General Biology: BI101Spring, 2007
STUDY QUESTIONS: Ch 39
1. Which of the following processes would contribute to an increase in population size?
a. birthb. deathc. immigrationd. emigration
e. Both the first and third answers are correct.
2. The rate at which a population reproduces and grows under ideal or optimal conditions is known as the ______.
a. replacement-level fertilityb. biotic potentialc. carrying capacity
d. environmental resistancee. survivorship curve
4. The number of individuals of a particular species that the local environment will support is called ______.
a. biotic limitb. trophic levelc. biotic potential
d. carrying capacitye. ecological maximum
5. Currently, what is the approximate human population of the United States?
a. 125 millionb. 290 millionc. 376 milliond. 433 millione. 528 million
6. Which of the following areas has the highest human population growth rate, with a fertility rate of more than 2.5%?
a. Africab. Chinac. Central and South Americad. North Americae. Asia (excluding China)
7. If the number of births in a population is greater than the number of deaths, which of the following is correct?
a. The population is increasing in size.b. The population is decreasing in size.
c. The value for the rate of growth (r) is positive.
d. The value for the rate of growth (r) is negative.
8. The biotic potential of a species depends on which of the following factors?
a. the age at which the organism first reproduces
b. the chance of survival to the age of reproduction
c. the frequency with which reproduction occurs
d. the average number of offspring produced each time
e. the length of the reproductive life span of the organism
f. all of the above
9. Which of the following factors is least likely to influence population size in a density-dependent way?
a. predationb. competitionc. emigrationd. climate and weather
e. parasitism and disease
10. The biotic potential of a population is most likely to be achieved ______.
a. when the population is declining
b. when the population exceeds the carrying capacity
c. when the population is increasing but is near carrying capacity
d. when the population is small compared to the carrying capacity
e. The first two answers are both correct.
11. Assuming that birth rate and death rate for a population were equal, what would happen to population numbers if emigration exceeded immigration?
a. Population numbers would decrease.b. Population numbers would increase.
c. Abiotic components would dwindle.d. Abiotic components would flourish
12. Which of the following examples illustrates the principle of exponential growth?
a. a population of aphids whose population numbers decrease consistently from year to year
b. a population of spiders whose population numbers increase one year but decrease in other years
c. a population of spider mites whose population numbers double every two weeks for the course of the summer
d. a population of purseweb tarantulas whose population numbers remain essentially unchanged over time
13. Which of the following would NOT decrease the carrying capacity of an ecosystem?
a. depletion of nonrenewable resources
b. depletion of renewable resources occurring at a slower rate than the ability of a particular renewable resource to recover
c. depletion of renewable resources occurring at a rate that exceeds the ability of a particular renewable resource to recover
d. none of the above
14. How have humans been able to expand the carrying capacity over the course of recorded history?
a. through advances in technology and medicine
b. by co-opting the resources of other species
c. by exploiting renewable resources faster than they can be replaced and nonrenewable resources that cannot be replaced
d. all of the above
15. Why is the U.S. population rate growing as rapidly as it is despite the fact that its fertility rate is 2.03, below the replacement-level fertility of 2.1 children per female?
a. Even though our fertility rate is below RLF = 2.1, for many years after World War II the fertility rate exceeded the replacement level; therefore, the population is still going up because more women are reproducing.
b. emigrationc. immigrationd. Both the first and third answers are correct.
23. Label the portions of the S-curve of population growth graph on the left.
Answer:
Label A: equilibrium
Label B: exponential growth
Label C: carrying capacity
Label D: environmental resistance
Label E: biotic potential
24. Another way to look at populations is through survivorship curves. Label each of these curves as to survivorship.
Answer:
Label A: early loss
Label B: constant loss
Label C: late loss
25. Age-structure diagrams indicate the overall health of the population. Label the three diagrams below as to how the population is changing.
Answer:
Label A: expanding population
Label B: shrinking population
Label C: stable population
31. As the size of a snowshoe hare population rises, the number of deaths due to predation by lynx often also rises because ______.
a. the number of encounters between predators and prey will increase when there are more prey around
b. some of the lynx will switch from other prey like grouse to seeking out snowshoe hares as the latter's numbers increase
c. the increased food available to lynx will eventually increase the numbers of lynx by increasing their birth rate
d. all of the above
33. Your personal "ecological footprint" depends on ______.
a. the size of your house, how well it is insulated, and the climate in the region where you live
b. the types of transportation you use, how much you travel, and whether you travel alone or with a group
c. the types and amounts of foods you eat and how much you waste
d. how many goods you consume and the waste you produce
e. all of the above
BI101SQ Ch39.doc110/18/2018