LS7B Final Review
Two islands lie off the coast of Florida. One is larger and the other is closer to the mainland. What determines which one will have more species?
The closer island will initially receive more colonists than the farther one, but the larger island can eventually support more kinds of species.
metapopulation
a large population made up of smaller populations linked by migration
climax community
a mature assembly, a final stage in succession, in which there is little further change in species composition
mark-and-recapture
a method in which individuals are captured, marked in a way that doesn't affect their function or behavior, and then released. the percentage of marked individuals in a later exercise of capture enables ecologists to estimate population size.
resource partitioning
a pattern in which species whose niches overlap may diverge to minimize the overlap
disturbances
a severe physical impact on a habitat that has density-independent effects on populations of interacting species
Which factors contribute MOST to intraspecific competition? -mutualistic relationships -predation and parasitism -a species' fundamental niche and abiotic surroundings -a species' rate of reproduction and the carrying capacity of the environment -population size
a species' rate of reproduction and the carrying capacity of the environment
trophic level
an organism's typical place in a food web as a producer or consumer
A specie that is involved in a facultative mutualism with another: -can utilize a variety of different resources -can only interact with that particular species -should quickly develop adaptations in direct response to the other species -is reliant on the relationship for survival
can utilize a variety of different resources
symbiosis
close interaction between species that live together, often interdependently
When both participants in a species interaction develop adaptations in direct response to one another, in the long term this could progress into: -extinction of one species -intraspecific competition -coevolution -resource partitioning -competitive exclusion
coevolution
The sum total of the populations that live in a given area is called a(n): -community -habitat -ecosystem -interaction
community
intraspecific competition
competition between individuals of a single species
interspecific competition
competition between individuals of different species
Benefits associated with symbiotic relationships might include all of the following EXCEPT: -shelter -protection -nutrients -assistance in reproduction -competitive exclusion
competitive exclusion
obligate
describes a mutualism in which one or both sides cannot survive without the other
density-independent
describes factors such as severe drought that influence population size without regard for the density of the population
density-dependent
describes processes affecting populations that are influenced by the number of individual organisms, such as the use of resources or susceptibility to predation or parasitism
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 predation and resource availability. -realized;fundamental -realized;realized -fundamental;realized -fundamental;fundamental
fundamental;realized
greenhouse gas
gas that absorbs heat energy and then emits it in all directions (CO2, water vapor, methane)
parasites
organisms that live in close association with another species, consuming or gaining nutrition from their hosts' tissues, generally without killing them
K-strategists
organisms that produce few offspring but put in a lot of parental investment
r-strategists
organisms that produce large numbers of offspring without a lot of parental investment
keystone species
pivotal populations that affect other members of the community in ways that are disproportionate to their abundance or biomass
Which of the following is a good predictor of biodiversity in terrestrial ecosystems? -plant species in a community -predator species in a community -prey species in a community -pollinator species in a community
plant species in a community
Measuring its costs and benefits in terms of energy spent and/or gained, which interaction(s) involve(s) one individual gaining and one individual losing? -predation -commensalism -obligate mutualism -facultative mutalism -competition
predation
The _____ of a species is usually the result of predation, competition, and other types of interaction between species. -fundamental niche -realized niche -habitat -abiotic environment -resource partitioning
realized niche
range of species
reflects the range of climates a population can tolerate and determines how many other species the population encounters
per capita growth rate
the change in population size per unit of time divided by the number of individuals at the start r = (ΔN/N0)/Δt
niche
the combination of traits and habitat in which a species exist; determined by abiotic and biotic factors
pattern of decreasing biomass
transfer of energy and biomass is inefficient; 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
Liebig's Law of the Minimum
the principle that primary production is limited by the nutrient that is least available relative to its use by primary producers
ecological footprint
the quantification of individual human claims on global resources by adding up all the energy, food, materials, and services used and estimating how much land is required to provide those resources
competitive exclusion
the result of an antagonistic interaction in which one species is prevented from occupying a particular habitat or niche
Which of the following results from a mark-recapture study done on mice would reflect a large population size? -when taking the second sample, 200 individuals are caught and 20 are marked from the first sample -both of these scenarios would result in the same population estimate -when taking the second sample, 200 individuals are caught and 80 are marked from the first sample
when taking the second sample, 200 individuals are caught and 20 are marked from the first sample
theory of island biogeography
A theory that states that the number of species that can occupy a habitat island depends on two factors: the size of the island and the distance of the island from a source of colonists.
