:
increase exponentially over time
If phosphorous concentrations were to suddenly increase in a marine ecosystem, which of the choices would likely occur?
increased primary productivity Carbon is not the only element necessary for growth in organisms. Phosphorous is also required to enable growth. Consider the sugar phosphate backbone in DNA. Cell division cannot occur without phosphate containing nucleotides for DNA replication. Increasing phosphorous concentrations in marine environments increases primary productivity.
Measuring the isotopic composition of atmospheric CO2 shows that the burning of fossil fuels has led to _____ CO2 levels over the last 200 years.
increasing Comparing the ratios of 13C and 12C provides an indication of how atmospheric carbon contributions have changed. Organic matter formed through photosynthesis has the same ratio of 13C to 12C and matches the ratios found in Seuss's measurements. This indicates that the release of carbon from the burning of fossil fuels contributes to the increased amounts of carbon added to the atmosphere.
What are several possible solutions to the problem of feeding a growing human population?
increasing crop yields, more land, genetic engineering
A severe drought is an example of a density-_____ factor that can influence population size. The availability of nest sites is an example of a density-_____ factor.
independent, dependent
Density-independent factors:
influence pop size w/o regard 4 pop density Can cause mortality regardless of pop size ex) natural disaster & unexpected ∆ in temp, severe drought, weather
Which of the answer choices is reflected back to the Earth's surface by greenhouse gases
infrared radiation
Competition
interaction which use mutually needed resource by ind lowers availability of that resource 2 other ind- lose lose
Antagonistic interactions:
interactions where at least 1 participant loses more than gains Interactions involve costs (often in resources) & benefits (usually inc in reproduction) Can b direct (species physically interact) or indirect (like comp 4 food) Benefits r 1 sided; 1 org compete w/ other or consumes it
What do competition, predation, parasitism, and herbivory all have in common?
interactions where at least 1 species harmed
commensalism
interactions which 1 partner benefits & no apparent effect on other
Draw and explain the curve representing changing atmospheric levels of CO2 over the last 400,000 years.
interglacial period CO2 high, glacial period CO2 low
An invasive species:
is any non-native species that becomes established in a new ecosystem.
The maximum number of individuals that a habitat can support:
is carrying capacity
The maximum rate of growth per individual is:
is intrinsic growth rate
habitats
island separated by uninhabitable territory that may b difficult 4 ind 2 cross
A species that has a disproportionately large effect on a community is called a(n) _____ species.
keystone
List three examples of a habitat island. What makes each an island
lake for trout, actual island in ocean, valley surrounded by mtns
Why do patterns of global primary production on land show strong latitudinal variation, whereas primary production in the oceans varies more strongly with distance from shore?
land primary production goverend by temperature and rainfall. ocean by nutrients from shore
risk factor 4 zoonotic disease emergence
land use ∆ (deforestation), intensification of agriculture & livestock production, climate ∆, illegal/poorly regulated wildlife trade
r strategists
large # offspring but few resources 4 support Unpredictable environment, like full of predator Offspring lost w/ small survival care Type III r strategists bc reproduce @ rates approaching rmax (max intrinsic value of inc)
Relate the Law of Tolerance to species' distributions
law of tolerance make sure individuals don't have worldwide distribution- specific parameter individual can exist in
Warm air is _____ dense than cold air, and warm air holds _____ moisture than cold air.
less more
succession sequence
lichens/small photosynthesis plants colonize rock, mosses Small invertebrates form soil Then larger insects/invertebrates/small mammal/sedges/grass Early colonists=r strategists Then sun loving tree (provide shade) Then shade loving tree Stable k-strategists in forest form mature assembly=climax community
Given models of population growth, which model would be the best to use for determining estimated sustainable yield?
logistic Logistic growth implies that there is some limit, carrying capacity, for a population of a certain size. Operating under this constraint would allow determination of the number of resources necessary to maintain a population at carrying capacity. Exponential growth would be continually increasing, with no constraint from a carrying capacity, so there would be no "specific" population size where planning could occur for sustainability.
