Bio practice exams (4th exam) ECOLOGY
Which of the following is not true of terrestrial biomes? A) Annual temperature alone predicts which terrestrial biome will be found in an area. B) Changes in temperature over large areas of Earth are predicted to result in shifts of terrestrial biomes from one region to another. C) Terrestrial biomes are major ecosystems defined by their characteristic plant communities and abiotic factors.
A) Annual temperature alone predicts which terrestrial biome will be found in an area.
A bird species, the white-browed warbler, breeds in Colorado. Three quarters of the population migrates southwest to overwinter in Mexico, whereas one quarter migrate south to overwinter in Texas. The white-browed warbler migrates at night. Which of the following experimental designs is sufficient to determine if this difference in migratory behavior within the population has a genetic basis? In all experiments, to determine the attempted migration direction individual birds were placed in an experimental chamber open to the night sky. A) Capture adult birds from Mexico and Texas. Bring them back to Colorado, keeping Mexico and Texas birds separate in captivity. At breeding time, take their eggs and hand raise the chicks, keeping them away from their parents and each other. Observe which direction these offspring attempt to migrate. B) Tag adult birds (i.e. place a small metal ring around the leg to uniquely identify the individual) in Mexico and Texas so as not to interfere with their return migration to Colorado. When they return to Colorado, observe these tagged individuals raising their offspring in the wild so as not to interfere with the growth of the chicks. Capture these offspring before they migrate and observe which direction they attempt to migrate. C) Capture adult birds in Mexico and Texas. Bring them back to Colorado, keeping Mexico and Texas birds separate in captivity but allowing the adults to raise their offspring to minimize human interference. Observe which direction these offspring attempt to migrate. D) Capture adult birds in Mexico and Texas and bring them back to Colorado. During their migration time, observe which direction these individuals attempt to migrate.
A) Capture adult birds from Mexico and Texas. Bring them back to Colorado, keeping Mexico and Texas birds separate in captivity. At breeding time, take their eggs and hand raise the chicks, keeping them away from their parents and each other. Observe which direction these offspring attempt to migrate.
Epiphytic orchids are plants that live on the branches or trunks of trees. The trees supply the orchids with space, and the orchids (which are autotrophs) do not appear to affect the tree. What type of relationship is this? A) Commensalism B) Competition C) Mutualism D) Herbivory
A) Commensalism
Which of the following is true? A) Energy flows, nutrients cycle B) Energy cycles, nutrients cycle C) Energy flows, nutrients flow D) Energy cycles, nutrients flow
A) Energy flows, nutrients cycle
Which of the following describes a successional process in which one organism makes the environment more suitable for another organism? A) Facilitation B) Primary environment creation C) Secondary environment creation D) Mutualism E) Commensalism
A) Facilitation
As a result of World War I and the influenza epidemic of 1918, approximately 50 million people (3% of world's population) died in 1918-1919. The birth rate for 1918-1919 ranged from 1.6-1.9%. What conclusion can you reasonably make? A) Human population growth was negative for the year 1918-1919. B) Human population remained approximately constant during 1918-1919. C) Human population continued to grow, but much more slowly, during 1918-1919 D) The rate of human population growth was unaffected during 1918-1919.
A) Human population growth was negative for the year 1918-1919.
