1.	Hypotheses can only be tested by doing experiments.	
A)	True	
B)	False	

2.	Let's say you feel very strongly that cigarette smoke does not increase the probability of getting cancer, and you base your view on something you read on the Internet. This is a good example of a(n):	
A)	observation	
B)	hypothesis.	
C)	theory.	
D)	experiment.	
E)	None of the other answer options is correct.	

3.	Many salmon return to the place where they were born to lay eggs. You hypothesize that they use visual cues to find their way back. To test your hypothesis, you blind salmon and then examine whether or not they are able to return to their birthplace. You find that they are unable to find their way back. From this experiment, you:	
A)	have proved your hypothesis.	
B)	have rejected your hypothesis.	
C)	supported your hypothesis.	
D)	can't determine whether your hypothesis is supported or not.	
E)	developed a theory about the role of vision in salmon navigation.	

4.	In the 1600s, Francesco Redi demonstrated that living organisms come from other living organisms. However, it would be inaccurate to say that Redi supported his hypothesis because:	
A)	his experiment only investigated a single kind of meat.	
B)	his experiment was done so long ago.	
C)	his experiment was based on observations.	
D)	his experiment only investigated a single organism.	
E)	his experiment didn't have the proper controls.	

5.	Which of the following CORRECTLY reflects the process of science?	
A)	Observation ® hypothesis formulation ® question ® experiment ® prediction	
B)	Observation ® question ® hypothesis formulation ® experiment ® support or refute hypothesis	
C)	Observation ® question ® hypothesis formulation ® experiment ® prove or disprove hypothesis	
D)	Observation ® question ® experiment ® hypothesis formulation ® prove or disprove hypothesis	
E)	Observation ® question ® experiment ® hypothesis formulation ® support or refute hypothesis	

6.	An explanation supported by a large body of observations and experimentation is referred to as a(n):	
A)	prediction.	
B)	theory.	
C)	hypothesis.	
D)	supposition.	
E)	investigation.	

7.	Observations allow scientists to draw tentative explanations called hypotheses.	
A)	True	
B)	False	

8.	What is a hypothesis?	
A)	the same thing as an unproven theory	
B)	a tentative explanation that can be tested by experiments	
C)	a verifiable observation	
D)	an experiment that leads to a prediction	
E)	None of the other answer options is correct.	

9.	When carrying out a controlled experiment, it is important to:	
A)	change multiple variables at once to see the full effect of the variables.	
B)	subject different groups to different conditions.	
C)	change only one variable at a time.	
D)	All of these choices are correct.	

10.	A hypothesis is considered a theory when the:	
A)	results of a single experiment support the hypothesis.	
B)	hypothesis has been revised many times.	
C)	results of several experiments do not support the hypothesis.	
D)	results of several experiments support the hypothesis.	

11.	Which one of the following is NOT part of the scientific method?	
A)	experimentation	
B)	observation	
C)	prediction	
D)	assumption	
E)	hypothesis	

12.	Asking and answering questions about the world in an unbiased manner is referred to as:	
A)	experimentation.	
B)	hypothesizing.	
C)	theorizing.	
D)	observation.	

13.	Evidence for the extinction of the dinosaurs approximately 65 million years ago comes from meteorites containing:	
A)	iridium.	
B)	palladium.	
C)	carbon.	
D)	silicon.	
E)	plutonium.	

14.	Which of the following scientists tested the hypothesis that microorganisms can arise by spontaneous generation?	
A)	Elena and Lenski	
B)	Redi	
C)	Pasteur	
D)	Darwin	
E)	Alvarez	

15.	The feature of an experiment that is changed from one treatment to the next is referred to as a(n):	
A)	variable.	
B)	control.	
C)	test group.	
D)	observation.	

16.	In some experiments, several identical groups are set up, keeping conditions similar among them. In the _____ group, a change is deliberately introduced. In the _____ group, this change is not introduced. In this way, the researcher can determine if the change has an effect.	
A)	control; test	
B)	test; control	
C)	null; variable	
D)	variable; null	

17.	Which one of the following is NOT a way in which biology is typically approached?	
A)	biomechanics	
B)	physiology	
C)	astrology	
D)	cognition	
E)	behavior	

18.	How many experiments have been conducted worldwide to test Darwin's initial hypothesis regarding natural selection?	
A)	1	
B)	50	
C)	100	
D)	500	
E)	thousands	

19.	A tentative explanation based on observation is referred to as a hypothesis.	
A)	True	
B)	False	

20.	A controlled way of asking and answering unbiased questions about the world is called a(n) _____.	

21.	A general explanation of the world supported by a large body of experiments and observations is called a(n) _____.	

22.	In the context of the scientific method, the words theory and hypothesis can be used interchangeably.	
A)	True	
B)	False	

23.	The crater believed to be the site of the meteor impact that caused the extinction of the dinosaurs is on the coast of:	
A)	Alaska.	
B)	Kenya.	
C)	Mexico.	
D)	India.	
E)	China.	

24.	A single experiment or observation can _____ a hypothesis.	
A)	reject	
B)	support	
C)	prove	
D)	reject or support	
E)	reject or prove	

25.	In the scientific method, hypotheses lead MOST directly to:	
A)	predictions.	
B)	theories.	
C)	experiments.	
D)	observations.	
E)	conclusions.	

26.	Which one of the following statements about hypotheses is INCORRECT?	
A)	Hypotheses make predictions about observations not yet made.	
B)	A collection of related hypotheses that endures repeated testing is called a theory.	
C)	Hypotheses can be tested by experiments or by making additional observations.	
D)	Hypotheses that provide reasonable explanations do not need to be tested.	
E)	All of the above statements about hypotheses are correct.	

27.	The strongest evidence that a meteor impact is responsible for dinosaurs becoming extinct is provided by:	
A)	the detection of high levels of radioactivity in the fossilized remains of dinosaurs from the time period corresponding to the extinction.	
B)	the presence of significant levels of iridium in the rock layers corresponding to the time of dinosaur extinction.	
C)	contamination of fossils from that time period with fragments of rock that penetrated the skeletons of many dinosaurs.	
D)	high levels of particulate matter in the lungs of dinosaur specimens perfectly preserved in ice.	
E)	None of the evidence presented supports a meteor impact being responsible for the extinction of the dinosaurs.	