A population of ten mating pairs of butterflies colonize a new area with no predators and a number of flower species large enough to support a butterfly population of 2000 individuals. Each pair can have 20 offspring per year. For the first 2 years in the new area, the growth curve for this butterfly population will show:
logistic growth because the colonizing population will reach carrying capacity within the first two years.
Draw an exponential growth curve and a logistic growth curve. What accounts for their different shapes?
logistic is sigmoid bc of carrying capacitydue to scarce resource and crowding limits
The _____ cycle deals with geological processes and carbon reservoirs, some of which have been built up or take place over a period of millennia. In contrast, the _____ cycle involves biological processes that are carried out on a daily and/or seasonal basis.
long term carbon; short term carbon
Climate
long-term avg weather ex) avg in march=cold
k strategist
low # offspring but invest reproductive resources Type I Protected better from predator, can compete when young More likely 2 survive till adulthood K bc pop density commonly live near carrying capacity K
Carrying capacity (k)
max # of individuals a habitat can support
How do invasive species affect species diversity of communities and ecosystems?
may outcompete native species 4 resources, or prey on species, diminish their size and diversity
What is the difference between a population and a metapopulation?
metapop is 2+ populations linked by immigration
• Describe characteristics of a metapopulation
metapopulatino connected to others through corridors, and made up of sources and sinks, individuals habitats surrounded by uninhabitable area
A large population made up of smaller populations linked by migration is a:
metapopulation
functionally redundant ecosystems r
more resistant 2 change
Some species of ants "farm" aphids by protecting them from predators. In return, the ants feed on a sugar-rich liquid, called honeydew, secreted by the aphids. The ecological relationship between the ants and the aphids is:
mutualism. Because both species receive a benefit from their association with the other, this relationship is classified as mutualism.
_____ allows populations to adapt to the abiotic and biotic conditions where they live.
natural selection
what lets pop adapt 2 abiotic & biotic omponents
natural selection
Which regions in freshwater or marine biomes would you expect to have the highest productivity?
near surface where sunlight penetrates
Food web:
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem within C cycle
endemic species
new, closely related species that aren't found anywhere else in the world due to populations close 2 each other cross over & breed
Scientists have pointed out that if humans stopped emitting CO2 into the air today, atmospheric CO2 levels would not return to pre-Industrial Revolution levels for hundreds of years. Why is this so?
no change rate of removal
Pelagic biome open water:
no sunlight, most of ocean, plankton, zooplankton, animals less abundant in deep water
What are the products of photosynthesis? Select all that apply.
oxygen, glucose
nWhat basic facts about populations do we need to know to describe them?
number and range, then we calcluate density
While biodiversity includes the number of species in a given area, it also includes:
numbers of different phylogenetic groups.
A mutualism in which the survival of one or both participants is dependent on the other is
obligate
How do marine biomes differ between the surface ocean and the deep seafloor?
ocean surface water bathed w/ light=photosyntheiss- abundant biomass. deep sea support by organic detris from srface. biomass deep sea= low. hydrothermal vent release hydroge, methane, and hydrogen sulfide 2 support animals
trophic lvl
org's typical place in food web; 1st trophic=primary producer
Deep sea biome:
organic debris rain down from surface, limit biomass, hydrothermic vent
biotic features of environment
organisms tend to interact w/ other species
short term carbon cycle
oscillations. biology= annual rhythm of Keeling curve From photosynthesis & respiration C transfers from species to species CO2 removed by photosynthesis ≈CO2 returned by aerobic respiration
corridors important to
patch colonizers (not 2 species that don't use them (cant move))
How does the Red Queen hypothesis apply to interactions of pathogens and antibiotics
pathogens must frequently evolve resistance to antibioitics to stay within its same ecological niche
• Describe changes in per capita growth rate in exponential and logistic growth curves
per capita growth rate changes in logistic-at begin, looks like exponential, then towards end looks like linear, 1/2 k = greatest growth rate
hrough which metabolic process does carbon enter the food web?
