LS 7B (Summer) Week 6 Launchpad 3e
Refer to VS Map: Succession Ecology—Stages of Succession Tour. If the population size (N) is 1,000 individuals and the range is 10 km, what is the population density?
100 individuals/km
Most climate models predict that during the 21st century mean global temperature will increase by:
2-5 °C.
How many "cells" of circulating air are found around the Earth?
6
What is the approximate size of the human population today?
7 billion people
Which of these factors likely contributed to the accumulation of O2 within Earth's atmosphere?
All of these choices are correct.
Which of the statements about coral bleaching is true?
All of these choices are true.
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.
Refer to Animation: Dead Zones. 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.
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.
Refer to VS Map: Succession Ecology—Stages of Succession Tour. Match the scenario (I, II, or III) with the population growth shown at the numbered points (1, 2, or 3) in the graph. I) A species has used up all the resources and the habitat cannot sustain additional population growth. II) Resources are abundant and there is adequate space for the species population. III) Species experiences exponential growth and is growing at the maximum rate the habitat can sustain.
I) - 3; II) - 1; III) - 2
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.
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.
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.
Which of the statements explains how an oxygen-rich atmosphere became possible on Earth?
Rates of oxygen consumption are lower than rates of photosynthesis.
If Earth had no oceans, would temperatures at the equator be hotter or colder than they are now?
Temperatures would be hotter.
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.
Refer to Animation: Greenhouse Effect. Which of the answer choices is false?
The greenhouse gases in the atmosphere have all come from human activity.
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).
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?
There are fewer species in temperate regions because the number of trees per hectare is lower than in tropical rainforests.
Which factors contribute most to intraspecific competition?
a species' rate of reproduction and the carrying capacity of the environment
Refer to Animation: Dead Zones. 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
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
Refer to Animation: Dead Zones. Which of the answer choices is directly responsible for depleting the supply of oxygen in bottom waters?
bacterial growth
A species that is involved in a facultative mutualism with another:
can utilize different resources outside of the mutualism.
Refer to Animation: Greenhouse Effect. 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?
carbon dioxide produced as a result of aerobic cellular respiration in living organisms
Autotrophs remove _____ from the air and fix this into tissues providing _____ for secondary consumers.
carbon dioxide; energy
In addition to burning fossil fuels, humans return CO2 to the atmosphere faster than it can be removed by:
clearing forests for agriculture.
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.
The high specific heat of water means that land masses near the equator are:
cooler than predicted because of all the heat carried by ocean waters from low to high latitudes.
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?
decomposers
In terrestrial ecosystems, nitrogen is returned to the atmosphere by:
denitrifying bacteria.
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.
Increased phosphate levels in the Everglades has led to:
displacement of native plants by phosphate-loving introduced plants.
When two species compete for resources the fitness of:
division of limited resources by species to help avoid competition in an ecological niche
A community of organisms and the physical environment it occupies are known together as a(n):
ecosystem.
Refer to Animation: Dead Zones. Which of the answer choices is responsible for the increased growth of algae in the dead zones?
elevated phosphorous and nitrogen in the water
In marine ecosystems phosphorus is added to the ecosystem primarily from:
erosion of rocks on land
Nitrogen runoff leads to large increases in the populations of algae and cyanobacteria in lakes and oceans in a process known as:
eutrophication.
If all of the tertiary consumers were removed from an environment, the associated food web, and thus the carbon cycle, would collapse.
false
Predator/prey relationships are always linear, with one species affecting only one other in the community.
false
Refer to the figures shown. Most of Earth's primary production comes from tropical rainforests.
false
The sequence of types of species that colonize a recently disturbed area through succession is unpredictable.
false
A _____ depicts the flow of carbon through an ecosystem, whereas a _____ depicts the transfer of energy.
food web; trophic pyramid
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
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
Given models of population growth, which model would be the best to use for determining estimated sustainable yield?
logistic
Refer to VS Map: Succession Ecology—Stages of Succession Tour. What type of population growth is shown in the graph?
logistic
Which regions in freshwater or marine biomes would you expect to have the highest productivity?
near the surface where sunlight penetrates
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.
Refer to Animation: Greenhouse Effect. Which of the answer choices is not an example of a greenhouse gas?
oxygen
Which of these is a good predictor of biodiversity in terrestrial ecosystems?
plant species in a community
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.
Measuring its costs and benefits in terms of energy spent and/or gained, which interaction definitely involves one individual gaining and one individual losing?
predation
Organisms that take up inorganic nutrients and convert them to organic molecules such as carbohydrates and proteins are called:
primary producers.
The broadest level in a trophic pyramid is primarily composed of:
primary producers.
The _____ of a species is usually the result of predation, competition, and other types of interaction between species.
realized niche
What is one "low-tech" method currently available to actively remove CO2 from the air?
reforestation of previously cleared landscapes
Overlap of niches can be minimized through:
resource partitioning
Which of the answer choices is expected to reduce competition among individuals of different species?
resource partitioning
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.
Following a disturbance, the process by which species replace each other over time is called:
succession.
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.
Keystone species can have significant influences over several populations in a community through:
their effects on key competitors in the communities.
Energy flow through ecosystems can be depicted using a(n):
trophic pyramid.
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
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
Niches are dynamic and are affected by interactions among species.
true
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.
The sum total of populations of different species that live in a given area is called a(n):
community.
Which of the answer choices is a type of interaction in which both parties are harmed?
competition
Benefits associated with symbiotic relationships might include all of these except:
competitive exclusion.
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
Refer to Animation: Dead Zones. 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.
Genetic variation within species is important to conservation because:
genetic variation provides a means by which natural selection can "act" when the environment changes.
Refer to VS Map: Succession Ecology—Stages of Succession Tour. Which scenario might slow population growth? Select all that apply.
growing population size reduces the amount of space available as a proper habitat competition within species for the same resources
If phosphorous concentrations were to suddenly increase in a marine ecosystem, which of the choices would likely occur?
increased primary productivity
Refer to Animation: Greenhouse Effect. Which of the answer choices is reflected back to the Earth's surface by greenhouse gases?
infrared radiation
An invasive species:
is any non-native species that becomes established in a new ecosystem.
A species that has a disproportionately large effect on a community is called a(n) _____ species.
keystone
Warm air is _____ dense than cold air, and warm air holds _____ moisture than cold air.
less; more
Which of these organisms can incorporate atmospheric carbon directly into C6H12O6, thereby playing a major role in a food web?
primary producers
Close interactions that have evolved over time between species are called:
symbioses.
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.
Refer to VS Map: Succession Ecology—Stages of Succession Tour. Population range is:
the area over which a population is spread.
Refer to VS Map: Succession Ecology—Stages of Succession Tour. Carrying capacity is:
the maximum number of individuals a habitat can support.
Eutrophication describes:
the process in which added nutrient levels lead to the growth of algae and cyanobacteria populations, eventually causing oxygen availability to decline.
Overfishing predators of crown-of-thorns starfish is likely to result in an increase in crown-of-thorns starfish population sizes.
true
Some forms of M. tuberculosis are very difficult or even impossible to treat with antibiotics.
true
Symbiotic relationships are subject to natural selection.
true
The evolution of biodiversity on the planet can be linked to patterns in the carbon cycle over time.
true
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.
true
Whereas food chains show linear energy transfer between organisms, food webs depict more realistically what occurs in an ecosystem.
true
What is the coldest biome with the lowest biodiversity and a permanent layer of ice beneath the soil?
tundra