28.	A boy observes a robin outside of his window.  He notices the robin repeatedly cocks its head to one side before pecking the ground.  The boy suspects that when the robin cocks its head it is actually listening for worms or insects underground.  His explanation of the bird's behavior is an example of:	
A)	a hypothesis.	
B)	an observation.	
C)	an experiment.	
D)	a theory.	
E)	both a hypothesis and a theory.	

29.	A boy observes a robin outside of his window.  He notices the robin repeatedly cocks its head to one side before pecking the ground.  The boy suspects that when the robin cocks its head it is actually listening for worms or insects underground.  How could the boy test his hypothesis about robins and worms?	
A)	He could count how many times a single robin catches a worm after it cocks its head and pecks the ground.	
B)	He could catch a robin and place it in an enclosure without worms or insects, and observe whether the robin still cocks its head.	
C)	He could observe several robins, and see if they all exhibit the same head-cocking and worm-catching behavior.	
D)	All of these experiments would test the boy's hypothesis.	

30.	A boy observes a robin outside of his window.  He notices the robin repeatedly cocks its head to one side before pecking the ground.  The boy suspects that when the robin cocks its head it is actually listening for worms or insects underground.  If the boy notes that a single robin routinely catches a worm after cocking its head, would this observation prove his hypothesis to be correct?	
A)	No, as this is only a single observation.	
B)	Yes, and no further experiments are needed.	
C)	Yes, but further experiments are needed.	
D)	No, as this would prove the boy's hypothesis is incorrect.	
E)	No, this observation would only support the boy's hypothesis, but not prove it.	

31.	Theories typically rely on a single hypothesis tested several times; theories do not take into consideration multiple hypotheses.	
A)	True	
B)	False	

32.	When you eat a hamburger, some of the energy in the food is converted to ATP that your cells can use to do all kinds of work, some of the energy is stored for later use, and some of the energy is dissipated as heat. The amount of energy before and after eating the hamburger is the same. This illustrates the:	
A)	first law of thermodynamics.	
B)	second law of thermodynamics.	
C)	theory.	
D)	the theory of evolution.	
E)	central dogma.	

33.	When you eat a hamburger, some of the energy in the food is converted to ATP that your cells can use to do all kinds of work, some of the energy is stored for later use, and some of the energy is dissipated as heat. You can only make use of a portion of the energy available in the hamburger because the rest is lost as heat. This is a consequence of the:	
A)	first law of thermodynamics.	
B)	second law of thermodynamics.	
C)	cell theory.	
D)	theory of evolution.	
E)	central dogma.	

34.	Which one of the following is a primary component of BOTH living organisms and the Earth's crust?	
A)	silicon	
B)	hydrogen	
C)	oxygen	
D)	carbon	
E)	nitrogen	

35.	When small molecules are linked together to form larger molecules, the increase in entropy typically comes from:	
A)	light.	
B)	heat.	
C)	work.	
D)	gas.	
E)	enzymes.	

36.	Which one of the following is characteristic of all living organisms and all nonliving material?	
A)	the capacity to evolve	
B)	the ability to reproduce	
C)	complexity, with spatial organization of several levels	
D)	the ability to change in response to the environment	
E)	subject to the basic laws of chemistry and physics	

37.	The first law of thermodynamics states that the degree of disorder in the universe tends to increase.	
A)	True	
B)	False	

38.	Which is an example of the first law of thermodynamics?	
A)	melting ice in your hand	
B)	making a house of playing cards	
C)	a dead battery	
D)	placing marbles in a row	

39.	Which is an example of the second law of thermodynamics?	
A)	setting up dominos in a row	
B)	knocking over a house of cards	
C)	touching a hot stove	
D)	applying the brakes in your car	

40.	All organisms use which of the following molecules to carry out metabolic reactions?	
A)	glucose	
B)	DNA	
C)	ATP	
D)	RNA	
E)	None of the other answer options is correct.	

41.	Compared to nonliving things, living organisms are characterized by which of the following?	
A)	Living organisms are made up of elements not found in nonliving things.	
B)	Living organisms are not subject to the laws of physics.	
C)	Living organisms are not subject to the laws of chemistry.	
D)	Living organisms have the capacity to evolve.	

42.	The energy before a chemical reaction and the energy after a chemical reaction is the same. This is an example of:	
A)	the first law of thermodynamics.	
B)	the second law of thermodynamics.	
C)	evolution by natural selection.	
D)	the scientific method.	

43.	Because water is so abundant on Earth, oxygen and hydrogen make up a majority of the known matter of the universe.	
A)	True	
B)	False	

44.	Living systems differ from nonliving systems in that energy not used to do work is lost as heat, reducing the total amount of energy in the universe.	
A)	True	
B)	False	

45.	Which one of the following elements is found in nonliving systems but not found in more than trace amounts in living systems?	
A)	calcium	
B)	carbon	
C)	hydrogen	
D)	oxygen	
E)	silicon	

46.	Entropy can be thought of as the amount of _____ in a system.	

47.	Which one of the following statements about the laws of thermodynamics is INCORRECT?	
A)	Highly organized living organisms like animal cells are exceptions to the second law of thermodynamics.	
B)	The addition of energy increases the disorder of a system.	
C)	In order to comply with the first law of thermodynamics, the conversion of energy from one form to another in biological reactions is 100 percent efficient.	
D)	All of these statements about the laws of thermodynamics are incorrect.	

48.	In Pasteur's experiment showing that living organisms arise from other living organisms, which one of the following statements MOST accurately describes Pasteur's hypothesis?	
A)	Straight-neck flasks allow for more contamination than swan-neck flasks.	
B)	Sterilization of broth kills microbes.	
C)	If microbes arise from nonliving matter, they should appear spontaneously in sterile broth.	
D)	Microbes should be capable of growing equally well in sterile broth contained in both straight-neck and swan-neck flasks.	
E)	The first cells must have come from chemical reactions occurring in early Earth.	