photosynthesis
Plant transpiration rate reflect
photosynthesis rate & available soil & water
Why does the coupling of photosynthesis and respiration result in the cycling of carbon?
photosynthesis uses light and CO2 to make glucose, then animals use that and O2 to make CO2
Which of the processes are typically associated with the short-term carbon cycle? Select all that apply.
photosynthesisrespiration
niche determined by
physical (abiotic) factor like climate & soil chem, also by biological (biotic) factor on interaction w/ other species
Topography
physical features of Earth's surface; elevation inc→ climate dec
reservoirs
places C found on Earth- orgs, atmosphere, soil, ocean, sediment growth
What are several possible solutions to the problem of increased atmospheric CO2?
plant more trees w/ reforestation, use alternate energy sources
Which of these is a good predictor of biodiversity in terrestrial ecosystems?
plant species in a community
Prairie dogs are rodents that live in colonies. Black-tailed prairie dog (Cynomys ludovicianus) colonies typically have around 12 adult animals per hectare. What aspect of the population ecology of the black-tailed prairie dog does this statement describe?
population density
Some biologists have suggested that overexploitation in the harvesting of some sharks, which are top predators, has caused drastic changes in marine communities. Which of the outcomes would you expect after removal of a top predator from a community?
population growth of prey species
Sustainable harvest practices in fish populations ensure that:
populations of fish are able to grow and reproduce to replace what is caught
A _____ consists of all the individuals of a given species that live and reproduce in a particular place.
pouplation
Measuring its costs and benefits in terms of energy spent and/or gained, which interaction definitely involves one individual gaining and one individual losing? A) facultative mutualism B) commensalism C) competition D) obligate mutualism E) predation
predation
How can predators influence competition and affect the niches of other species
predator prey on species, let comp w/ prey inc in size.
secondary consumer
predator/scavenger, feed on primary consumer
Organisms that take up inorganic nutrients and convert them to organic molecules such as carbohydrates and proteins are called:
primary producer
The broadest level in a trophic pyramid is primarily composed of:
primary producer
Which of these organisms can incorporate atmospheric carbon directly into C6H12O6, thereby playing a major role in a food web?
primary producer
Consider the list of ten organisms and associated behaviors. I. maple tree II. cow that eats grass III. fungus that breaks down tree bark of dying trees IV. rabbit that eats lettuce V. whale that eats krill (krill eat photosynthetic phytoplankton) VI. hawk that eats mice VII. mouse that eats berries VIII. bacteria that degrades plant cell walls of dead leaves IX. lobster that eats photosynthetic seaweed X. photosynthetic green algae Classify the organisms as primary producers, primary consumers, secondary consumers, and decomposers.
primary producers: I, X; primary consumers: II, IV, VII, IX; secondary consumers: V, VI; decomposers: III, VIII Organisms that carry out photosynthesis can fix inorganic carbon (CO2) into organic molecules. Since organisms I and X can carry out photosynthesis, they are primary producers. Organisms that consume primary producers, such as organisms II, IV, VII, and IX, are primary consumers. Organisms that feed on primary consumers are secondary consumers. Organism V, the whale, feeds on krill, a primary consumer. Krill feeds on the primary producer phytoplankton. Organism VI, the hawk, feeds on mice, a primary consumer. The mouse eats primary producers like grasses, berries, and nuts. Decomposers, such as organisms III and VIII, break down dead tissues and return carbon to the atmosphere. Score: 1 of 1
Lieby's Law of the Minimum:
primary production limited by the nutrient that is least available relative to the needs of primary producers
sustainable development
principal rate @ which use resources should b no higher than rate @ which can be replenished
succession
process of species replacing each other in time in predictable sequence
What is meant by "ecological succession"? Give an example
process species replace each other in habitat in predictable sequence
An r-strategist will typically:Select all that apply.