Which of the following statements is true? A) Most populations have the potential for unlimited growth but not a single population has ever been observed to sustain it for long B) In exponential growth, the per capita rate of increase accelerates with time C) Populations with exponential growth are better competitors D) Populations can never have unlimited growth under any circumstances E) All populations have the potential for unlimited growth but only some populations can sustain it indefinitely
A) Most populations have the potential for unlimited growth but not a single population has ever been observed to sustain it for long
Which of the following is the correct association of concepts? A) S-shaped, limited, density dependent B) Exponential, unlimited, density dependent C) Exponential, limited, density independent D) J-shaped, unlimited, density dependent E) B and D are both correct
A) S-shaped, limited, density dependent
Which of the options listed below is a biotic factor within an ecosystem? A) The predators that consume other animals B) The rate of flow of water in a river C) The amount of oxygen in the air D) The climate in a given region
A) The predators that consume other animals
In many bird species, day length stimulates the production of hormones, which determines when breeding occurs. This statement emphasizes ______________ cause. A) a proximate cause B) an ultimate cause
A) a proximate cause
You are most likely to observe secondary succession when you visit A) a tropical rain forest B) a parking lot in the city C) a recently retreated glacier D) an abandoned highway E) a recent volcanic lava flow
A) a tropical rain forest Especially in tree gaps in the forest. The other answers are examples of primary succession since there is no soil
The fundamental law of population dynamics states that A) change in population size is the net result of births, deaths, emigration, and immigration B) populations are fundamentally dynamic C) populations are neither conserved nor destroyed; their energy is in balance and simply changes form D) populations are conserved when they are below the carrying capacity but destroyed when they are above the carrying capacity E) population growth depends fundamentally on sunlight
A) change in population size is the net result of births, deaths, emigration, and immigration
The intermediate disturbance hypothesis is the idea that A) communities with intermediate levels of disturbance tend to have more species than communities with high or low levels of disturbance B) communities with intermediate levels of disturbance tend to have fewer species than communities with high or low levels of disturbance C) communities need disturbance to maintain intermediate numbers of trophic links D) secondary succession occurs after an intermediate disturbance, whereas primary succession occurs after a severe disturbance E) None of the above represent the intermediate disturbance hypothesis
A) communities with intermediate levels of disturbance tend to have more species than communities with high or low levels of disturbance
Which of the following combinations of factors help best to explain the distribution of species? A) dispersal, interactions with other species, and abiotic factors B) energy flow and biotic factors C) carrying capacity and the length of food chains D) trophic structure and abiotic factors E) abiotic factors and interactions with other species
A) dispersal, interactions with other species, and abiotic factors
q 66 In the diagram above, A is a plant and the arrows indicate the flow of nutrients in the ecosystem. Fill in the blanks. Most likely B is a __________, C is a __________, and D is a ___________. A) herbivore; detritus reservoir; microorganism B) primary consumer; primary consumer; competitor C) secondary consumer; microorganism, fungi D) primary consumer; primary consumer; predator E) primary consumer; secondary consumer; top predator
A) herbivore; detritus reservoir; microorganism
You are concerned about the fate of the red-nosed gecko on Tropical Heaven Island National Park. To find out about its population dynamics you tag and monitor 100 random females and 100 random males for a year. Of the females, you find that 32 geckos died and that 35 geckos gave birth to 4 surviving offspring each. Of the males you find that 34 geckos died. Assuming a stable sex ratio with equal numbers of males and females, the population is likely A) increasing B) stable C) declining
A) increasing On exams, make the calculation and determine whether the change is 0, <0 or >0 and choose no change, increasing or decreasings respectively
At birth, baby kangaroos climb to their mother's pouch and begin to nurse. This behavior is A) innate B) learned C) migration D) ultimate E) proximate
A) innate
In limited population growth, which of these is not a consequence of a high population density? A) reproduction per individual increases B) mortality rate per individual increases C) accumulation of wastes Incorrect Response D) intraspecific competition increases
A) reproduction per individual increases
Consider a food chain that consists of three trophic levels: grass, sheep and foxes. Approximately what percentage of the energy fixed by primary producers does the fox receive? A) 0.1% B) 1% C) 10% D) 20% E) 90%
B) 1%
Trophic efficiencies, the percentage of production transferred from one trophic level to the next, usually range between: A) 2-8% B) 5-20% C) 15-30% D) 25-40% E) 35-50%
B) 5-20%
Which of the following is a behavioral pattern resulting from an ultimate cause? A) A male bluebird (Sialia cyansis) attacks a blue ball because many times in the past blue balls have been thrown at it, and it has learned that blue balls are dangerous. B) A male bluebird (Sialia cyansis) attacks a blue ball because he mistakenly believes that it is another male trying to steal his nesting territory. C) A male bluebird (Sialia cyansis) attacks a blue ball because hormonal changes in spring increase its aggression
B) A male bluebird (Sialia cyansis) attacks a blue ball because he mistakenly believes that it is another male trying to steal his nesting territory.
