BIO 100 CH 36 & 37

17) A tidal wave wipes out the entire population of mice living on an island. This is an example of A) Type III survivorship. B) a density-dependent effect. C) the effects of abiotic factors. D) the interaction between density-dependent and abiotic factors.

C) the effects of abiotic factors.

23) What is the age structure of a population? A) the curve that results when the likelihood of dying is plotted as a function of age B) the curve that results when the likelihood of being alive is plotted as a function of age C) the proportion of individuals alive in different age-groups D) the difference in the age distribution of a population at two different points in time

C) the proportion of individuals alive in different age-groups

30) Examine the age structure of Germany in the figure below. Which of the following statements is not supported by the age structure? A) There will be large positive population growth in the near future. B) There are more women than men between the ages of 60 and 70. C) There will be small negative population growth in the near future. D) There are more people between the ages of 25 to 39 then between 0 and 14.

A) There will be large positive population growth in the near future.

28) In an average ecosystem, about how much energy is present in the organisms at a given trophic level compared to the organisms at the next higher trophic level? A) a tenth as much B) half as much C) twice as much D) ten times as much

A) a tenth as much

13) Most plants have a variety of chemicals, spines, and thorns because the plants A) cannot run away from herbivores. B) feed on the organisms that try to eat them. C) are camouflaged into their surroundings. D) must rely on photosynthesis for food.

A) cannot run away from herbivores.

1) One predator avoidance mechanism that has evolved in prey is A) chemical defenses. B) secretion of digestive enzymes that hydrolyze glucose. C) secretion of enzymes that break down toxic plant compounds. D) development of a short gestation period.

A) chemical defenses.

3) The pattern of distribution for a certain species of kelp is clumped. The pattern of distribution for a population of snails that live on the kelp would be A) clumped. B) homogeneous. C) random. D) uniform.

A) clumped.

19) Which of the following accurately represents a food chain in the grasslands of Africa? A) grass, giraffes, lions, vultures, fungi B) grass, fungi, giraffes, vultures, lions C) grass, lions, giraffes, fungi, vultures D) grass, fungi, lions, vultures, giraffes

A) grass, giraffes, lions, vultures, fungi

16) Thanks to a new conservation program, a population with only 200 individuals at the beginning of the year is growing exponentially. The population has a per capita birth rate of 0.5 per year and a death rate of 0.2 per year. What is the growth rate during the year? What will the population be at the end of the year? A) growth rate = 60 per year; population = 260 B) growth rate = 6 per year; population = 206 C) growth rate = 260 per year; population = 60 D) growth rate = 30 per year; population = 230

A) growth rate = 60 per year; population = 260

23) A keystone species that is a predator will A) maintain the species diversity in a community. B) harvest prey species down to extinction. C) help many of its prey reproduce. D) reduce the diversity of the community

A) maintain the species diversity in a community.

14) In addition to abiotic factors, community composition of plants can be severely compromised by A) parasites and pathogens. B) introduction of chestnut trees. C) non-native birds. D) rapid coevolution.

A) parasites and pathogens.

7) A Type I survivorship curve is associated with which of the following life history traits? A) parents providing extended care for their young B) large numbers of offspring being produced C) infant mortality being much greater than adult mortality D) a short life span for most individuals

A) parents providing extended care for their young

1) A community is composed of A) potentially interacting populations of different kinds of organisms. B) one species of organism living in a specific environment on Earth. C) living organisms and their nonliving environment. D) the factors that constitute an organism's niche

A) potentially interacting populations of different kinds of organisms

10) Camouflage typically evolves as a result of A) predation. B) interspecific competition. C) mutualism. D) herbivory.

A) predation.

16) In a hypothetical food chain consisting of grass, grasshoppers, sparrows, and hawks, the grasshoppers are A) primary consumers. B) primary producers. C) secondary consumers. D) secondary producers

A) primary consumers.

27) For a given area and time period, the amount of solar energy converted to chemical energy in organic compounds is called A) primary succession. B) secondary succession. C) primary production. D) secondary production

A) primary succession.

9) Dinoflagellates are important to coral and coral-dwelling animals because they A) produce energy that is used by coral animals through photosynthesis. B) provide shelter for the fast-growing seaweeds associated with coral. C) produce CO2 and nitrogen for coral. D) are toxic to species that prey on reef-dwelling fish.

A) produce energy that is used by coral animals through photosynthesis.

29) One simple thing that you can do to help safeguard the environment is to eat a diet consisting only of organisms that are A) producers. B) primary consumers. C) secondary consumers. D) a mix of producers and consumers.

A) producers.

