1.	Which of the following is classified as a living organism by biologists?	
A)	DNA molecule	
B)	Bacterium	
C)	Metabolic energy	
D)	Feather	
E)	Meteorite	

2.	One reason we consider the dormant seed of a desert plant to be alive is that it	
A)	is extracting energy from the environment.	
B)	formed within a nonliving structure.	
C)	is evolving.	
D)	contains genetic material.	
E)	is always converting molecules into new biological molecules.	

3.	One reason biologists consider viruses to be a part of life is that viruses	
A)	are composed of cells.	
B)	evolve.	
C)	live independently.	
D)	carry out physiological functions, independently of cells.	
E)	extract energy from the environment.	

4.	Suppose you were leading a team looking for extraterrestrial life on distant planets. You find something that you suspect might be a living organism. Which characteristic would be a requirement in order for it to be classified as a living organism?	
A)	Ability to self-replicate	
B)	Genetic material in the form of DNA	
C)	Cellular structure that includes a nucleus	
D)	Ability to transform energy from the sun through photosynthesis	
E)	Aerobic metabolism	

5.	The abundance of O2 led to the evolution of	
A)	anaerobic eukaryotes.	
B)	aerobic eukaryotes.	
C)	anaerobic prokaryotes.	
D)	aerobic prokaryotes.	
E)	Both b and d	

6.	The Curiosity rover is currently searching for signs of life on Mars. What kind of evidence would most likely indicate the presence of living organisms on Mars?	
A)	Fossilized prokaryotic cells	
B)	Different nucleic acids and amino acids than those found on Earth	
C)	Fatty acid molecules	
D)	Complex molecules containing genetic information	
E)	Simple organic molecules	

7.	Evidence indicates that all life on Earth today	
A)	has a single common ancestor.	
B)	requires oxygen for life.	
C)	is able to extract energy from the sun.	
D)	evolved from ancestors containing genetic material in the form of proteins.	
E)	is multicellular.	

8.	If we picture the history of Earth as a 30-day month, modern humans arose	
A)	at the beginning of week 4.	
B)	on day 27.	
C)	in the last 5 minutes of day 30.	
D)	on day 15.	
E)	in the early morning of day 30.	

9.	Earth is approximately _______ years old.	
A)	2–3 thousand	
B)	4–5 million	
C)	40–50 million	
D)	4–5 billion	
E)	5 trillion	

10.	Which of the following is the most probable order of appearance of molecules and structures that led to the evolution of life on Earth?	
A)	Nucleic acids, proteins, membranes, cells	
B)	Proteins, membranes, nucleic acids, cells	
C)	Membranes, nucleic acids, proteins, cells	
D)	Cells, membranes, nucleic acids, proteins	
E)	Proteins, cells, nucleic acids, membranes	

11.	What is one major reason that the earliest organisms on Earth were confined to the oceans?	
A)	The oxygen in the atmosphere was toxic.	
B)	There was not enough oxygen in the atmosphere to support life.	
C)	Not enough ultraviolet light could penetrate the atmosphere to support life.	
D)	The oceans created a shield against the damaging effects of ultraviolet radiation.	
E)	The salt within the oceans provided the raw materials for making proteins.	

12.	If you were able to travel back in time 4 billion years to when life first appeared on Earth, what feature of Earth would make it immediately impossible for you to survive?	
A)	The high ozone content of the air would interfere with metabolic processes.	
B)	There would be no water on Earth.	
C)	There would not be enough ultraviolet radiation to support photosynthesis.	
D)	There would not be any protein-containing organisms for food.	
E)	The oxygen content of the air would be too low to support aerobic metabolism.	

13.	What is the correct order in which the following appeared during the early evolution of life on Earth?	
A)	Oxygen, ozone, photosynthesis, life on land	
B)	Photosynthesis, oxygen, ozone, life on land	
C)	Life on land, photosynthesis, oxygen, ozone	
D)	Ozone, oxygen, photosynthesis, life on land	
E)	Oxygen, photosynthesis, life on land, ozone	

14.	A prerequisite for the survival of life on land was the accumulation of a protective layer of	
A)	O2 in the atmosphere.	
B)	CO2 in the atmosphere.	
C)	water vapor in the atmosphere.	
D)	ozone in the atmosphere.	
E)	bacteria in the soil.	

15.	The chemical formula for molecular oxygen is	
A)	O.	
B)	O2.	
C)	H2O2.	
D)	O3.	
E)	CO2.	

16.	Ozone is important to life on Earth because it	
A)	is used for aerobic metabolism.	
B)	can be used in place of oxygen.	
C)	helps block ultraviolet radiation.	
D)	provides energy to some basic forms of life.	
E)	sits in the lower atmosphere as a protective layer.	