produce smaller offspring, lots of offspring, little parental care
intrinsic growth rate
r is per capita growth @ instant of time= intrinsic rate of inc (max growth no limit by resource
Why can wet soils occur both near the equator, where rainfall is high, and at high latitudes, where rainfall is low?
rainfall high near equator; soil moisture reflect both rainfall & evaporation
Draw a graph showing the age structure of a population that is growing rapidly and a graph of a population that is stable.
rapid is triangle, stable is oval
island speices diversity reflect
rate new species arrive on island & rate species on island become extinct (eventually reach equilibrium)
How long did it take the human population to double from 1 billion to 2 billion? How about from 2 billion to 4 billion? What does this pattern say about the rate of population growth?
rate of human pop increased
Per capita growth rate
rate of pop growth per ind; avg # offspring/ ind r=(∆N/∆t)/N
fluxes
rates C flow from 1 reservoir 2 another
Secondary succession:
re establishment of communities following disturbance
The _____ of a species is usually the result of predation, competition, and other types of interaction between species.
realized niche
Survivorship curves: and types
record ∆s in survival probability over org's life span Type I: survive early yrs & steep decline in last part of life span ex) humans & large mammals Type II: constant death rate throughout lives ex) small mammals & birds Type III: high death @ early life stage, but those survive have slow decline ex) fish, frog, herbaceous plants
Phenology
recurring plant & animal life cycle stages & their timing & relationships w/ weather & climate; nature's calendar
What is one "low-tech" method currently available to actively remove CO2 from the air?
reforestation of previously cleared landscapes
habitat island
region surrounded by environments that can't support same species→ region that can support given species
Elevational range shifts
species adapted 2 high elevations climb mtns as temps rise, but eventually have nowhere to go
Invasive species:
species introduced 2 new area can b considered invasive is have negative impacts on native species
Draw and explain the curve representing the changing atmospheric levels of CO2 over the past 150 years.
steadily inc oscillations due to human activities
Demography
study of size, structure, distribution of pop over time
Following a disturbance, the process by which species replace each other over time is called:
succession
Evapotranspiration
sum of evaporation directly from soils & water bodies + amount transpired by plants
_____ describes the number of individuals in a species that survive from one life cycle stage to the next.
survivorship
competition can reduce
survivorship, growth, ∆ reproduction
Close interactions that have evolved over time between species are called
symbioses
T or f; At its earliest stages, a logistic growth curve closely resembles an exponential growth curve.
t
Whereas food chains show linear energy transfer between organisms, food webs depict more realistically what occurs in an ecosystem. truefalse
t
t or f: Overfishing predators of crown-of-thorns starfish is likely to result in an increase in crown-of-thorns starfish population sizes.
t
t or f: Some forms of M. tuberculosis are very difficult or even impossible to treat with antibiotics.
t
t or f: The evolution of biodiversity on the planet can be linked to patterns in the carbon cycle over time.
t
t or f: The intrinsic growth rate is the maximum per capita growth rate, most readily acheived when no environmental factors limit population increase.
t
t or f: The size of a population of frogs is significantly below the population size that the environment can support. This could be the result of frog parasites and/or predators
t
t or f; Niches are dynamic and are affected by interactions among species.
t
Which of these factors likely contributed to the accumulation of O2 within Earth's atmosphere?
the fact that there is a slight "de-coupling" between photosynthesis and respiration the evolution of cyanobacteria the fact that O2 is also cycled during the carbon cycle the fact that photosynthesis releases O2 as a product
Carrying capacity is:
the maximum number of individuals a habitat can support.
species richness
the number of different species in a community
life history
typical pattern of resource investment in each stage of a given species' lifetime; trade-offs among physiological function
Consider five human populations that differ demographically only in their age structures. The population that will grow the most in the next 30 years is the one with the greatest fraction of people in which age group(s):
the pre-reproductive age groups
Eutrophication describes:
the process in which added nutrient levels lead to the growth of algae and cyanobacteria populations, eventually causing oxygen availability to decline
Stratification
the process in which sedimentary rocks are arranged in layers. reflect temp diff b/w surface & deep water Turbulent river flow=well oxygen
ecosystem services
the processes by which life-supporting resources such as clean water, timber, fisheries, and agricultural crops are produced.
