GES Quiz 8

In what terrestrial environment would you expect to find the highest annual net primary productivity? a) tropical rainforest b) subtropical high pressure belts c) temperate midlatitude locations d) polar latitudes, where the days are longest during the summer growing season e) midlatitude grasslands

a

In which biome are we most likely to find vegetation that is adapted for frequent occurrence of fire? a) Mediterranean chaparral/sclerophyll forest b) midlatitude broadleaft deciduous forest c) subtropical desert d) tropical rainforest e) taiga/boreal forest

a

Organisms that are capable of using CO2 as their sole source of carbon are a) Primary producers b) Decomposers c) Primary consumers d) Secondary consumers

a

Most desert environments are basically devoid of vegetation. a) True b) False

b

N 2 makes up almost 80% of our atmosphere by weight. Nitrogen is an essential plant nutrient. a) Because N is so easily available, it is never a limiting nutrient for plant growth b) N2 is a form of nitrogen that cannot be assimilated by most plants; only a few types of organisms can "fix" nitrogen chemically in a form that is available for uptake as a nutrient c) N2 is a greenhouse gas d) combustion of fossil fuels has added huge amounts of N2 to the atmosphere

b

Which of the following biomes would you be most likely to find in Africa at a location between the equatorial zone and the great subtropical deserts? a) rainforest b) savanna c) Mediterranean shrubland/sclerophyll forest d) taiga e) mixed broadleaf deciduous forest

b

Which statement about the global carbon cycle is not true? a) Annual CO2 inputs to the atmosphere are now larger than amounts being removed from the atmosphere b) Net CO2 contributions to the atmosphere have been increasing throughout most of earth history c) A large fraction of the CO2 added to the atmosphere currently goes into solution in the world's oceans d) Burning of fossil fuels and deforestation and clearing of vegetation account for a significant input of CO2 to the atmosphere e) Photosynthesis takes CO2 out of the atmosphere and respiration puts CO2 into the atmosphere

b

Some biomes are dominated by deciduous trees and some are dominated by evergreen trees. Which of the following statement about the comparison between these two types of trees is false? (You can look this up online, for example by looking at the Wikipedia article on deciduous trees.) a) deciduous trees are found only in environments with a cold winter season b) deciduous trees need to regrow their leaves with each new growing season and therefore need to expend resources that evergreen trees to not need to expend c) evergreens do not drop their leaves and therefore suffer greater water loss in winter and greater stress from insects feeding on their leaves than deciduous trees d) deciduous trees can be found both in temperate climates with alternating winter and summer seasons and in tropical wet-dry climates as part of the tropical and subtropical dry broadleaf forest biomes

a

The spatial distribution of terrestrial biomes on the earth's surface a) Is strongly related to the spatial distribution of global climate types b) Has a controlling influence on global climate patterns c) Is mostly controlled by factors other than climate d) changes rapidly in response to short-term changes in weather patterns

a

What factor is MOST responsible for the "dead zone" that develops in the Gulf of Mexico every year? (Note: Chesapeake Bay suffers from the same problem.) a) excessive discharge of nutrients (especially nitrates) in runoff from agricultural land in the Mississippi River basin b) toxic contamination from industrial chemicals c) this is a natural phenomenon that cannot be attributed to human activity d) effluent from sewage treatment plants in Texas and Louisiana

a

What is the difference between biomass and net primary productivity? a) biomass is the amount of "standing crop" of living organic matter per unit surface area in an ecosystem, whereas net primary productivity is the rate at which living organic matter is being produced after accounting for respiration loss b) biomass is the rate at which organic matter is being created by photosynthesis in an ecosystem, whereas net primary productivity is the amount or mass of "standing crop" per unit surface area at a particular moment c) biomass is the remaining amount of organic matter per unit surface area whereas net primary productivity is the rate at which organic matter is broken down by respiration d) biomass and net primary productivity are interchangeable terms that both mean the same thing: the rate at which new organic matter is being produced by photosynthesis in an ecosystem

a

Where would you expect to find the lowest biodiversity? a) Arctic tundra b) Tropical rainforest c) Midlatitude grassland d) Midlatitude forest