49.	Which of the following statements regarding "nonliving" matter is TRUE?	
A)	Nonliving matter would contain the same amount of silicon as living matter.	
B)	Nonliving matter is composed of unique elements never found in living organisms.	
C)	Nonliving matter can change over time (i.e., rocks can weather), and thus can evolve.	
D)	Nonliving matter contains a high percentage of carbon.	
E)	None of the statements regarding nonliving matter is true.	

50.	Given the high degree of "order" living organisms demonstrate, the second law of thermodynamics can never be applied to life.	
A)	True	
B)	False	

51.	If you were to analyze the composition of a human body (Fig. 1.5), which of the following elements would you find to be the MOST abundant?	
A)	hydrogen	
B)	carbon	
C)	oxygen	
D)	silicon	
E)	calcium	

52.	As you will learn in a later chapter (Chapter 25), a trophic pyramid depicts the transfer of energy between different organisms (i.e., plants, herbivores, and carnivores).  Based on the first and second laws of thermodynamics, which of the following is likely TRUE of a trophic pyramid?	
A)	An herbivore gains more energy from eating plants compared to a carnivore eating meat.	
B)	A carnivore gains more energy from eating meat compared to an herbivore eating plants.	
C)	Plants harness more energy from the sun compared to an herbivore eating plants.	
D)	An herbivore gains more energy from eating plants compared to the amount plants harness from the sun.	
E)	Plants harness more energy from the sun compared to an herbivore eating plants, and an herbivore gains more energy from eating plants compared to a carnivore eating meat.	

53.	If you were to compare the entropy of a dog to that of a bucket of water, which of the following statement would be TRUE?	
A)	The entropy of the dog would be greater.	
B)	The entropy of the bucket of water would be greater.	
C)	The entropy of the bucket of water and the entropy of the dog would be equal.	

54.	Based on the characteristics of living organisms, which of the following things would NOT be considered "alive"?	
A)	a spayed cat, which is unable to reproduce	
B)	a plant, which is unable to move when the weather changes	
C)	a bacterium, which is a relatively "simple" organism	
D)	plants and bacteria	
E)	None of the other answer options is correct.	

55.	Which of the following statements is TRUE regarding Louis Pasteur?	
A)	His work demonstrated that life can arise spontaneously, without the input of other organisms.	
B)	His work demonstrated that maggots are produced by flies (i.e., higher organisms do not arise spontaneously); however, it did not address microbial life.	
C)	His work using broth and swan-neck flasks demonstrated that microbes are produced by other microbes.	
D)	His work did not support the findings of Francesco Redi, who believed that life could arise spontaneously.	

56.	Imagine that an owl acquires energy by eating a mouse.  What happens to this energy?	
A)	The owl uses a portion of this energy to fly.	
B)	The owl uses a portion of this energy to catch additional prey.	
C)	Some of this energy is released as heat.	
D)	All of these choices are correct.	

57.	Imagine that a researcher claimed to have created a genetically modified plant that produces twice as much energy as it harnesses from its environment.  How could this be possible?	
A)	The researcher has inserted a mutation into the plant's genome that causes twice the amount of ATP to be produced.	
B)	This is not possible because such a plant would violate the second law of thermodynamics.	
C)	The researcher has found a way to decrease the overall entropy of the plant.	
D)	The researcher has inserted genes into the plant's genome that increase the amount of work the plant is capable of performing.	
E)	The researcher has likely doubled the amount of DNA present in the plant's genome.	

58.	When we say that the cell is the fundamental unit of life, we mean that:	
A)	all living things are made up of one or more cells.	
B)	the smallest entity that can be considered living is a cell.	
C)	a single cell can carry out all life processes.	
D)	life doesn't exist in the absence of cells.	
E)	All of the answer options are correct.	

59.	The metabolic pathway that harvests energy molecules from glucose is highly conserved across many different organisms. This observation suggests that in each of these organisms, the pathway:	
A)	obeys the law of the conservation of energy.	
B)	is subject to the first law of thermodynamics.	
C)	is subject to the second law of thermodynamics.	
D)	is very different from each other.	
E)	is the same, or very similar, to each other.	

60.	The three main groups, or domains, of organisms are:	
A)	animals, plants, and fungi.	
B)	animals, plants, and bacteria.	
C)	bacteria, archaea, and eukaryotes.	
D)	bacteria, archaea, and prokaryotes.	
E)	animals, plants, and protists.	

61.	The first cells were:	
A)	eukaryotes.	
B)	prokaryotes.	
C)	multicellular forms.	
D)	viruses.	
E)	None of the other answer options is correct.	

62.	A mutation in _____ results in a change in _____ that sometimes produces a(n) _____ with altered structure and function.	
A)	RNA; DNA; protein	
B)	DNA; RNA; protein	
C)	protein; DNA; RNA	
D)	protein; RNA; DNA	
E)	RNA; protein; DNA	

63.	Which of the following is the BEST description of mutations?	
A)	They arise in order to benefit an organism.	
B)	They arise in order to harm an organism.	
C)	They do not affect an organism.	
D)	They occur randomly.	
E)	All of the answer options are correct.	

64.	The chemical reactions required to sustain life are collectively referred to as a cell's _____.	

65.	The ostrich egg shown in Figure 1.11 is composed of approximately how many cells?	
A)	1	
B)	100	
C)	10,000	
D)	1,000,000	
E)	100,000,000	

66.	Which of the following types of organisms are based on cellular life?	
A)	bacteria	
B)	yeast	
C)	plants	
D)	animals	
E)	All living organisms are based on cells.	