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; it is not immediately reintroduced back into the atmosphere. T/F?
T
If a population triples in size in a year, what is the per capita growth rate?
The per capita growth rate, r, equals (ΔN/Δt)/ N1. In this case, the change in time Δt is 1 year, so r = ΔN/N1. If the starting population is x, at triple the size it is 3x. Therefore, ΔN is 3x − x, or 2x, and r = 2x/x, or 2.
Why is the ratio of 18O:16O in glacial ice cores a good indicator of past temperature? -It tracks CO2 concentration very closely. -18O is isotopically unstable, even at cold temperatures. -The ratio decreases as temperature decreases. -This ratio causes a proportional change in CO2 concentration.
The ratio decreases as temperature decreases.
rain shadow
as wet air moves from the ocean up into the mountains, it cools, releasing its moisture as precipitation; moving past the mountains, air masses descend, warming as they go and taking up water vapor; for this reason, lands in the rain shadow of the mountains are arid
flux
the rate at which a substance, for example carbon, flows from one reservoir to another
succession
the replacement of species by other species over time; describes the community response to new habitats or disturbances
population density
the size of a population divided by its range; tells us how crowded or dispersed the individuals are that make up the population
What is the difference between global warming and the greenhouse effect?
Global warming is the measured increase in Earth's surface temperatures over the past 50 years. The greenhouse effect describes a process by which global warming can occur. The greenhouse effect is the result of the capacity of some molecules to absorb heat energy and then emit it in all directions. Without the greenhouse effect, Earth would not be habitable. However, in recent decades, increasing amounts of greenhouse gases in the atmosphere have resulted in global warming.
How did the eukaryotic cell originate?
Hypothesis 1: Eukaryotic cells evolved from an ancestral archaean and only later incorporated the proteobacterial cell that became a mitochondrian. Hypothesis 2: Eukaryotic cells evolved from a symbiosis between an archaean and a proteobacterium. The proteobacterium became a mitochondrian.
Predator/prey relationships are always linear, with one species affecting only one other in the community. T/F?
F
What is the difference between a community and an ecosystem?
A community is a set of organisms that live in a given place. A community together with the physical environment in which the organisms live constitutes an ecosystem.
trophic pyramid
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.
food web
A map of the interactions that connect consumer and producer organisms within the carbon cycle; the movement of carbon through an ecosystem.
If plate tectonic process from a chain of high mountains, would you expect atmospheric CO2 to increase or decrease?
All else being equal, increasing the elevation of mountains should increase rates of chemical weathering and erosion. As chemical weathering of continental rocks consumes CO2, atmospheric CO2 levels should decline.
Why should the capacity to shift flowering time influence the distribution of a species during the 21st century?
As ecosystems warm, plants able to open flowers earlier appear to have higher fitness, enabling them to maintain or increase their geographic ranges.
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 would not show strong seasonality.
Consider rising average global temperatures. As warming increases, rates of photosynthesis will also increase and remove excess CO2 from the atmosphere. T/F?
F
Why must a plant or animal make trade-offs among growth, reproduction, defenses, and other adaptive traits?
Every organism invests all available energy in the ways that are most useful in the current environment. Increase in one area means decrease in another. To increase investments in all these areas, more resources in terms of food or energy would have to be acquired.
What is the difference between competitive exclusion and resource partitioning?
