CH36-POPULATION ECOLOGY

The greatest crisis ever faced by humans is probably A) the ozone hole. B) global warming. C) hazardous waste disposal. D) air and water pollution. E) human population growth.

E

If most of the individuals of a human population are in their pre-reproductive years, you would expect the population size to ________ after 20 years. A) stay the same B) increase C) decrease D) decrease and then stabilize

B

A Type I survivorship curve is the result of which of the following life-history traits? A) Parents provide extended care for their young. B) Large numbers of offspring are produced. C) Infant mortality is much greater than adult mortality. D) Death rates are constant over the life span. E) Most individuals have short life spans.

A

The type of growth illustrated by the human race during the past 2,000 years is __________ growth. A) exponential B) logistic C) equilibrial D) Z-shaped E) linear

A

Which of the following is not an example of a population? A) all of the organisms in your classroom B) all of the students in your classroom C) all of the female students in your classroom D) all of the male students in your classroom E) all of the people who study with you

A

A test tube is inoculated with 1 x 103 cells of a bacterial strain that has a generation time of 30 minutes. The carrying capacity of the test tube for this strain is 6 x 109 cells. What will the bacterial population be after 90 minutes of culturing? A) 3 x 103 B) 8 x 103 C) 9 x 103 D) 1 x 109 E) 1 x 1012

B

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

Consider a stable frog population living at carrying capacity in a pond. If an average female produces 6,000 eggs during her lifetime and an average of 300 tadpoles hatch from these eggs, how many of these tadpoles will, on average, survive to reproduce? A) 0 B) 2 C) 10 to 20 D) 100 E) more than 100

B

Guppies from Trinidad form two distinct populations that differ in several life history traits that appear to relate to the local predator populations, pike-cichlids or killifish. Which of the following experiments would test the heritability of these traits? A) Raise both populations with cichlids to see if the population of smaller, faster-maturing guppies reproduces more quickly. B) Raise both populations without predators to see if they maintain their life history traits. C) Introduce cichlids into a habitat with killifish. D) Provide additional food to the guppies from cichlid habitats to see if they will grow to the same size as guppies from the killifish habitat.

B

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 70%. E) It will increase by 100%.

B

In terms of population dynamics, what is "boom-and-bust" cycling? A) a situation in which the movement of limiting nutrients through an ecosystem is pulsatile rather than steady B) a situation in which a population oscillates around the carrying capacity of its environment C) a situation in which a growing population overshoots the carrying capacity of its environment and experiences a crash before stabilizing D) a situation in which sex ratios in a population exhibit reciprocal oscillations E) a situation in which a predator species and a prey species cause oscillations in each other's populations

B

The age structure diagram of a human population in a developed country like Sweden, which has a population growth rate near zero and in which neither birth rate nor death rate has changed much in the past lifetime, has the shape of A) an hourglass. B) a pyramid. C) a rectangle tapering near the top. D) a funnel. E) a triangle with the point at the bottom.

B

The death by bubonic plague of about one-third of Europe's population during the fourteenth century is a good example of A) abiotic factors limiting population size. B) a density-dependent effect. C) a time lag. D) a density-independent effect. E) carrying capacity.

B

The human population on Earth is expected to reach 9.5 billion people by A) 2015. B) 2050. C) 2093. D) 3150.

B

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

B

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

Which of the following is most clearly a case of density-dependent population regulation? A) the summer drying of savanna grass for an insect that feeds on grass sap B) a dangerous new flu strain that is transmitted among humans by sneezing C) the first hard frost of fall for a population of annual morning-glory vines D) the growth of shade trees for a population of sun-loving shrubs in an abandoned field E) the occurrence of rainstorms for an opportunistic desert annual

B

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

Which of the following statements about the human population is false? A) The human population on Earth today is more than 6 billion people. B) Water use has remained about the same over the last 50 years. C) Countries vary greatly in their available ecological capacity. D) Humans continue to suffer from overpopulation and overconsumption. E) Humans living in the United States today use more than four times their share of available ecological capacity.

B

A country with an age structure diagram with a base smaller than most of the next higher levels is experiencing A) a population explosion. B) near zero population growth. C) negative population growth. D) logistic growth. E) exponential growth.

C

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

In a developing nation, such as the United States during the nineteenth and early twentieth centuries, the introduction of public health improvements such as sewage systems, milk pasteurization, and childhood vaccination would have changed the shape of the age structure diagram in what way? A) All levels of the pyramid would get wider by an equal amount. B) The pyramid would widen disproportionately at the base. C) The middle levels of the pyramid would widen disproportionately. D) The upper levels of the pyramid would widen disproportionately. E) The pyramid would get taller as people lived to ages not previously attained.

C

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

The density of Douglas firs in an old-growth forest is estimated by counting the Douglas firs in four sample plots of one 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) 2.5 trees per hectare B) 5 trees per hectare C) 10 trees per hectare D) 20 trees per hectare E) It cannot be determined without knowing the size of the forest.

C

To obtain optimal production in a small garden, one should A) plant seeds in rows with minimal spacing between rows. B) plant seeds in clumps with large spaces between clumps. C) plant seeds in a uniform pattern throughout the garden. D) soak seeds overnight before planting in rows. E) sow seeds randomly throughout the garden.

C

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

Which of the following statements about human demographic trends is true? A) As women's status and education increase, they choose to have more children. B) After 1950, mortality rates increased rapidly in most developing countries. C) A human population in which women reproduce at an later age will experience slower population growth. D) The movement from high birth rates and low death rates to low birth rates and high death rates is called the demographic transition.

C

A newly mated queen ant establishes an ant nest in an unoccupied patch of suitable habitat. Assuming that no disasters strike the nest, which of the following types of equation is likely to best describe its population growth? A) linear B) quadratic C) logarithmic D) logistic E) exponential

D

Which of the following statements about insecticides is true? A) To control agricultural pests, pest management uses biological controls, chemicals, or cultural methods, but never a combination of these. B) Simply killing many individuals is often the best way to reduce the size of a pest population. C) Most insecticides kill the pest but not the pest's natural predators. D) Prey species often have a higher reproductive rate than do predators.

D

You drive through Iowa in the spring and notice that every fence post for 3 km has a male redwing blackbird on it defending its nesting territory. This is an example of A) more birds than we need. B) clumped distribution. C) random distribution. D) uniform distribution. E) artificial selection.

D

An ecologist hypothesizes that predation by a particular owl species is the major factor controlling the population of a particular rabbit species. If this hypothesis proves to be correct, which of the following population effects could be expected in this rabbit-owl pair? A) A fall in the owl population should cause a fall in the rabbit population. B) A fall in the rabbit population should cause an increase in the owl population. C) An increase in the incidence of disease in the rabbit population should not change the owl population. D) An increase in the rabbits' food supply should not change the owl population. E) An increase in the owl population should cause a fall in the rabbit population

E

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

E