Bio 100 Exam 4

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Question 1

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A mass extinction is?


Answers:	a. global in scale
	b. responsible for the death of many different groups of organisms
	c. always caused by human activity
	d. a and b above are correct

Question 2

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A relatively small natural area with an exceptionally large number of species living in it, is a?


Answers:	a. biological impossibility
	b. biodiversity hotspot
	c. mass extinction
	d. viable population

Question 3

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Which of the following could help to reduce the level of carbon dioxide in the environment?


Answers:	a. plant more trees
	b. reduce our use of fossil fuels
	c. driving more fuel efficient cars
	d. all of the above

Question 4

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How can the loss of any particular species have an economic impact on humans?


Answers:	a. they could be directly harvested for products
	b. they could contain potential genetic diversity for future breeding
	c. they could be useful as biological control agents
	d. all of the above could be true

Question 5

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In human populations, a decrease in death rate is usually later followed by a decrease in birth rate, but the time lag between these two events is called?


Answers:	a. a demographic transition
	b. carrying capacity
	c. a population pyramid
	d. bad news for everyone!

Question 6

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The first species to live on new land, such as that formed from volcanic lava, are called …….?


Answers:	a. climax community
	b. keystone species
	c. foundation species
	d. pioneer species

Question 7

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A diagram showing a summary of the numbers and proportions of individuals of each sex and age group in a population or country is called ?


Answers:	a. a population pyramid
	b. demographic momentum
	c. net primary productivity
	d. a demographic transition

Question 8

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What is demographic momentum?


Answers:	a. the time lag between when humans reduce birth rates and when population growth begins to slow
	b. the number of generations it takes for a population to reach zero population growth
	c. the time between the reduction in death rates and the reduction in birth rates
	d. the time when the world’s human population will reach 20 billion

Question 9

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Why is it bad if humans put more nutrients into the environment than are naturally there?


Answers:	a. they contribute to acid rain
	b. they contribute to global warming
	c. they contribute to eutrophication
	d. they do all of the above

Question 10

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A population that is growing exponentially increases?


Answers:	a. by the same number of individuals each generation
	b. by a constant proportion each generation
	c. in some years and decreases in others
	d. never

Question 11

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A group of interacting individuals of a single species located within a particular area is?


Answers:	a. a biosphere
	b. an ecosystem
	c. a population
	d. a community

Question 12

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Which of the following biomes is characterized by short growing seasons?


Answers:	a. deserts
	b. tropical wet forests
	c. Arctic tundra
	d. savanna

Question 13

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What is estimated to be the current world human population growth rate?


Answers:	a. – 0.7 %
	b. +2.5 %
	c. +1.7 %
	d. +1.2 %

Question 14

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A forest fire is an example of ________________ regulation.


Answers:	a. density-dependent
	b. density-independent
	c. r-selected
	d. k-selected

Question 15

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What is it called when individuals in a population are evenly spaced in their habitat?


Answers:	a. clumped
	b. uniform
	c. random
	d. exponential

Question 16

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Which cause of extinction results from humans’ direct use of a species?


Answers:	a. overexploitation
	b. habitat fragmentation
	c. pollution
	d. global warming

Question 17

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In the “Population Paradox” film, what single factor has been most responsible for Kenya’s population pyramid being turned upside down, with more old people surviving than the young?


Answers:	a. Civil war
	b. Famine
	c. Mass immigration
	d. HIV/AIDS

Question 18

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The number of currently described species on Earth is about………?


Answers:	a. 1.5 million
	b. 10 million
	c. 150,000
	d. 17,000

Question 19

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Another human-induced cause of extinction, like habitat loss, is?


Answers:	a. pollution
	b. overexploitation
	c. introduction of exotic species
	d. all of the above

Question 20

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Bees being indispensable pollinators of many plants, including human crops, is a classic example of?


Answers:	a. a predator-prey relationship
	b. mutualism
	c. the competitive exclusion principle
	d. a keystone species

Question 21

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An example of an invasive species that was recently introduced to the tiny Pacific island of Guam, and caused many local extinctions is?


Answers:	the domestic cat
	the bald eagle
	the polar bear
	the brown tree snake

Question 22

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What is the human population of Earth projected to be in 2050, according to the UN?


Answers:	a. 2050 million
	b. about 3 billion
	c. over 10 billion
	d. 14 million

Question 23

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The majority of water found on Earth is:


Answers:	a. ice
	b. water vapor
	c. fresh water
	d. salt water

Question 24

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A species that has a large effect on a community relative to its abundance is called a


Answers:	a. predator
	b. herbivore
	c. keystone species
	d. dominant species

Question 25

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Which of the following is a density-dependent factor that can limit population growth?


Answers:	a. lack of suitable habitat
	b. pollutants
	c. pesticides
	d. weather fluctuations

Question 26

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Species that have many offspring at one time are usually:


Answers:	a. r-selected
	b. k-selected
	c. both r- and k-selected
	d. not selected

Question 27

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The growth of human populations over the past 150 years is primarily due to?