In competitive exclusion, there is ongoing competition between two species for a particular resource, leading one to change its niche in the presence of the other. In resource partitioning, species evolve to use different resources, so there is no longer competition for that particular resource. Over time, competitive exclusion can lead to resource partitioning.
Recall that during the Paleozoic Era, atmospheric CO2 levels decreased. Why? -Earth's plate tectonics changed dramatically, and subduction increased. -Volcanism decreased during this period. -New, extensive mountain ranges formed and chemical weathering decreased. -Photosynthetic, woody plants first appeared during this period.
Photosynthetic, woody plants first appeared during this period.
This example of a trophic pyramid shows that the amount of energy passed on to each trophic level is far less than the total energy contained in the biomass in each trophic level. Why isn't the transfer of energy between trophic levels 100%? -Some of the energy consumed within each trophic level goes to supporting the organisms in that trophic level. -The energy consumed from one trophic level is converted to larger molecules of organismal biomass, and these take up less space in each trophic level. -All of the energy consumed is lost as heat or as waste products after digestion. -Only 10% of all the energy contained in the biomass of one trophic level will be eaten by the next trophic level.
Some of the energy consumed within each trophic level goes to supporting the organisms in that trophic level.
Niches are dynamic, and are affected by interactions among species. T/F?
T
Symbiotic relationships are subject to natural selection. T/F?
T
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. T/F?
T
The interplay of pathogens and antibiotics again brings up the problem of the Red Queen. How does the Red Queen hypothesis apply to these kinds of interaction?
The Red Queen hypothesis suggests that organisms need to keep evolving (running) just to stay in the same ecological niche (place). As new antibiotics are developed, pathogens like malaria frequently evolve resistance, so researchers must continually strive to develop new medicines as natural selection erodes the effectiveness of the old.
A gardener treats his plants with pesticides, killing any aphids. Once the aphids die, what likely happens to the mutualistic bacteria inhabiting their digestive tracts? -The bacteria would contribute to the decomposition of dead aphids. -The bacteria would likely die without their mutualistic aphids, as this is an example of a facultative relationship. -The bacteria would likely die without their mutualistic aphids, as this is an example of an obligate relationship. -The bacteria would migrate outside of the digestive tract, and survive on the leaves of garden plants.
The bacteria would likely die without their mutualistic aphids, as this is an example of an obligate relationship.
mutualism
an interaction between two or more species that benefits all (+/+)
facilitation
a beneficial indirect interaction between organisms that are independently interacting directly with a third, as when two different organisms attack another organism, and the attack of each is aided as a result
ecosystem
a community of organisms and the physical environment it occupies
Recall that photosynthetic rates remain relatively constant in regions near the equator. Imagine that tropical environments persisted throughout Earth's northern and southern hemispheres (i.e., Earth's entire climate mirrored 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 sinusoidal curve sloping downward (atmospheric CO2 levels would fluctuate seasonally, but would have decreased over time) -a straight line sloping downward (atmospheric CO2 levels would not seasonally oscillate, but would have decreased over time) -a straight line without a slope (atmospheric CO2 levels would have remained constant over time) -a sinusoidal curve sloping upward (atmospheric CO2 levels would fluctuate seasonally, but would increase over time) -a straight line sloping upward (atmospheric CO2 levels would not seasonally oscillate, but would have increased over time)
a straight line sloping upward (atmospheric CO2 levels would not seasonally oscillate, but would have increased over time)
reservoir
a supply or source of a substance. reservoirs of carbon, for example, include organisms, the atmosphere, soil, the oceans, and sedimentary rocks
population
all the individuals of a given species that live and reproduce in a particular place; one of several interbreeding groups of organisms of the same species living in the same geographical area
ocean acidification
an increase in the abundance of carbon dioxide in the oceans that causes the pH of seawater to go down
predation
an interaction between organisms in which one (the predator) consumes the other (the prey)
commensalism
an interaction between species in which one partner benefits with no apparent effect on the other (+/0)
biodiversity
biological diversity; the aggregate number of species, or, more broadly, also the diversity of genetic sequences, cell types, metabolism, life history, phylogenetic groups, communities, and ecosystems
what affects population size
birth, death, immigration, and emigration
The CO2 level is _____ during winter in the northern hemisphere compared to levels in the summer. -lower -higher -the same
higher
A researcher is comparing the species diversity of two islands. Both islands are roughly equal in size. However, one island is much closer to the mainland. She determines that the S value for the island closer to the mainland is _____ the S value for the island located farther from the mainland. In addition, she finds that the closer island's extinction rate is _____ the extinction rate on the farther island.