a

Which of the following is true? a) In some ecosystems where fire occurs frequently, some plants may be adapted to take advantage of fire as a means of dispersing their seeds b) disturbance occurs very rarely in most ecosystems and disturbances like fire, floods, and wind storms typically lead to collapse of the ecosystem c) human activity typically leads to increased biodiversity in ecosystems where people are present d) the more nutrient we add to an ecosystem, the greater its biodiversity will be all of the above

a

As you climb from the base to the top of a high mountain in a tropical region, a) there is greater seasonal variation in the amount of solar radiation received than there is at sea level b) you may encounter a sequence of biotic communities similar to what you would find if you traveled from the equator to the polar latitudes on the earth's surface c) the vegetation becomes more and more characteristic of what you might find in a desert because the air gets thinner d) vegetation is more luxuriant at higher altitudes because there is more CO2 in the atmosphere than there is at sea level

b

Biodiversity is a) a measure of the total number of individual organisms in an ecosystem b) a measure of the total number of different species per unit area of an ecosystem c) a measure of the total number of different trophic levels in an ecosystem d) a measure of the efficiency of energy conversion by primary producers in an ecosystem

b

The rate of carbon fixation in living tissues per unit time after accounting for the amount used to meet the plant's own metabolic needs is a) gross productivity b) net productivity c) carbon sequestration d) primary consumption

b

The savanna biome is a grassland environment similar to midlatitude prairie; it has no trees. a) True b) False

b

The taiga environment is a grassland environment similar to midlatitude prairie; it has no trees. a) True b) False

b

The temperate rainforest biome is found only in association with which climate type? a) humid subtropical (Cfa) b) marine west coast (Cfb) c) humid continental (Dfa) d) monsoon (Am) e) subarctic (Dwd)

b

Arctic tundra is a unique biome type. All but one of the following describe conditions associated with the tundra environment. Which answer does not fit with the others? a) very short growing season b) poor drainage owing to underlying permafrost blocking the downward seepage of moisture during the growing season c) dominated by coniferous trees and shrubs d) characterized by low, fragile, and very slow-growing herbaceous vegetation e) relatively low diversity

c

What is the definition of the term "limiting factor" from the point of view of an ecologist? a) it is the maximum rate of primary production that is possible in any given ecosystem b) it is the environmental factor that causes massive loss of life and the sudden disappearance of a particular species or population from an ecosystem c) it is the factor (for example light, nutrient concentration, oxygen, water) that is necessary to sustain growth of a population and that is also in shortest supply relative to the needs of the organism d) it is a physical barrier that limits the ability of an organism to spread to a new habitat, such as a mountain range or an ocean

c

What is the difference between habitat and niche? a) Habitat is the environment where an organism lives and niche is the community of organisms living in that environment b) Habitat is the environment where an organism lives and niche is the home it makes for itself, e.g. a nest or burrow c) Habitat is the environment where an organism lives and niche describes the way it lives and role it plays in terms of trophic level, feeding habit, how it moves around, migration, reproduction, etc. d) The two terms are synonyms and can be used interchangeably

c

What is the process that converts nitrate into nitrogen gas? a) nitrification b) ammonification c) denitrification d) nitrogen uptake by plants

c

Which of the following is an adaptive advantage related to vegetation characteristics of dominant vegetation in boreal forests? a) broad leaves that drop off at the end of the growing season and replaced by new leaves at the beginning of the growing season b) deep roots that can reach the water table during extremely dry periods c) needle leaves that stay on the tree and that can begin photosynthesis at the beginning of a short growing season without having to wait until they are fully grown d) tall growth form with multiple canopy levels supporting abundant lianas and epiphytes e) relatively short growth form with waxy leaf coatings and ability to respond quickly after fire

c

Which of the following statements about ecological succession is FALSE? (choose just one) a) succession is a term used to describe the series of changes in composition of a biological community over time after an initial disturbance b) the pioneer species that come in first after disturbance generally are able to disperse rapidly, grow quickly, and are tolerant of stressful environmental conditions c) all ecosystems will inevitably evolve toward a stable "climax community" d) the modern view involves the concept of "patch dynamics" and sees ecosystems as a mosaic of different habitat types in different stages of succession.