67.	A retrovirus hijacks a cell's machinery to turn its RNA into DNA, which is then inserted into the cell's genome so viral proteins can be made. Does this virus follow the central dogma?	
A)	yes	
B)	no	

68.	A major difference between eukaryotic cells and prokaryotic cells is that:	
A)	eukaryotic cells have a nucleus and prokaryotic cells do not.	
B)	prokaryotic cells have a nucleus and eukaryotic cells do not.	
C)	neither eukaryotic cells nor prokaryotic cells have a nucleus.	
D)	both eukaryotic cells and prokaryotic cells have a nucleus.	

69.	Organisms from all classifications of life are composed of cells.	
A)	True	
B)	False	

70.	Organisms that possess a nucleus are called prokaryotes; organisms that do not possess a nucleus are called eukaryotes.	
A)	True	
B)	False	

71.	There are many different types of bacteria known to be able to grow in a human host, and they are all disease-causing organisms.	
A)	True	
B)	False	

72.	Which one of the following entities does NOT possess the ability to synthesize its own proteins?	
A)	a human cell	
B)	a virus	
C)	a bacterial cell	
D)	a viral particle and a bacterial cell	
E)	a human cell, a virus, and a bacterial cell	

73.	All of the chemical reactions in a cell that are required to sustain life are referred to as _____.	

74.	The language of nucleic acids is converted to the language of amino acids during the process known as _____.	

75.	Prokaryotic cells found in extreme, harsh environments often belong to the domain _____.	

76.	Which one of the following represents the flow of information as described by the central dogma of molecular biology?	
A)	Information in DNA is transcribed into RNA and then translated into protein.	
B)	Information in DNA is translated into RNA and then transcribed into protein.	
C)	Information in protein is translated into RNA and then stored as DNA.	
D)	Information in RNA is transcribed into DNA and then translated into protein.	
E)	Information in DNA is directly translated into protein.	

77.	You have discovered a new species of prokaryote in a deep-sea thermal vent.  Without any further characterization, which one of the following statements could you make about this species with a high degree of certainty?	
A)	These organisms store their genetic information in a compartment called a nucleus.	
B)	Information in DNA is translated into RNA and then transcribed into protein.	
C)	The organisms are from the domain Archaea.	
D)	Information in RNA is transcribed into DNA and then translated into protein.	
E)	None of the statements can be made with certainty.	

78.	In which of the following domains do the cells store their genetic information in a nucleus?	
A)	Eukarya and Archaea	
B)	Eukarya	
C)	Archaea and Bacteria	
D)	Archaea	
E)	Bacteria and Eukarya	

79.	You have learned that mutations can occur in DNA sequences.  Are all mutations deadly?	
A)	Yes, all mutations are deadly.	
B)	No, all mutations are benign.	
C)	No, some mutations can be beneficial.	
D)	No, mutations in DNA have no effect on cellular processes.	
E)	Yes, all mutations in DNA disrupt the central dogma.	

80.	At some point in their life cycle, all cells have a _____, whereas not all cells have a(n) _____.	
A)	plasma membrane; nuclear membrane	
B)	nucleus; cytoplasm	
C)	plasma membrane; RNA or DNA	
D)	nucleus; nuclear membrane	
E)	nucleus; plasma membrane	

81.	A doctor suspects one of his patients has melanoma (a type of cancer).  He takes a very small biopsy—about 2mm—from a suspicious mole.  This biopsy would only contain about 10 cells, and would make subsequent analyses very difficult.	
A)	True	
B)	False	

82.	Imagine that a scientist is able to isolate a single, intact nerve cell from a human cadaver.  How large could this cell be?	
A)	a single micron	
B)	ten microns	
C)	a hundred microns	
D)	a thousand microns	
E)	a meter	

83.	One of your friends is arguing that viruses are "alive."  What information would you provide to convince him that viruses can't be considered alive?	
A)	Viruses cannot carry out metabolic reactions.	
B)	Viruses contain either RNA or DNA.	
C)	Viruses typically have protein coats, which are distinct from plasma membrane.	
D)	Viruses can carry out metabolic reactions, independent of their environment.	
E)	Viruses are much more closely related to archaeons compared to bacteria.	

84.	Santiago Elena and Richard Lenski performed long-term artificial selection experiments with bacteria. Over time, the bacteria evolved an ability to use succinate as a food source. Which of the following is a conclusion of these experiments?	
A)	Evolution can occur in the laboratory.	
B)	Bacteria can evolve over time.	
C)	Bacteria can evolve an improved ability to use succinate.	
D)	Natural selection can occur in the laboratory.	
E)	All of the answer options are correct.	

85.	The phylogenetic tree below represents a phylogeny of different species of butterflies. What is represented by the circled area on the phylogeny?

A)	the most recent speciation event	
B)	the most ancient speciation event	
C)	present-day species	
D)	a common ancestor	
E)	time	

86.	The phylogenetic tree below represents a phylogeny of different species of butterflies. What is represented by the circled area on the phylogeny?

A)	the most recent speciation event	
B)	the appearance of a new mutation	
C)	the appearance of a new genetic variant	
D)	a common ancestor	
E)	a species that must be extinct	

87.	The metabolic pathway that harvests energy molecules from glucose is highly conserved across many different organisms. From this observation, scientists conclude that:	
A)	they arose early in the evolution of life.	
B)	they arose late in the evolution of life.	
C)	they are conserved simply by chance.	
D)	they are nonessential.	
E)	None of the other answer options is correct.	

88.	Transcription is the process by which:	
A)	proteins are synthesized from RNA molecules.	
B)	RNA is synthesized from protein.	
C)	proteins are synthesized from DNA molecules.	
D)	RNA is synthesized from DNA.	
E)	DNA is synthesized from protein.	

89.	Mutations always result in the death of the organism that acquires them.	
A)	True	
B)	False	

90.	Imagine that you are standing in a field and you see a group of butterflies. You notice an individual that looks significantly different from the other butterflies in the population. This difference allows the butterfly to escape predation more efficiently than other butterflies in the population. How might this trait have arisen in the individual?	
A)	There were more predators in the surrounding area, so the butterfly needed the trait in order to escape predation.	
B)	There were more predators in the surrounding area, so the butterflies allowed themselves to be caught to save the faster butterflies in the population.	
C)	There was a random mutation in a gene that led to differences in the ability to escape predation.	
D)	There was a mutation in a gene that led to differences in the ability to attract mates.	