Which of the following is not true of terrestrial biomes? A) Terrestrial biomes are major ecosystems defined by their characteristic plant communities and abiotic factors B) Annual temperature broadly predicts which terrestrial biome will be found in an area C) Changes in temperature over large areas of Earth are predicted to result in shifts of terrestrial biomes from one region to another D) None of the above, they are all true
B) Annual temperature broadly predicts which terrestrial biome will be found in an area Annual temperature together with annual precipitation broadly predicts biomes. Annual temperature alone is not enough
What are population dynamics? A) Proportion of individuals at each possible age B) Changes in populations through time C) The growth rate of the population D) The balance of births and deaths in a population E) Factors influencing the number of births in a population
B) Changes in populations through time
You have an hypothesis that the presence of a predator is responsible for explaining the distribution of an intertidal snail species. Which of the following would confirm your hypothesis? A) Make a large number of replicate surveys in the intertidal habitat at random sites along the coast. Survey each site for the presence of predators and the presence of snails. If the presence of the predators is correlated with the absence of snails this demonstrates that predators are responsible B) Conduct a removal experiment of predators from intertidal habitat at a smaller but random set of sites along the coast. If removal of the predators results in an increase of snail abundance compared to random unmanipulated control plots, this demonstrates that predators are responsible C) Either one of A or B would be sufficient to confirm the hypothesis
B) Conduct a removal experiment of predators from intertidal habitat at a smaller but random set of sites along the coast. If removal of the predators results in an increase of snail abundance compared to random unmanipulated control plots, this demonstrates that predators are responsible
True or false? An organism's environment is only defined as all of the abiotic factors such as temperature, light, nutrients, and shelter, that determine where it lives. A) True B) False
B) False
True or false? If the lowest trophic level of an ecosystem contains 15,000 grams of biomass per square meter, it is reasonable to expect the tertiary consumer level to contain about 150 grams of biomass per square meter. A) True B) False
B) False
As we discussed, the distribution and abundance of red kangaroos in Australia is negatively correlated with rainfall. That is, kangaroos are more abundant where there is less rain and absent where rain is plentiful. What can we conclude from this pattern? A) Kangaroos need water to survive B) Nothing, both rainfall and interactions (e.g. competition, predation, or disease) with other organisms that depend on rain could determine the distribution of red kangaroos C) Rainfall determines the distribution of red kangaroos D) Latitude determines the distribution of red kangaroos
B) Nothing, both rainfall and interactions (e.g. competition, predation, or disease) with other organisms that depend on rain could determine the distribution of red kangaroos
You have a hypothesis that the presence of a predator is responsible for explaining the distribution of an intertidal snail species. Which of the following would provide the best evidence for your hypothesis? A) Survey a large number of sites along the coast for the presence of predators and the presence of snails. If the presence of predators is correlated with the absence of snails this demonstrates that predators are responsible. B) Remove predators from a small set of sites along the coast. If removal of the predators results in an increase of snail abundance compared to unmanipulated control plots, this demonstrates that predators are responsible. C) A or B provide equally good evidence for the hypothesis that predators are responsible for explaining the distribution of the snail.
B) Remove predators from a small set of sites along the coast. If removal of the predators results in an increase of snail abundance compared to unmanipulated control plots, this demonstrates that predators are responsible.
q74 The map above describes the distribution of the Snub-Nosed, Spotted Kangaroo over the Australian Continent. Which factors listed most likely determine the kangaroo's distribution? A) A virus associated with the arid interior of the continent kills kangaroo populations so they tend not to occur there. B) Snub-Nosed, Spotted Kangaroos do best in arid, open grasslands, which tend to be found in the interior of the continent. C) Snub-Nosed, Spotted Kangaroos do best in deserts which are scattered across the western half of the continent. D) Snub-Nosed, Spotted Kangaroos do best in forested, wetter environments, which are found along the eastern coastline.
B) Snub-Nosed, Spotted Kangaroos do best in arid, open grasslands, which tend to be found in the interior of the continent.
Which of the following did not result in an increase in the per capita growth rate of the human population? A) The advent of modern medicine (antibiotics, vaccines) B) The demographic transition C) The advent of agriculture D) The Industrial Revolution E) None of the above, they all resulted in an increase in the per capita growth rate.
B) The demographic transition
As population density approaches the carrying capacity, which of the following happens? A) The per capita rate of increase will not change B) The per capita birth rate will decline, the per capita death rate will increase, or both C) The carrying capacity will decrease in response to the increased population size D) The population will crash
B) The per capita birth rate will decline, the per capita death rate will increase, or both
Which of the following is true of decomposers? A) They recycle chemical elements directly back to primary consumers B) They convert dead organisms from all trophic levels to chemical compounds usable by primary producers C) Some species are autotrophic, while others are heterotrophic D) They secrete enzymes that convert the organic molecules of detritus to CO2 and H2O
B) They convert dead organisms from all trophic levels to chemical compounds usable by primary producers
A kangaroo rat instinctively reacts to the sound of a rattlesnake by executing an escape jump. Which is most ultimate? A) The sound of the rattlesnake B) To produce more offspring C) Fear of rattlesnakes D) Aggression E) To avoid being killed
B) To produce more offspring
q32 The diagram above of is of a food web. The directions of the arrows indicate who eats who (the arrows point to who is eaten). If species F is a secondary consumer, what is species D most likely to be? A) an autotroph B) a predator C) a herbivore D) a tertiary consumer E) a primary consumer
B) a predator
q69 This question is based on the figure above. The population's growth rate was lowest: A) between 2000 and 2005 B) between 1994 and 2000 C) between 1985 and 1990 D) between 2003 and 2008
B) between 1994 and 2000
When thinking about the killer whale, sea otter, sea urchin and kelp example, we can consider the sea otter to be a(n): A) cooperative excluder B) keystone species C) community facilitator D) dominant species E) ecosystem engineer
B) keystone species
q69 This question is based on the figure above. The population model that best fits this population over the period 1984 - 2008 is _____, because ______. Be careful to distinguish between growth rate and population size. A) exponential; the population growth rate increases slowly but steadily. B) logistic; after a rapid increase to begin with, population size more or less levels off C) exponential; the population continues to grow in size. D) exponential; initially the population increases rapidly E) logistic; the population undergoes both increases and decreases in size.