higher than; the same as
facultative
in mutualisms, describes one in which one or both sides can survive without the other
Measuring the isotopic composition of atmospheric CO2 shows that the burning of fossil fuels has led to _____ CO2 levels over the last 200 years. -decreasing -increasing
increasing
competition
is an interaction in which the use of .a mutually needed resource by one individual or group of individuals lowers the availability of the resource for another individual or group
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: -exponential growth because only a few individuals will have offspring. -logistic growth because the colonizing population will reach carrying capacity within the first two years. -exponential growth because the colonizing population size will remain below the carrying capacity for the first two years. -logistic growth because they will reach maximum population size immediately after colonization.
logistic growth because the colonizing population will reach carrying capacity within the first two years.
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. -short-term carbon; rapid carbon -long-term carbon; intermediate carbon -long-term carbon; short-term carbon -short-term carbon; long-term carbon
long-term carbon; short-term carbon
Overlap of niches can be minimized through: -an increase in the similarity of species occupying an area -increased population growth -species evolving similar adaptations over time -reduction in the size of the fundamental niche -resource partitioning
resource partitioning
Which of the following is expected to reduce competition among individuals? -a decrease in the carrying capacity of an environment -destruction of habitat space -resource partitioning -the disappearance of a predator from an area -a shortened mating season
resource partitioning
Measuring its costs and benefits in terms of energy spent and/or gained, mutualism: -results in a gain for one individual and neither a gain nor a loss for the other -is a lose-lose interaction -results in gain for both individuals -none of the answer options is correct -results in a gain for one individual and a loss for the other
results in gain for both individuals
Which is faster? -primary succession -secondary succession
secondary succession (life and soil are already present)
endemic species
species found in one place in the world and nowhere else
realized niche
the actual range of habitats occupied by a species
herbivory
the consumption of plant parts
biome
the distinctive and stable assemblage of species found over a broad region of Earth; terrestrial biomes are each recognized by their distinctive vegetation
range
the extent of the geographic area over which the populations of a species are distributed
fundamental niche
the full range of climate conditions and food resources that permit the individuals in a species to live
latitudinal diversity gradient
the increase in species diversity from the poles to the equator
food chain
the linear transfer of carbon from one organism to another
anthropocene period
the modern era, so named to reflect the dominant impact of humans on Earth
The expanding base of a population pyramid over time indicates which of the following? -the average age of the population is increasing -the number of older people in the population is increasing -the number of people of reproductive age in the population is increasing -the number of younger individuals in the population is increasing
the number of younger individuals in the population is increasing
phylogenetic niche conservatism
the observed similarity in closely related species of some aspect of their niches, indicating its presence in their common ancestor
exponential growth
the pattern of population increase that results when r(the per capita growth rate) is constant through time
intrinsic growth rate
the per capita growth rate; the maximum rate of growth when no environmental factors limit population increase
Coriolis effect
the phenomenon in which, because of Earth's counterclockwise rotation about its axis, winds and oceanic currents in the Northern Hemisphere deflect to the right, and those in the Southern Hemisphere deflect to the left
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 oldest age group -the middle of the reproductive age groups -the late-reproductive and post-reproductive age groups -the middle of the age structure -the pre-reproductive age groups
the pre-reproductive age groups