91.	_____ is NOT a domain of life.	
A)	Protists	
B)	Eukarya	
C)	Archaea	
D)	Bacteria	
E)	Protists, Eukarya, Archaea, and Bacteria are all domains of life.	

92.	According to the phylogenetic tree shown in Figure 1.16, the primate MOST closely related to humans is the:

Photo source: AP Photo/Bela Szandelszky	
A)	orangutan.	
B)	lemur.	
C)	gorilla.	
D)	chimpanzee.	
E)	gibbon.	

93.	Imagine you are standing in a field and you see a group of butterflies. You notice that the butterflies are not identical to each other even though they are all from the same species and the same population. Which of the following statements explains the variation you see in the butterflies? (Select all that apply.)	
A)	differences that result from variation in the genetic material among the butterflies	
B)	differences that result from variation in the environment	
C)	differences in the type of food each butterfly consumes	
D)	differences in the temperature in which each butterfly developed	

94.	Imagine you are standing in a field and you see a group of butterflies. You notice an individual that looks significantly different from the other butterflies in the populations: It has much larger wings and can fly faster than the other butterflies. This difference allows the butterfly to escape predation more efficiently than other butterflies in the population. The difference came about because this butterfly spent more time developing in an area of the habitat that is particularly warm and moist than other butterflies did. Do you expect the following generations to be composed of butterflies with larger wings?	
A)	Yes, this represents a genetic mutation that will be passed onto offspring.	
B)	Yes, this trait is advantageous so more butterflies will choose to develop in warm moist areas of the habitat.	
C)	No, this represents nonheritable variation caused by the environment.	
D)	No, this represents heritable variation but this trait does not increase ability to mate so will not be passed to the next generation.	

95.	Why can a Husky survive better than a Chihuahua in colder temperatures?	
A)	Huskies consume a different diet from Chihuahuas.	
B)	Huskies are exposed to cold temperatures when they are young, whereas Chihuahuas are not.	
C)	Huskies are smaller and have shorter fur than Chihuahuas.	
D)	Huskies are genetically different from Chihuahuas.	

96.	MOST of life's diversity is:	
A)	acellular.	
B)	aerobic.	
C)	microbial.	
D)	terrestrial.	
E)	aquatic.	

97.	Which one of the following types of organisms MOST closely resembles the first cells on Earth?	
A)	algae	
B)	bacteria	
C)	fungi	
D)	plants	
E)	animals	

98.	Elena and Lenski's long-term artificial selection experiment with E. coli demonstrates that bacteria can evolve to metabolize:	
A)	lactose.	
B)	glucose.	
C)	citrate.	
D)	nitrogen.	
E)	succinate.	

99.	Translation is the process by which:	
A)	proteins are synthesized from RNA molecules.	
B)	RNA is synthesized from protein.	
C)	proteins are synthesized from DNA molecules.	
D)	RNA is synthesized from DNA.	
E)	DNA is synthesized from protein.	

100.	Most of the diversity of life on this planet comes from microbes.	
A)	True	
B)	False	

101.	_____ can simply be referred to as change over time.	

102.	How many major branches are there on the evolutionary tree of life?	
A)	one	
B)	two	
C)	three	
D)	six	
E)	12	

103.	In a phylogenetic tree, positions indicating a common ancestor are referred to as:	
A)	branches.	
B)	nodes.	
C)	trunks.	
D)	roots.	
E)	limbs.	

104.	Environmental variation can be used to describe why:	
A)	identical twins have different weights.	
B)	leaves on a single tree turn color at different times in the fall.	
C)	one tomato in a carton spoils before the rest.	
D)	grapes in a single bunch have differing sugar content.	
E)	All of these choices are correct.	

105.	Which one of the following statements about evolution is INCORRECT?	
A)	Evolution of bacteria can be demonstrated in a laboratory by selecting for changes in various metabolic processes.	
B)	Evolution led to the branches in the tree of life, but development of the organisms within a single branch has subsequently remained constant.	
C)	Closely related species display a nested pattern of similarity.	
D)	Organisms that are best able to reproduce contribute disproportionately to subsequent generations.	
E)	Evolution is influenced by both genetic and environmental forces.	

106.	Currently, antibiotic-resistant bacteria are a major concern for all of us.  Antibiotic bacteria have arisen through natural selection.	
A)	True	
B)	False	

107.	You may know that, on average, individuals were shorter 400 years ago compared to today.  The fact that modern-day humans are now taller is likely a reflection of:	
A)	environmental variation, as modern-day diets vary drastically from those of a few centuries ago.	
B)	genetic variation, as over time genes conferring increased height may have been selected for in humans.	
C)	neither environmental variation nor genetic variation; height is random in humans.	
D)	both environmental and genetic variation.	

108.	Consider a single orange tree.  All of the seeds in the oranges of that tree would be considered genetically identical, given that the same plant produces them.	
A)	True	
B)	False	

109.	Viruses compose a fourth, distinct branch on the tree of life.	
A)	True	
B)	False	

110.	Imagine that you are looking at the tree of life.  The majority of branches on this diagram would represent which of the following types of organisms?	
A)	mammals	
B)	microbes	
C)	viruses	
D)	plants	
E)	humans	

111.	Consider a phylogenetic tree.  The node at the bottom of the tree (i.e., the "root") would represent which of the following?	
A)	the common ancestor of all organisms included in the tree	
B)	the common ancestor of a subset of the organisms included in the tree	
C)	an organism that is unrelated to all other organisms included in the tree	
D)	an organism that is the common ancestor for organisms not included in the tree	
E)	Nothing; the node serves only as the starting point of the tree.	