B) logistic; after a rapid increase to begin with, population size more or less levels off
To recycle nutrients, the minimum an ecosystem must have is A) decomposers B) producers and decomposers C) producers D) producers, primary consumers, and decomposers E) sunlight
B) producers and decomposers
A small population of the cabbage white butterfly (Pieris rapae) has the same per capita rate of increase (r) as a different but larger population. If both populations are experiencing unlimited growth A) the two populations will add equal numbers of individuals per unit time B) the large population will add more individuals per unit time C) the small population will add more individuals per unit time D) the growth trajectories of the two populations will proceed in opposite directions E) the large population will cease growing but the small population will continue growing
B) the large population will add more individuals per unit time
Two tree species live and compete for space on the side of a steep Himalayan mountain. Species A is found high on the mountain, just below the permanent snow line, while Species B is found low on the mountain where the temperature is significantly warmer though all seasons. Removal experiments showed that Species A competitively excludes Species B from the upper part of the mountain. Further observations showed that Species A cannot survive low on the mountain because temperatures get too high in the late spring and its seedlings do not survive due to lack of water. Fill in the blanks. Species A's realized niche is ________ its fundamental niche and Species B's realized niche is _________ its fundamental niche. A) smaller than; larger than B) the same as; smaller than C) the same as; larger than D) larger than; smaller than E) larger than; the same as
B) the same as; smaller than
Two different populations of the same species have the same per capita rate of growth (r). If both populations are experiencing exponential growth A) the growth trajectories of the two populations will proceed in opposite directions B) the small population will add fewer individuals per unit time C) the large population will cease growing but the small population will continue growing D) the large population will approach the carrying capacity but the small population will continue growing E) the two populations will add equal numbers of individuals per unit time
B) the small population will add fewer individuals per unit time
q71 In the food chain above the arrows indicate the direction of energy transfer. This food chain does not exhibit a trophic cascade. Phytoplankton use energy from the sun to convert C02 into biomass. If the phytoplankton contain 1,100 grams of biomass per cubic meter of ocean, how many grams of biomass per cubic meter would you expect to find in the fish? A) 900 B) 1000 C) 11 D) 110 E) 990
C) 11
Which explanation of the following behavioral pattern provides the most ultimate cause for the behavior? A) A male robin attacks a red tennis ball because many times in the past red tennis balls have been thrown at it, and it has learned that tennis balls are hazardous. B) A male robin attacks a red tennis ball because hormonal changes in spring increase its aggression C) A male robin attacks a red tennis ball because he mistakenly believes that it is another male trying to steal his nesting territory.
C) A male robin attacks a red tennis ball because he mistakenly believes that it is another male trying to steal his nesting territory.
A bird species, the Blackcap, breeds in Germany. However, population A migrates west to overwinter in the UK, whereas population B migrates southwest to overwinter in Spain. Which of the following experimental designs is sufficient to determine whether this migratory behavior has a genetic basis? A) First capture adult birds from the UK and Germany. Bring them back to Germany where they can raise their offspring and perform their normal behaviors. Observe which direction their offspring attempt to migrate. B) First capture adult birds from the UK and Germany. Observe which direction individuals attempt to migrate. C) First capture adult birds from the UK and Germany. Take their offspring at birth and hand raise them in Germany, keeping them away from their parents and each other. Observe which direction the offspring attempt to migrate. D) First capture adult birds from the UK and Germany. Take their offspring at birth and hand raise them in Germany, keeping them away from their parents and each other. Allow the offspring to breed with one another (but not between population A and B) and hand raise their offspring. Observe which direction the offspring of the second generation attempt to migrate.
C) First capture adult birds from the UK and Germany. Take their offspring at birth and hand raise them in Germany, keeping them away from their parents and each other. Observe which direction the offspring attempt to migrate.