Answers:	a. increases in the death rate
	b. decreases in the birth rate
	c. decreases in the death rate
	d. increases in net primary productivity

Question 28

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What kind of ecosystem are exotic species especially threatening to?


Answers:	a. deserts
	b. marine ecosystems
	c. islands
	d. tropical forests

Question 29

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The maximum population size that can be supported indefinitely by an environment is the


Answers:	a. maximum increase
	b. carrying capacity
	c. exponential growth
	d. population balance

Question 30

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What amount of energy is transferred between trophic levels in a typical food chain?


Answers:	a. 100%
	b. 1%
	c. 10%
	d. 13%

Question 31

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Why is the tundra treeless?


Answers:	a. lack of sufficient water
	b. permanently frozen ground
	c. winters too harsh
	d. too many fires

Question 32

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The study of the interaction among organisms and between organisms and their environment is defined as?


Answers:	a. ecology
	b. population biology
	c. demography
	d. climatology

Question 33

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Pollination is an example of…….?


Answers:	a. a possible source of new drugs
	b. chemical diversity
	c. an ecosystem service
	d. crop pest control

Question 34

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What would be the best way to estimate human population size?


Answers:	a. mark and recapture studies
	b. count the number of houses and then extrapolate
	c. do a basic census
	d. do aerial photography and extrapolate

Question 35

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A key feature of estuaries is:


Answers:	a. low light conditions and high productivity
	b. salt water and fresh water
	c. frequent algal blooms
	d. little or no vegetation

Question 36

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What is nitrogen fixation?


Answers:	a. the process by which gaseous nitrogen in air is converted to a form that plants can use
	b. fixing the levels of nitrogen to the levels that we had in 1960
	c. the process by which nitrogen runs into water and kills fish
	d. none of the above

Question 37

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A population begins to grow slowly, then at a very rapid rate, and finally levels off at a stable number. This pattern is an example of?


Answers:	a. a tightly linked cycle
	b. a J-shaped or exponential population curve
	c. a population crash
	d. an S-shaped or logistic population curve

Question 38

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The current population of the US is only about 5% of the world’s population, but as a society we consume approximately how much of the world’s resources?


Answers:	a. 1%
	b. 5%
	c. 25%
	d. 75%

Question 39

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Which of the following methods will provide the best information about both the size and density of a population?


Answers:	a. mark and recapture
	b. mark and release
	c. quadrat
	d. life table

Question 40

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In the film “Population Paradox”, what country has been undergoing such negative population growth and a predominantly aging society, such that they soon will not have enough population to support their economy?


Answers:	a. Kenya
	b. Sweden
	c. Japan
	d. India

Question 41

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Which factor is associated with recent declines in some country’s population growth rate?


Answers:	a. an increase in women’s social status
	b. an increase in female educational level
	c. an increase in per capita income
	d. all the above

Question 42

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Which mass extinction is famous since it was responsible for the extinction of the dinosaurs?


Answers:	a. the terminal Devonian extinction
	b. the end of the Permian extinction
	c. the end of the Triassic extinction
	d. the Cretaceous-Tertiary (or K-T) boundary extinction

Question 43

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A symbiotic relationship where both of the co-existing species benefit from the interaction is called ……?


Answers:	a. commensalism
	b. parasitism
	c. mutualism
	d. communism

Question 44

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Which of the following is considered a prime example of a keystone species in the Yellowstone National Park ecosystem in the US.


Answers:	a. the redwood tree
	b. the elk
	c. the beavers
	d. the wolf

Question 45

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Current rates of species extinction appear to be _______ historical (background) rates of extinction.


Answers:	a. equal to
	b. much greater than
	c. much less than
	d. just a little bit more than

Question 46

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According to some, the most effective way to reduce the current rate of extinction is to?


Answers:	a. preserve habitat, especially in highly diverse areas
	b. eliminate the risk of genetic drift
	c. focus on a single species at a time
	d. build more zoos

Question 47

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One of the major effects of an increase in atmospheric carbon dioxide is


Answers:	a. global warming
	b. a cooler than average climate
	c. an increase in acid rain
	d. a decrease in plants’ ability to photosynthesize

Question 48

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Species that are purposely or accidentally introduced to new geographic regions


Answers:	a. can become serious pests by killing the native species or reproducing very quickly
	b. usually quickly die out
	c. frequently form hybrids with native species
	d. experience increased mutation rates that help them adapt to the new ecosystem

Question 49

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What is eutrophication?


Answers:	a. a complete lack of nutrients in rainforest soils
	b. excess nutrients, in the form of fertilizer, washing from soils into waterways and causing excessive algal or plant growth
	c. the process whereby large tracts of natural forest are fragmented into smaller pieces, impacting the wildlife in them
	d. the accumulation of nitrogen gas in the atmosphere causing global warming