112.	Which of the following statements is TRUE regarding bacteria, eukaryotes, and archaea?	
A)	Bacteria and archaeons share a more recent common ancestor compared to archaeons and eukaryotes.	
B)	Bacteria and eukaryotes share a more recent common ancestor compared to archaeons and bacteria.	
C)	Eukaryotes and bacteria share a more recent common ancestor compared to eukaryotes and archaeons.	
D)	Eukaryotes and archaeons share a more recent common ancestor compared to bacteria and eukaryotes.	

113.	Which of the following statements is TRUE regarding the initial work of Santiago Elena and Richard Lenski?	
A)	They demonstrated that populations of bacteria can evolve in culture.	
B)	They demonstrated that an individual bacterium can evolve in culture.	
C)	They demonstrated that bacteria from earlier and later generations behave similarly in succinate-rich culture.	
D)	They demonstrated that mutations in DNA are responsible for the evolution of bacteria in culture.	
E)	They demonstrated that evolution cannot occur in cultured bacteria.	

114.	Why are bacteria a useful model in which to study evolution?	
A)	Bacteria can produce large populations on a very small growth area.	
B)	Bacteria have a short generation time.	
C)	Spontaneous mutations can arise in bacteria populations.	
D)	Bacteria can be grown rather easily in certain culture media.	
E)	All of these statements are reasons why bacteria are useful model organisms to study evolution.	

115.	Imagine walking through a tropical rainforest. You notice that there are different types of trees, birds, insects, and a plethora of other living things. A few weeks later you are taking a walk through the desert and notice that the trees, birds, insects, and many other living things are different than those you saw in the rainforest. Which of the following statements BEST explains the differences between each of these ecological systems?	
A)	The manner in which organisms interact with each other and their physical environment shapes the diversity found in an ecological system.	
B)	Organisms that evolved in the rainforest found it easier to live in that ecological system, so they have not spread out to evolve adaptations necessary to live in the desert.	
C)	Organisms in each ecological system haven't had enough time to evolve the adaptations for the other ecosystem; with enough time they will evolve into the other ecological system.	
D)	Organisms in each ecological system are there by chance and their presence in different ecological systems does not have a biological explanation.	

116.	Interactions between organisms lead to the evolution of particular traits in populations of those organisms over time.	
A)	True	
B)	False	

117.	Variation among individuals in a species is usually caused by:	
A)	environmental variation.	
B)	genetic variation.	
C)	infectious variation.	
D)	both environmental and genetic variation.	
E)	environmental, genetic, and infectious variation.	

118.	Trees in the desert and trees in the rainforest experience vast differences in the amount of water available for uptake. Water can be lost from the leaf surface very easily in dry and hot regions. What types of differences might you expect between different tree species in a rainforest compared with a desert?	
A)	Rainforest trees have adaptations for conserving water.	
B)	Rainforest trees have adaptations for requiring less water than trees in the desert.	
C)	Rainforest trees do not have any adaptations related to water conservation or loss.	
D)	Rainforest trees have different adaptations for water conservation and loss than trees in the desert.	

119.	Ecological relationships reflect the _____ traits of organisms in nature.	
A)	behavioral	
B)	physiological	
C)	biomechanical	
D)	behavioral and physiological	
E)	behavioral, physiological, and biomechanical	

120.	The effect of increasing human populations can be seen in many different ways. Which of the following describes how human actions have caused evolutionary changes in different organisms? (Select all that apply.)	
A)	Increased use of antibiotics has caused many bacterial strains to become resistant.	
B)	Planting different commercial crops has increased their worldwide distribution.	
C)	Overhunting of the dodo caused its extinction.	
D)	Forests were cut down to acquire lumber for construction	

121.	Which one of the following statements about viruses is INCORRECT?	
A)	Most viruses use cellular machinery to replicate their genetic material.	
B)	The genomes of viruses are enclosed in a protein coat and occasionally a lipid bilayer envelope.	
C)	Viruses possess the ability to harness energy from the environment.	
D)	Viruses are valuable tools in biological research.	
E)	Some types of viruses integrate their genomes into the genome of the host organism.	

122.	Some plants are dependent on animals for:	
A)	pollination.	
B)	seed dispersion.	
C)	respiration.	
D)	pollination and seed dispersion.	
E)	pollination, seed dispersion, and respiration.	

123.	Biology can be approached by studying:	
A)	cognition.	
B)	physiology.	
C)	biomechanics.	
D)	behavior.	
E)	cognition, physiology, biomechanics, and behavior are all ways in which biology can be approached.	

124.	The study of how organisms interact with each other and with their physical environment in nature is called:	
A)	ecology.	
B)	metabolism.	
C)	evolution.	
D)	entropy.	

125.	Imagine walking through a tropical rainforest. You notice that there are different types of trees, birds, insects, and other organisms. A few weeks later you are taking a walk through the desert and notice that the trees, birds, insects, and other organisms are different than those you saw in the rainforest. Which of the following statements BEST explains the differences between each of these ecological systems?	
A)	Organisms in each ecological system have short dispersal distances and are confined to the area where they mate.	
B)	Organisms in each ecological system have evolved in that system and have adaptations suited for that environment.	
C)	Organisms in each ecological system haven't had enough time to evolve the adaptations for the other ecosystem; with enough time they will evolve into the other ecological system.	
D)	Organisms in each ecological system are there by chance and their presence in different ecological systems does not have a biological explanation.	

126.	The study of how organisms interact with each other and with their physical environment is referred to as _____.	

127.	Which one of the following is NOT required for a plant to grow and reproduce?	
A)	hydrogen peroxide	
B)	carbon dioxide	
C)	water	
D)	light	
E)	basic nutrients	

128.	Consider the following two statements, and determine which one is TRUE:
1.   Animal behavior can be required for the reproductive success of plants.
2.   Animal behavior can be detrimental to the reproductive success of plants.	
A)	Statements 1 and 2 are both true.	
B)	Statements 1 and 2 are both false.	
C)	Statement 1 is true; statement 2 is false.	
D)	Statement 1 is false; statement 2 is true.	