In class we discussed in detail a trophic cascade involving killer whales, sea otters, sea urchins, and kelp. When killer whales started feeding more frequently on sea otters, what happened to the kelp? A) It became more abundant in some places and less abundant in other places B) Its carrying capacity increased C) It became less abundant D) It became more abundant E) It was unaffected
C) It became less abundant
How has Earth's temperature changed in recent decades? A) It is already warmer than any time in the last 450,000 years B) The change is already larger than any to have occurred in Earth's past C) It has increased but the change is small compared to a glacial cycle D) There is no evidence for a systematic temperature change E) Earth is moving in the direction of a major glaciation
C) It has increased but the change is small compared to a glacial cycle
A female cat in heat urinates more often and in many places. Male cats congregate near the urine deposits and fight with each other. Which of the following is the most proximate cause of this behavior? A) The female cat learned the behavior from observing other cats B) Female cats that did this in the past attracted more mates C) It is a result of hormonal changes associated with her reproductive cycle D) It announces to males that she is in heat
C) It is a result of hormonal changes associated with her reproductive cycle
During the mating season, a male lyrebird builds a dance floor (a low mound of soil about eight feet in diameter) and sings elaborate songs consisting of a mashup of songs from other bird species while dancing and displaying its long tail feathers above its head. Hey, this is true! Which of the following is the most proximate cause of the male's elaborate song and dance? A) It shows the female lyrebird that the male is very healthy because he can spend so much time perfecting his songs. B) Lyrebirds that do this are more successful in mating and have more offspring. C) It is driven by instinct, which is triggered by hormonal changes that occur every mating season. D) It causes female lyrebirds to congregate which allows the male to pick the best female to mate with.
C) It is driven by instinct, which is triggered by hormonal changes that occur every mating season.
Which of the following statements is true? A) Populations will experience unlimited growth if the population size becomes very large B) Populations with exponential growth are better competitors C) Populations have the potential for unlimited growth when their population is very small D) All populations have the potential for unlimited growth but only some populations can sustain it indefinitely E) In exponential growth, the per capita rate of growth accelerates with time
C) Populations have the potential for unlimited growth when their population is very small
Which of the following best describes resource partitioning? A) Resources are divided equally between all members of a species B) Two species can coevolve to share the same niche C) Slight variations in niche allow similar species to coexist D) Competitive exclusion results in the exclusion of the inferior species
C) Slight variations in niche allow similar species to coexist
Which of the following is not true of the terrestrial carbon cycle? A) The largest reservoir of carbon is in the lower ocean B) The only carbon reservoir to make a net addition to the atmosphere is the previously unavailable carbon stored in fossil fuels C) The atmosphere is not a reservoir of available carbon D) Terrestrial and marine ecosystems are carbon sinks
C) The atmosphere is not a reservoir of available carbon
Gelada baboons and Belbada baboons are closely related species that live on mountain tops with cliffs in Ethiopia. Like Gelada baboons, Belbada baboons feed on grass. However, unlike Gelada baboons, Belbada baboons spend the wet season in the low lands where they eat seasonally abundant bananas and beetles. Belbada baboons depend on these lowland resources to supply energy and protein to support their bigger bodies. From these observations, we can conclude that: A) The two species of baboon share some abiotic requirements and have other abiotic requirements that are different. B) Gelada and Belbada monkeys are actually two populations of the same species. C) The two species of baboon share some biotic requirements and have other biotic requirements that are different. D) Gelada monkeys are more at risk of extinction due to competition for biotic resources with humans. E) The two species share some biotic requirements but differ in their abiotic requirements.
C) The two species of baboon share some biotic requirements and have other biotic requirements that are different.
Which of the following combinations of factors help best to explain the distribution of species? A) the amount of energy and the amount of matter B) the carrying capacity and the length of food chains C) abiotic factors and interactions with other species D) density dependent and independent factors E) trophic structure and abiotic factors
C) abiotic factors and interactions with other species
The intermediate disturbance hypothesis is the idea that A) secondary succession occurs after an intermediate disturbance, whereas primary succession occurs after a severe disturbance B) communities with intermediate levels of disturbance tend to have intermediate numbers of trophic links C) communities with intermediate levels of disturbance tend to have more species than communities with high or low levels of disturbance D) A and C E) B and C
C) communities with intermediate levels of disturbance tend to have more species than communities with high or low levels of disturbance
The species richness of a community can be measured by: A) counting the richness of resources available to species in the community B) making a list of all of the species in the community and determining how different they are from one another on a phylogenetic tree C) counting the number of species in the community D) counting the total number of individuals of all of the species in the community
C) counting the number of species in the community
look at q18 What effect does the pattern of births and deaths above have on a population? A) exponential growth B) density-dependent regulation C) extinction D) the population size will be the average of births and deaths E) fluctuating population size
C) extinction
In class we examined a population of birds (blackcaps) that breed in Germany but some of which migrate west to overwinter in the UK whereas the rest migrate southwest to Spain. The difference in the migratory direction of the birds was due to: A) imprinting B) optimal foraging C) genetics D) sexual selection E) learned behavior
C) genetics
Imagine that you are designing an experiment aimed at determining whether the initiation of migratory behavior is largely under genetic control. Of the following options, the best way to proceed is to: A) observe genetically distinct populations in the field and see if they have different migratory habits. B) collect individuals from each population, bring them into the laboratory, and determine which direction those individuals attempt to migrate toward. C) perform within-population matings with birds from different populations that have different migratory habits. Rear the offspring in the absence of their parents and observe the migratory behavior of the offspring.