Species evenness
the relative proportion of different species in a given area
A group of scientists in Alaska notices that not only have atmospheric CO2 levels increased at their sampling site but so too have methane levels. What could account for this increase in methane levels?
the release of methane from thawed permafrost
The hypothesis that species diversity is greater at lower latitudes than higher latitudes because low-latitude habitats are older is a hypothesis that would be supported if speciation rates were:
the same at high and low latitudes. If speciation rates were equal at high and low latitudes, then the prediction is that regions that have existed for less time would have fewer species.
Keystone species can have significant influences over several populations in a community through:
their effects on key competitors in the communities. Keystone species help maintain population sizes of multiple species in the community by controlling the number of individuals of predator species in the community that would overexploit individuals of other populations in the community. In this way, keystone species help maintain higher levels of diversity when they are present in the community versus when they are absent from the community.
Why are the sides of tall mountains that face oncoming wind generally wetter than their opposite slopes?
this is rain shadow; air mass rise as move upward and over mtn ranges, cooling as ascend. as it cools it condenses and rains; opp side warm as descend, take in water vapor
Imagine that a lizard inhabits a desert where it has very few natural predators. During a year where resources are scarce, the lizard produces a smaller number of large eggs, rather than several small eggs. This is an example of a:
trade off. Egg number is related to the amount of resources devoted to reproduction. Even though she produces fewer eggs that are larger, this is a result of having to devote more resources to her own survival than to reproduction.
Energy flow through ecosystems can be depicted using a(n):
trophic pyramid
The fact that diverse types of Anolis lizards inhabit, or hunt in, different levels of the tree canopy is the result of the effects of resource partitioning. falsetrue
tru
t or f: As you hike from the base of a mountain to the top of the mountain, you would expect to see decreasing levels of biodiversity.
true Hiking from the base of the mountain to the top takes the hiker through different conditions. Temperatures are warmer at the base with cooler, harsher, and drier at the top, resulting in an altitudinal species gradient similar to the latitudinal gradient.
t or f: Symbiotic relationships are subject to natural selection.
true Relationships that benefit an organism increase their fitness. Because symbiotic interactions can have an effect on fitness, individuals with those associations can be selected for through natural selection.
t or f: If all other aspects of their lifestyles were equivalent, a vegetarian would have a smaller ecological footprint than someone who consumes a large amount of meat.
true Vegetarians consume food at lower trophic levels than an individual that eats meat. This means that vegetarians are utilizing a trophic level with more energy available. Individuals that eat meat are consuming at a trophic level where much of the energy in the primary consumer trophic level has been lost to metabolism and heat.
What is the coldest biome with the lowest biodiversity and a permanent layer of ice beneath the soil?
tundra
Explain energy flow in food webs and how this gives rise to biomass pyramids
while carbon and other elements are recycled in ecosystems, energy transfer is unidirectional. Because of wastes, work, and heat dissipation, only about 10% of the energy and biomass available at one trophic level is incorporated into the next level. A diagram that traces the flow of energy through communities, showing the amount of energy available at each level to feed the next. The pyramid shape results because biomass and the energy it represents generally decrease from one trophic level to the next.
how is heat transported to poles
wind & ocean currents
If a population triples in size in a year, what is the per capita growth rate?
∆n=3x-x=2x, and r=∆n/∆t/ n, so 2x/1/x=2