c

Which term describes the concept that populations have ranges that are optimal, that are associated with physiological stress, and that are incompatible with survival? a) reslieince b) biodiversity c) environmental tolerance d) amensalism

c

A species that evolves within a limited geographic range and is native nowhere else would be described as a) cosmopolitan b) pioneer c) tertiary d) endemic

d

Conifer or needleleaf evergreen trees can be found a) in the taiga biome b) in the temperate rainforest biome c) in temperate subtropical environments d) all of the above

d

In which of the following biomes of North America has the natural vegetation assemblage been replaced to the greatest extent as a result of human activity? a) boreal forest b) mixed broadleaf deciduous forest c) savanna d) midlatitude grassland e) hot desert

d

The capacity of an ecosystem to recover from disturbance, or to absorb the effects of disturbance without collapse, is known as _______. a) climax b) immunity c) inertia d) resilience e) stability

d

What is the typical efficiency of conversion of energy stored in biomass at one trophic level to energy stored in biomass at the next trophic level? a) 75% b) 0.1% c) 35% d) 10%

d

Which of the following statements about biodiversity is FALSE? a) the terrestrial ecosystems with the highest biodiversity are tropical rainforests b) biodiversity generally reflects or results from genetic diversity in an ecosystem, which leads to speciation in response to environmental change c) greater biodiversity in an ecosystem is associated with better ability to recover from or avoid devastation by diseases and parasites d) modern agricultural ecosystems are among the most diverse terrestrial ecosystems on the earth's surface

d

Why do surface waters in the middle of the ocean have such low primary productivity? a) temperature is a limiting factor b) light is a limiting factor c) salinity limits the rate of primary production in the ocean d) lack of availability of nutrients limits the rate of primary production e) all of the above

d

As you move west from the Mississippi River to the Rocky Mountains at a latitude that is about the same as that of Baltimore, what biomes are dominant under natural conditions? a) temperate rain forest b) warm subtropical desert c) needleleaf forest d) Mediterranean shrubland e) midlatitude grassland or steppe

e

How might climate change affect plant communities? a) increased geographic range of insect pests and diseases could pose threats to mid- and high-latitude forests b) rapid change in the geographic range of plants might lead to local extinctions and loss of biodiversity if populations cannot disperse fast enough to keep up with the change c) as life zones that vary with altitude in tropical montane ecosystems are forced to shift upward with rising temperatures, populations living at the highest altitudes will have nowhere to go and will die out d) changes in the length of the growing season could affect plant growth e) all of the above are either already observed or potential changes associated with climate change

e

What is the most important role of bacteria and fungi in natural ecosystems that was discussed in class? a) they serve primarily as disease vectors that cause infections, and they control populations of primary and secondary consumers in order to keep the system in balance b) they secrete organic compounds that assist primary consumers in neutralizing toxic chemicals in their diet c) they recycle organic waste material (detritus) and break it down to forms that are available for use by plants as nutrients d) a limited number of species have the ability to "fix" N2 from the atmosphere and to create forms that can be taken up as nutrients by plants e) both c. and d. are among the most important functions

e

What process is described by the chemical equation shown below? C 6H 12O 6 + 6O 2 ⇒ 6 CO 2 + 6H 2O + energy a) photosynthesis b) adsorption c) secondary consumption d) perambulation e) respiration

e

Which of the following is characteristic of food webs? a) primary producers b) two or three levels of consumers c) decomposers d) a trophic "pyramid" with much more biomass at the base and relatively small amounts of biomass at the top e) all of the above

e

Temperate deciduous forest can be found associated with which of the following climate types? a) Cfa b) Dfa c) BWk d) Cfb e) Dwd f) Answers 1, 2 and 4 above all represent climate regions where temperate deciduous forest can be found.

f

Which of the following factors does NOT affect the geographic range of populations of plants or animals? a) environmental tolerance, e.g. temperature, moisture, salinity, light availability b) dispersal and migration patterns c) geographic barriers d) reproductive strategies e) feeding strategies f) all of the above factors can influence the geographic range

f