C) perform within-population matings with birds from different populations that have different migratory habits. Rear the offspring in the absence of their parents and observe the migratory behavior of the offspring.
All of the following phrases could characterize a population except A) interacting individuals B) density C) species richness D) boundaries E) carrying capacity
C) species richness
q61 Which of the following is not true when the population density is at the point marked ** in the figure above? A) r = 0 B) r = b - d C) the population density at ** exceeds the carrying capacity D) the birth and death rates are density dependent E) None of the above, they are all true
C) the population density at * exceeds the carrying capacity Can't assume much about k (carrying capacity) here, just that births equal deaths at this population size (notice that this shows density dependence here) and so the population will not shrink or grow and this could be because of predators, disease etc.
You are most likely to observe primary succession when you visit a(n) A) a coral reef B) tropical rain forest C) volcano that has erupted D) recently burnt forest E) abandoned field
C) volcano that has erupted
True or false? Ice core data show that temperature and CO2 have been highly correlated going back at least 450,000 years from the present. This proves that CO2 causes global warming via the greenhouse effect A) False B) True
Correlation does not prove causation.
A population of 100 bacteria doubles every 15 minutes. How can you calculate what the population will be in one hour? A) 100 x 15 x 4 B) 100 x 2^60 C) 100 x 60 x 2 D) 100 x 2^4
D) 100 x 2^4 100 x 16= 1600
You are studying nitrogen cycling of a pond ecosystem. During your study, a flock of migrating geese stops over at the pond for several days. What would you need to know to measure the effect of the geese on the nitrogen balance (the amount of nitrogen) in your pond? A) How much biomass the geese ate and how much nitrogen was in the biomass eaten B) How much nitrogen the geese deposited in urine and feces C) How much energy was lost in nitrogen transfer from the pond organisms to the geese D) A and B E) A, B and C
D) A and B A) How much biomass the geese ate and how much nitrogen was in the biomass eaten B) How much nitrogen the geese deposited in urine and feces
In the intermediate disturbance hypothesis, why does the diversity of the community decline when disturbance occurs at a low frequency (i.e. disturbance does not occur often)? A) Because the species that are strong competitors, the "tortoises," never get established and so the community is dominated by "hares," who are faster at colonizing after disturbance. B) Because predators have time to establish large populations, in turn driving many species extinct. C) Because the species that are good colonizers, the "hares," compete strongly with other "hares" and few species survive. D) Because the species that are good colonizers, the "hares," are outcompeted by the "tortoises," who are stronger competitors.
D) Because the species that are good colonizers, the "hares," are outcompeted by the "tortoises," who are stronger competitors.
Of the following choices, which represents the most ultimate aspect of bird life history? A) A hormonal response due to day length leads to mating behavior B) A change in day length triggers a hormonal response C) Birds sense a change in the day length D) Breeding occurs most frequently in the spring due to increased survivability of offspring
D) Breeding occurs most frequently in the spring due to increased survivability of offspring
Which of the following is false about sexual selection: A) Male ornaments and coloration indicate the vigor of a male B) When males fight over territories, this is a form of sexual selection C) Females choose males with showy ornaments or coloration to maximize their number of offspring D) Characteristics of male ornamentation are an ultimate reason for females to choose them as a mate E) None of the above are false, they are all true
D) Characteristics of male ornamentation are an ultimate reason for females to choose them as a mate
Which of the following describes a successional process in which one organism makes the environment more suitable for another organism? A) Secondary environment creation B) Mutualism C) Facilitation D) Commensalism E) Primary environment creation
D) Commensalism
Which of the following statements about ecology is incorrect? A) Ecologists may study populations and communities of organisms B) Ecology spans increasingly comprehensive levels of organization, from individuals to ecosystems C) Ecological studies may involve the use of mathematics and computers D) Ecology is a discipline that is independent from natural selection and evolutionary history
D) Ecology is a discipline that is independent from natural selection and evolutionary history
A CU graduate student studies how nitrogen moves through the Okavango Delta, focusing on the way the nutrient cycles between the biotic and abiotic components of the system. We could consider the graduate student a/n: A) Behavioral ecologist B) Population ecologist C) Community ecologist D) Ecosystem ecologist
D) Ecosystem ecologist
Which of the following is true about innate behaviors? A) Innate behaviors tend to vary considerably among members of a population. B) Innate behaviors are limited to invertebrate animals. C) Genes have very little influence on the expression of innate behaviors. D) Innate behaviors are expressed in most individuals in a population across a wide range of environmental conditions.