5) The density of Douglas firs in an old-growth forest is estimated by counting the Douglas firs in four sample plots of 1 hectare each. The number of fir trees in the plots is 10, 12, 7, and 11, respectively. What is the estimated density of firs in the forest? A) 5 trees per hectare B) 10 trees per hectare C) 20 trees per hectare D) 25 trees per hectare

B) 10 trees per hectare

21) Which of the following statements about human population growth is true? A) Human population size on Earth today is at equilibrium. B) Demographic transition is a transition from high birth rates and high death rates to low birth rates and low death rates. C) During a demographic transition, birth rates typically drop first due to the availability of reliable contraception. D) Human population size has increased faster and faster throughout human history.

B) Demographic transition is a transition from high birth rates and high death rates to low birth rates and low death rates.

12) If a population has a birth rate of 40 individuals per 1,000 per year and a death rate of 30 individuals per 1,000 per year, how will the population change each year? (Assume that the population is below carrying capacity and that there is no immigration or emigration.) A) It will decrease by 70%. B) It will increase by 1%. C) It will increase by 5%. D) It will increase by 100%.

B) It will increase by 1%.

13) What kind of curve represents exponential growth? A) ascending straight line B) J-shaped C) S-shaped D) descending straight line

B) J-shaped

6) Which of the following is an example of predation? A) a lizard's camouflage B) a hawk swooping down quickly to capture, kill, and eat a prairie king snake C) a goldfinch feeding on the seeds of a thistle plant D) the vivid colors of the poison-arrow frog in Costa Rica

B) a hawk swooping down quickly to capture, kill, and eat a prairie king snake

CHAPTER 36 1) Which of the following is an example of a population? A) all of the microorganisms on your skin B) all of the students in your classroom C) all students attending colleges and universities in your state D) the various plants found in prairies in the western United States

B) all of the students in your classroom

9) The maximum number of individuals a habitat can support is called its A) reproductive potential. B) carrying capacity. C) community size. D) density-dependent factor.

B) carrying capacity.

12) Some herbivore-plant interactions evolved through a series of reciprocal evolutionary adaptations in both species. This process is called A) herbivory. B) coevolution. C) selection. D) tropism

B) coevolution.

3) An owl and a hawk both eat mice. Which of the following describes the relationship between a hawk and an owl? A) predation B) competition C) mutualism D) parasitism

B) competition

18) Organisms that digest molecules in organic material and convert them into inorganic forms are A) primary consumers. B) decomposers. C) primary producers. D) detritivores.

B) decomposers.

8) A survivorship curve that involves producing very few offspring, each of which has a high probability of surviving to adulthood, is typical of A) sea stars. B) elephants. C) oysters. D) rodents.

B) elephants.

6) A survivorship curve is a A) graph that plots an individual's likelihood of reproducing as a function of age. B) graph that plots an individual's likelihood of being alive as a function of age. C) graph that shows the effect of predation on a prey population. D) model for population growth that incorporates the concept of carrying capacity.

B) graph that plots an individual's likelihood of being alive as a function of age.

19) An r-selected species typically A) offers considerable parental care to offspring. B) has an advantage in habitats that experience unpredictable disturbances. C) is large-bodied and long-lived. D) lives in stable climates.

B) has an advantage in habitats that experience unpredictable disturbances.

26) An ecological footprint A) is a means of determining increases in populations that lived in the past. B) is a means of understanding resource availability and usage. C) measures dispersion and adaptability. D) will estimate population movements.

B) is a means of understanding resource availability and usage.

25) The world human population A) is growing faster now than ever before. B) is growing, but at a slower rate than in the last century. C) has leveled off at carrying capacity. D) is starting to decline.

B) is growing, but at a slower rate than in the last century.

4) When two different populations in a community benefit from their relationship with each other, the result is called A) herbivory. B) mutualism .C) parasitism. D) competition.

B) mutualism

11) If an ecosystem has a carrying capacity of 1,000 individuals for a given species and 2,000 individuals of that species are present, we can predict that the population A) size will remain at equilibrium. B) size will decrease. C) will show a clumped dispersion pattern. D) size will slowly increase.

B) size will decrease.

21) The number of species in a community is called the A) species diversity. B) species richness. C) species population. D) species index

B) species richness.

17) In a food chain consisting of phytoplankton → zooplankton → fish → fishermen, the fishermen are A) secondary consumers. B) tertiary consumers. C) quaternary consumers. D) secondary producers

B) tertiary consumers.

7) The freshwater leech is an organism that feeds off of the blood of other organisms such as frogs andturtles. Which of the following describes the relationship between freshwater leeches and frogs or turtles? A) herbivory B) predation C) mutualism D) parasitism

D) parasitism

5) When a crocodile eats a fish, the interspecific interaction between the two could be expressed as________ for the crocodile and ________ for the fish. A) -; - B) +; + C) +; - D) -; +

C) +; -

28) According to this graph of the population growth of fur seals, in what year did the population first reach its carrying capacity? A) 1925 B) 1930 C) 1940 D) 1950

C) 1940

29) According to this graph of population growth in Mexico, in what year was the rate of population increase in Mexico the greatest? A) 1912 B) 1930 C) 1965 D) 2000

C) 1965

14) A population of deer has a per capita rate of increase of 0.1 deer per year. If there are initially 300 deer in the population, and the population is growing exponentially, how many deer will be in the population after one year? A) 30 B) 300 C) 330 D) 6003

C) 330

20) Which of the following statements regarding food webs is true? A) A consumer eats only one type of producer. B) Detritivores consume dead organic matter from a specific trophic level. C) Several species of primary consumers may feed on the same species of producer. D) energy transfer moves from producer to consumer and back

C) Several species of primary consumers may feed on the same species of producer.