129.	Which one of the following species-species interactions is MOST likely to be mutually beneficial?	
A)	human and yeast	
B)	leaf-cutter ant and tropical plant	
C)	two plant species sharing the same resources	
D)	honeybee and apple flower	
E)	All of these choices are correct.	

130.	If plants never relied on insects, birds, or bats to serve as pollinators, which of the following would likely STILL have developed?	
A)	nectar	
B)	fruits	
C)	scented flowers	
D)	colored flowers	
E)	All of these choices are correct.	

131.	Imagine that you are comparing the teeth of a wolf to those of an elephant.  As you probably know, a wolf's teeth are sharp, whereas an elephant's teeth are flatter and broader.  Different tooth shapes likely evolved to meet organisms' different dietary requirements.	
A)	True	
B)	False	

132.	A researcher carries out an experiment during the summertime in New England.  He plants cacti on two adjacent pieces of land that are identical, except for the fact that one piece of land has been cleared of all other vegetation.  He notices that cacti planted on the cleared land take root and grow, whereas those planted on the uncleared land don't.  What is a likely explanation?	
A)	By clearing one piece of land and disturbing the soil, the researcher has recapitulated the sandy environment where cacti typically grow.	
B)	Microorganisms in the soil of the cleared land likely infect cacti roots.	
C)	Animals have easier access to cacti in the uncleared land.	
D)	Other plants likely compete with cacti for resources on the uncleared land.	
E)	All of these choices are correct.	

133.	Given that people typically don't eat fruit seeds, humans play only a minor role in plant dispersal.	
A)	True	
B)	False	

134.	Through interactions with insects, birds, and other organisms, plants have evolved which of the following?	
A)	nectar	
B)	fruit	
C)	colored flowers	
D)	scented flowers	
E)	All of these choices are correct.	

135.	A tourist is admiring the diversity of plant and animal life in the Amazon rainforest.  This diversity is the result of which of the following?	
A)	the interactions between plants and herbivores	
B)	the interactions between herbivores and carnivores	
C)	the interactions between plants of different species	
D)	the interactions between plants of the same species	
E)	All of these choices are correct.	

136.	If you have ever drunk tea, you may have noticed that it can provide a "caffeine kick."  Why might tea plants have evolved to produce caffeine in their leaves?	
A)	Caffeine positively affects the nervous system of herbivores, encouraging predation.	
B)	Caffeine adversely affects the nervous system of herbivores, discouraging predation.	
C)	Caffeine is an attractant to insects, and encourages insects to live on tea plant leaves.	
D)	Caffeine is produced by tea plants to attract pollinators, and serves the same function as nectar.	
E)	Caffeine is an attractant to both insects and pollinators.	

137.	Which of the following statements regarding plants is TRUE?	
A)	Plants do not reproduce sexually.	
B)	Plants only produce nectar for the benefit of insects.	
C)	Plants evolved independently of other organisms.	
D)	Unlike animal life, plant life does not require carbon.	
E)	None of these statements regarding plants is true.	

138.	Which of the following types of scientists would specifically study the interactions between flies, frogs, fish, and water lilies in a pond?	
A)	a botanist	
B)	a geneticist	
C)	an ecologist	
D)	a neurobiologist	
E)	a zoologist	

139.	Which of the following things would constitute the ecological system of a forest?	
A)	the microbes in the soil of the forest	
B)	the dead leaves blanketing the forest floor	
C)	rocks located on the forest floor	
D)	the birds inhabiting the trees of the forest	
E)	All of these contribute to the ecological system of a forest.	

140.	G. Evelyn Hutchinson described evolution as which of the following?	
A)	a play	
B)	a stage	
C)	an actor	
D)	a curtain	
E)	a stagelight	

141.	The figure below shows projected changes in distributions of beech trees and chinquapin oak trees in Japan if human activities continue to cause global temperatures to rise. 

Data from: Dr. Masahiro Amano, unpublished paper.

Which of the following statements accurately reflects these predictions?	
A)	The area where beech and chinquapin oak are found together will stay the same.	
B)	Beech distribution will increase to the south of its present-day distribution.	
C)	Chinquapin oak distribution will increase with rising temperatures.	
D)	Beech trees will become extinct.	

142.	Which one of the following statements about the human impact on Earth's ecology is CORRECT?	
A)	Agriculture has increased abundance and distribution of some species, while decreasing abundance and distribution of other species.	
B)	Humans commandeer as much as 25 percent of all photosynthetic production on land.	
C)	More atmospheric nitrogen is converted to ammonia by humans than by the rest of nature.	
D)	Human activities produce more carbon dioxide than do volcanoes.	
E)	All of these statements about the human impact on Earth's ecology are correct.	

143.	Humans have affected different organismal populations in which of the following ways? (Select all that apply.)	
A)	habitat destruction	
B)	poaching	
C)	agriculture	
D)	overfishing	

144.	If the duration of life on Earth was on a scale of 20,000 days, for how many of those days would the human species be present?	
A)	1	
B)	100	
C)	2000	
D)	10,000	
E)	20,000	

145.	Which one of the following organisms has been MOST damaged by the influence of humans?	
A)	rats	
B)	corn	
C)	cockroaches	
D)	apples	
E)	white rhinos	

146.	Humans have affected life on Earth in which of the following ways?	
A)	Many species have been driven to extinction.	
B)	Some species have actually benefited from human activities.	
C)	We have altered or destroyed the habitat of many species.	
D)	We are contributing to the carbon, nitrogen, and other biogeochemical cycles.	
E)	All of the answer options are ways humans are affecting life on Earth.	

147.	Humans have a negative impact on all species with which they interact.	
A)	True	
B)	False	

148.	Biology is more completely understood using an integrated approach as opposed to a compartmentalized approach.	
A)	True	
B)	False	

149.	Which one of the following species is endangered by human activity, but not yet extinct?	
A)	the dodo	
B)	the dusky seaside sparrow	
C)	the African white rhinoceros	
D)	the carrier pigeon	
E)	the Bali tiger	

150.	With humans making up such a small percentage of life on Earth, which of the following represents the rationale behind spending a disproportionate amount of scientific research studying humans?	
A)	Humans are interested in learning how their own bodies function.	
B)	Our role in the ecosystem needs to be understood in order to plan for our future.	
C)	The more that is discovered about humans, the more likely it is that disease can be combatted.	
D)	Humans are curious about their origins.	
E)	All of the above are reasons for spending a disproportionate amount of scientific research studying humans.	