D) Innate behaviors are expressed in most individuals in a population across a wide range of environmental conditions.
In class we discussed in detail a trophic cascade involving killer whales, which eat sea otters, which eat sea urchins, which eat kelp. When killer whales started feeding more frequently on sea otters, what happened to the kelp? A) It became diseased B) It became more abundant C) It had less sunlight D) It became less abundant
D) It became less abundant
How has Earth's temperature changed in recent decades? A) Earth is moving in the direction of a major glaciation. B) There is no evidence for a systematic temperature change. C) The change is already larger than any to have occurred in Earth's past. D) It has increased but the change is small compared to a glacial cycle. E) It is already warmer than any time in the last 450,000 years.
D) It has increased but the change is small compared to a glacial cycle.q32
For a hypothetical population of barn swallows in Boulder County, which of the following statements about carrying capacity (K) would be incorrect? A) K is decreased when insecticides are used to control an insect-born human disease, leading to a decrease in flying insects on which the swallows feed B) K is increased when an abandoned barn creates more nesting areas C) K is decreased when a golf course is built by buying several rural lots and demolishing the barns and buildings D) K is decreased when barn swallows immigrate from a nearby county, increasing competition E) K is increased when bats (a main competitor for food) are driven almost to extinction by a disease, increasing food availability
D) K is decreased when barn swallows immigrate from a nearby county, increasing competition
As population density approaches the carrying capacity (K), which of the following is most likely to happen? A) The per capita growth rate will approach a constant equal to K B) The carrying capacity will decrease in response to the increased population size C) The per capita rate of growth will become increasingly negative D) The per capita rate of growth will approach zero E) The per capita birth rate will increase, the per capita death rate will decline, or both
D) The per capita rate of growth will approach zero
You are most likely to observe secondary succession when you visit A) an area that was covered by a massive lava flow until recently. B) an abandoned black top parking lot. C) an area that was recently covered by a glacier that is now receding. D) a forest in which a low intensity fire burned.
D) a forest in which a low intensity fire burned.
In a tightly coupled trophic cascade with three levels off the coast of Macquarie Island in the sub Antarctic, killer whales feed on elephant seals, which feed on orange squid. Scientists noticed that killer whale numbers had started to increase noticeably. In turn they predicted: A) no change in the orange squid population because the predator is cascading. B) no change in the number of elephant seals but an increase in the orange squid population. C) a decline in the orange squid population. D) an increase in the orange squid population. E) an increase in the number of elephant seals.
D) an increase in the orange squid population.
Which of the following are biotic factors that could affect reproduction or survival? A) sunlight and water for photosynthesis B) nutrients for growth C) water for animals to drink D) diseases and parasites E) all of the above
D) diseases and parasites
The proximate causes of behavior are interactions with the environment, but behavior is ultimately shaped by: A) sexuality B) hormones C) pheromones D) evolution
D) evolution
look at food web The diagram above of is of a food web. The directions of the arrows indicate who eats who (the arrows point to who is eaten). Species D is not a very abundant species in the food web but when it is removed from the food web, species C, F, and G also disappear. We could characterize species D as a A) ecosystem engineer B) dominant species C) community facilitator D) keystone species E) cooperative excluder
D) keystone species
q32 Above is a diagram of a food web. The directions of the arrows indicate who eats whom (the arrows point to who is eaten). Species F is not a very abundant species in the food web but when Species F is removed the species richness of the rest of the food web is reduced from six to just two species. We could characterize species F as a(n) A) dominant species B) community facilitator C) ecosystem engineer D) keystone species
D) keystone species
Which of the following are important biotic factors that can affect the structure and organization of biological communities? A) temperature, water B) nutrient availability, soil pH C) precipitation, wind D) predation, competition
D) predation, competition
To recycle nutrients, the minimum an ecosystem must have is A) decomposers B) producers C) producers, primary consumers, and decomposers D) producers and decomposers E) sunlight
D) producers and decomposers
Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem? A) the trophic efficiency of the system B) the ecosystem's rate of primary production C) the location of the nutrient reservoirs in the system D) the rate of decomposition in the ecosystem
D) the rate of decomposition in the ecosystem
Which of the following is true about sexual selection: A) Females choose males with showy ornaments or coloration to maximize their number of offspring B) Characteristics of male ornamentation are an ultimate reason for females to choose them as a mate C) Fighting for nesting sites between males is a form of sexual selection D) All of the above E) A and C only