20) Which of the following organisms best illustrates K-selection? A) the production of thousands of eggs every spring by frogs B) mice that produce three litters of 10-15 babies in the course of a summer C) a polar bear producing one or two cubs every three years D) a species of weed that quickly spreads into a region of cleared trees

C) a polar bear producing one or two cubs every three years

22) A demographic tool used to predict a population's future growth is A) a Type III survivorship curve. B) a demographic transition. C) age structures. D) a Type I survivorship curve.

C) age structures.

22) In your backyard you overturn a large rock. In the damp soil underneath the rock, you see various insects scurrying for cover: one black spider, five black ants, two brown beetles, and three gray pillbugs. In this community of organisms, species richness is represented by A) the ants, since there are more of them than any other organism. B) eleven total organisms. C) four different species of organisms. D) the ants and the spider equally, since they have the greatest number of organisms of the same color.

C) four different species of organisms.

10) A newly mated queen ant establishes an ant nest in an unoccupied patch of suitable habitat. The population of the nest grows quickly at first, then levels off at carrying capacity. Which of the following models best describes its population growth? A) linear B) logarithmic C) logistic D) exponential

C) logistic

24) The age structure of the United States in 2010 shows A) a broad base, suggesting a high birth rate. B) a broad base, suggesting a low birth rate. C) that a greater proportion of the population is elderly now than in earlier decades. D) that the United States has not yet gone through a demographic transition.

C) that a greater proportion of the population is elderly now than in earlier decades.

2) One reason it is important to understand community ecology is A) to understand the life cycle of fish, such as cichlids. B) for identification of stomach microbes. C) to aid in conservation of endangered species. D) to provide an enriched habitat for humans

C) to aid in conservation of endangered species.

4) You drive through Iowa in the spring and notice that along a stretch of several kilometers, every third fence post has a male redwing blackbird perched on it defending its nesting territory. This is an example of A) clumped dispersion. B) random dispersion. C) uniform dispersion. D) artificial dispersion.

C) uniform dispersion.

24) When a New England farm is abandoned, its formerly plowed fields first become weedy meadows, then shrubby areas, and finally forest. This sequence of plant communities is an example of A) evolution. B) a trophic chain. C) secondary succession. D) primary succession

D) primary succession

15) Which of the following statements regarding logistic growth is true? A) The parameter (K - N)/K is always equal to zero. B) There has to be more than one limiting factor in place for logistic growth to occur. C) Population growth is highest when the population is much larger than the carrying capacity. D) Population growth is zero when (K - N)/K is equal to zero.

D) Population growth is zero when (K - N)/K is equal to zero.

26) Which of the following processes does not occur in ecosystems? A) Energy flows through the system. B) Carbon is cycled between biotic and abiotic forms. C) Producers convert light energy to chemical energy. D) The energy source that powers the system is used by consumers to make organic compounds.

D) The energy source that powers the system is used by consumers to make organic compounds.

18) In the logistic growth model, as population size increases, birth rates A) remain constant and death rates increase. B) decline but death rates remain steady. C) and death rates increase. D) decline and/or death rates increase.

D) decline and/or death rates increase.

2) Assume that there are five alligators per acre in a swamp in northern Florida. This is a measure of the alligator population's A) dispersion. B) intrinsic rate of increase. C) range. D) density.

D) density

25) The flow of ________ into ecosystems occurs in one direction only, while ________ are recycledwithin the ecosystem itself. A) minerals; energy compounds B) genetic information; genotypes C) organic compounds; minerals D) energy; chemicals

D) energy; chemicals

8) The sum total of a population's use of the biotic and abiotic resources of its habitat constitutes its A) environment. B) evolution. C) range. D) niche.

D) niche.

15) Within an ecosystem, a tree is a A) secondary consumer. B) detritivore. C) primary consumer. D) producer

D) producer

27) Which of the following activities would result in a decrease in your ecological footprint? A) flying across the United States once a month B) driving your car to and from school every day C) leaving the water running while you brush your teeth D) taking a city bus instead of driving to work

D) taking a city bus instead of driving to work

30) Which trophic level in this food chain represents the secondary consumer? A) trophic level A B) trophic level B C) trophic level C D) trophic level D

D) trophic level D