151.	Human activities have likely aided in the dispersal—and success—of which of the following organisms?	
A)	wheat	
B)	bed bugs	
C)	chickens	
D)	corn	
E)	All of these choices are correct.	

152.	Human activities have endangered—or caused the extinction of—which of the following organisms?	
A)	dodos	
B)	white rhinoceros	
C)	passenger pigeons	
D)	Bali tigers	
E)	All of these choices are correct.	

153.	Recall that humans have drastically increased the amount of ammonia (NH3) that is generated from nitrogen gas (N2), and NH3 can be utilized by organisms to build organic compounds.  What may be a result of excess human-produced NH3?	
A)	With NH3-based fertilizers, humans can increase crop yields.	
B)	Excess NH3-based fertilizers can accumulate in lakes and rivers, disrupting aquatic habitats.	
C)	Excess NH3-based fertilizers can cause an overgrowth of plants and algae in bodies of water.	
D)	All of these choices are correct.	

154.	Human activities have had a dramatic effect on Earth's climate and landscape for the majority of Earth's history.	
A)	True	
B)	False	

155.	A researcher notices that the migration patterns of butterflies have changed over the last several decades, with butterflies migrating earlier in the season and over shorter distances.  What are possible explanations for this observation?	
A)	Through agricultural practices, humans have altered the geographic range of the butterflies' food sources (i.e., certain flowers).	
B)	Through agricultural practices, humans have altered the geographic range of the butterflies' predators (i.e., birds).	
C)	Humans have increased Earth's temperature by releasing CO2 into the atmosphere, altering the flowering times of the butterflies' food sources.	
D)	Through agricultural practices, humans have introduced additional food sources for the butterflies.	
E)	All of these choices are correct.	

156.	Which of the following could have prevented the bubonic plague in Europe?	
A)	increased crop yields	
B)	antimalarial drugs	
C)	antibiotics	
D)	the use of fertilizer	
E)	All of these choices are correct.	

157.	Scientists can FULLY understand how viruses infect humans by studying the interactions between nonhuman cells and viruses.	
A)	True	
B)	False	

158.	If humans never existed on Earth, which of the following animals would likely NOT be found?	
A)	German shepherd dogs	
B)	Siamese cats	
C)	Clydesdale horses	
D)	All of these choices are correct.	

159.	If humans never existed on Earth, which of the following organisms would likely still be found?	
A)	cockroaches	
B)	wheat	
C)	passenger pigeons	
D)	rats	
E)	All of these choices are correct.	

160.	Scientists have been able to improve human health by studying which of the following?	
A)	the chemicals contained within the bark of certain tree species	
B)	the compounds produced by molds that can function as antibiotics	
C)	the compounds produced by bacteria that can function as antibiotics	
D)	the venom of snakes that can be used to generate antivenom	
E)	All of these choices are correct.	

161.	Which of the following events was the deadliest in terms of the proportion of the Earth's total population that it affected?	
A)	World War I	
B)	the volcanic eruption at Pompeii	
C)	the bubonic plague	
D)	the sinking of the Titanic	
E)	the Trojan War	

Answer Key

1.	B	
2.	E	
3.	C	
4.	D	
5.	B	
6.	B	
7.	A	
8.	B	
9.	C	
10.	D	
11.	D	
12.	A	
13.	A	
14.	C	
15.	A	
16.	B	
17.	C	
18.	E	
19.	A	
20.	experiment	
21.	theory	
22.	B	
23.	C	
24.	D	
25.	A	
26.	D	
27.	B	
28.	A	
29.	D	
30.	E	
31.	B	
32.	A	
33.	B	
34.	C	
35.	B	
36.	E	
37.	B	
38.	A	
39.	B	
40.	C	
41.	D	
42.	A	
43.	B	
44.	B	
45.	E	
46.	disorder	
47.	D	
48.	C	
49.	E	
50.	B	
51.	C	
52.	E	
53.	B	
54.	E	
55.	C	
56.	D	
57.	B	
58.	E	
59.	E	
60.	C	
61.	B	
62.	B	
63.	D	
64.	metabolism	
65.	A	
66.	E	
67.	B	
68.	A	
69.	A	
70.	B	
71.	B	
72.	B	
73.	metabolism	
74.	translation	
75.	Archaea	
76.	A	
77.	E	
78.	B	
79.	C	
80.	A	
81.	B	
82.	E	
83.	A	
84.	E	
85.	D	
86.	D	
87.	A	
88.	D	
89.	B	
90.	C	
91.	A	
92.	D	
93.	A, B, C, D	
94.	C	
95.	D	
96.	C	
97.	B	
98.	E	
99.	A	
100.	A	
101.	Evolution	
102.	C	
103.	B	
104.	E	
105.	B	
106.	A	
107.	D	
108.	B	
109.	B	
110.	B	
111.	A	
112.	D	
113.	A	
114.	E	
115.	A	
116.	A	
117.	D	
118.	D	
119.	E	
120.	A, B, C, D	
121.	C	
122.	D	
123.	E	
124.	A	
125.	B	
126.	ecology	
127.	A	
128.	A	
129.	D	
130.	B	
131.	A	
132.	D	
133.	B	
134.	E	
135.	E	
136.	B	
137.	E	
138.	C	
139.	E	
140.	A	
141.	C	
142.	E	
143.	A, B, C, D	
144.	A	
145.	E	
146.	E	
147.	B	
148.	A	
149.	C	
150.	E	
151.	E	
152.	E	
153.	D	
154.	B	
155.	E	
156.	C	
157.	B	
158.	D	
159.	E	
160.	E	
161.	C