E) A and C only A) Females choose males with showy ornaments or coloration to maximize their number of offspring C) Fighting for nesting sites between males is a form of sexual selection
Which of the following (A-D) does not contribute to density-dependent regulation of populations? A) competition for territories B) competition for available water C) diseases that the population is susceptible to D) competition for nutrients E) A, B, C and D all contribute
E) A, B, C and D all contribute A) competition for territories B) competition for available water C) diseases that the population is susceptible to D) competition for nutrients
Which of the following is most correct? A) The fundamental niche of a species is usually smaller than its realized niche B) The realized niche of a species is often smaller than its fundamental niche C) A species can be excluded from part of its fundamental niche by a competitor D) Both A and C are correct E) Both B and C are correct
E) Both B and C are correct B) The realized niche of a species is often smaller than its fundamental niche C) A species can be excluded from part of its fundamental niche by a competitor
Which of the following is not true of ecosystems? A) Ecosystems consist of the community together with the abiotic environment of an area B) Energy and nutrients can pass from autotrophs to herbivores to carnivores C) Decomposers convert organic materials from all trophic levels to inorganic compounds usable by primary producers D) Decomposition connects all trophic levels E) Energy and nutrients are recycled
E) Energy and nutrients are recycled
The fundamental law of population dynamics states that A) populations are neither conserved nor destroyed; their energy is in balance and simply changes form B) populations are conserved when they are below the carrying capacity but destroyed when they are above the carrying capacity C) population growth depends fundamentally on the amount of energy available to the population D) population size goes up and down E) None of the above
E) None of the above
The species richness of a community is: A) the number of food chains present B) the energy content of all species C) the richness of resources available to the species D) the total number of all organisms E) None of the above
E) None of the above
Which of the following is true of the terrestrial carbon cycle? A) Terrestrial and marine ecosystems give off more carbon to the atmosphere than they take from the atmosphere. B) All of the carbon added to the atmosphere from fossil fuels stays in the atmosphere. C) The largest reservoir of carbon is in fossil fuels. D) The atmosphere is not a reservoir of carbon. E) None of the above are true, they are all false.
E) None of the above are true, they are all false.
A relationship between two species that is described as a commensalism: A) affects one species negatively but the other species neither positively or negatively. B) affects one species positively and the other negatively. C) affects both species positively. D) affects both species negatively. E) affects one species positively but the other species is neither positively nor negatively affected.
E) affects one species positively but the other species is neither positively nor negatively affected.
q32 Above is a diagram of a food web. The directions of the arrows indicate who eats whom (the arrows point to who is eaten). If species B is an herbivore, what is species C most likely to be? A) an autotroph B) a detritivore C) a secondary predator D) a predator E) an herbivore
E) an herbivore
Ecology as a discipline deals with all of the following levels of biological organization except: A) population. B) community C) organismal D) ecosystem E) cellular
E) cellular
Which of the following levels of organization is arranged in the correct sequence from most to least inclusive? A) individual, community, population, ecosystem B) individual, population, community, ecosystem C) community, ecosystem, individual, population D) population, ecosystem, individual, community E) ecosystem, community, population, individual
E) ecosystem, community, population, individual
The species richness of a community refers to the A) relative numbers of individuals in each species B) total number of all organisms C) number of food chains D) energy content of all species E) number of different species
E) number of different species
The energetic hypothesis is an explanation to account for A) the flow of energy in a food web B) the strength of trophic cascades C) the rate of nutrient cycling D) the carrying capacity of human populations E) the length of food chains
E) the length of food chains
Two barnacle species live and compete for space in the rocky intertidal zone. Cthamalus is found high in the intertidal zone, while Balanus is found low in the intertidal zone. Removal experiments showed that Balanus competitively excludes Cthamalus from the lower part of the intertidal zone. Further observations showed that Balanus cannot survive high on the rocks because it dries out during low tides. Fill in the blanks. Balanus's realized niche is ________ its fundamental niche and Cthamalus's realized niche is _________ its fundamental niche. A) larger than; smaller than B) smaller than; larger than C) larger than; the same as D) the same as; larger than E) the same as; smaller than
E) the same as; smaller than