17.	For a multicellular organism to have evolved from a unicellular ancestor, what new feature must have been present that was not necessary for unicellular life-forms?	
A)	A mechanism for cell division	
B)	Adhesion molecules on the surfaces of the cells	
C)	Specialization of cellular functions	
D)	Chloroplasts	
E)	A mechanism for cell movement	

18.	Every living organism on Earth can be assigned to one of three separate	
A)	species.	
B)	genus groups.	
C)	domains.	
D)	ancestors.	
E)	genomes.	

19.	Which structure(s) is/are necessary in the forming of a cell?	
A)	Nucleus	
B)	Organelles	
C)	Membrane	
D)	Chloroplast	
E)	Mitochondria	

20.	Scientists estimate that for more than _______ years after cells originated, all organisms consisted of one cell.	
A)	250,000	
B)	2 million	
C)	200 million	
D)	2 billion	
E)	20 billion	

21.	Which process would be most effective at preventing evolutionary change in a population of bacteria?	
A)	Imperfect replication of genetic material	
B)	Formation of spontaneous mutations	
C)	Cell division	
D)	Perfectly accurate copying of DNA	
E)	Production of functional proteins	

22.	If you were trying to create rapid evolutionary change in a population of bacteria, what treatment would be most effective?	
A)	Exposing the bacteria to UV light, which damages DNA	
B)	Growing the bacteria under optimal conditions for growth	
C)	Maintaining the bacteria at 4°C, which slows growth	
D)	Freezing the bacteria in liquid nitrogen	
E)	There is no treatment that could induce evolutionary change.	

23.	It is hypothesized that mitochondria in eukaryotic cells evolved by endosymbiosis, when a larger cell ingested a smaller cell. If you were examining eukaryotic cells using a high-powered microscope, what evidence would you look for that would best support this hypothesis?	
A)	Nuclei within the mitochondria	
B)	Chloroplasts within the mitochondria	
C)	Two membranes around each mitochondrion	
D)	A rupture in the membrane of the cell	
E)	A second cell within each mitochondrion	

24.	The initial accumulation of oxygen in the atmosphere was the result of photosynthesis from an organism most like modern	
A)	algae.	
B)	mosses.	
C)	kelp.	
D)	eukaryotes.	
E)	cyanobacteria.	

25.	Cells	
A)	are composed of many types of tissues.	
B)	are found in plants and animals, but not bacteria.	
C)	are the smallest entity studied by biologists.	
D)	can be building blocks for complex organisms.	
E)	must contain DNA within a nucleus.	

Use the following to answer questions 26-29:

Refer to the figure below showing a tree of life.

26.	What is one conclusion that you can draw from the figure?	
A)	Plants are more closely related to Archaea than they are to animals.	
B)	Animals are more closely related to fungi than they are to plants.	
C)	Animals and plants belong to different domains.	
D)	Chloroplasts are found only in plants.	
E)	Chloroplasts evolved before mitochondria.	

27.	From the figure you can conclude that plants evolved from	
A)	protists.	
B)	endosymbiotic bacteria.	
C)	mitochondria.	
D)	Bacteria.	
E)	Archaea.	

28.	If the estimates on the figure are accurate, then you can conclude that	
A)	more animal species exist than species of plants or fungi.	
B)	most Archaea species have been described.	
C)	more species of fungi exist than species of animals.	
D)	fewer species remain to be described than have already been described.	
E)	there are more species of protists than any other group.	

29.	Which statement concerning the figure is true?	
A)	All protists are more closely related to other protists than they are to other organisms.	
B)	Only one domain includes single-celled prokaryotes.	
C)	Two of the domains had endosymbiotic events leading to the formation of mitochondria and chloroplasts.	
D)	All three domains split from a common ancestor.	
E)	Two of the domains include multicellular organisms.	

30.	A phylogenetic tree	
A)	classifies all plant species based on their habitats.	
B)	diagrams the evolutionary history of a particular group of organisms.	
C)	is based on binomial nomenclature.	
D)	only catalogs fossil plants.	
E)	only uses genome sequencing data.	

31.	Plants are _______ organisms that are _______ of oxygen production.	
A)	eukaryotic unicellular; capable	
B)	eukaryotic multicellular; incapable	
C)	prokaryotic multicellular; capable	
D)	prokaryotic unicellular; incapable	
E)	eukaryotic multicellular; capable	

32.	Biologists have organized the diversity of life into three domains based largely on	
A)	physical similarities.	
B)	ecological niches.	
C)	chronological order.	
D)	molecular data.	
E)	numbers of species.	

33.	While going through a museum, you see the fossilized skeletons of the organisms listed below. Which one is a member of the genus that is our closest relative?	
A)	Chimpanzee (Pan troglodytes)	
B)	Neanderthal (Homo neaderthalensis)	
C)	Lucy, a member of Australopithecus afarensis	
D)	Gorilla (Gorilla gorilla)	
E)	Gibbon (Hylobates lar)	

34.	Which of the scientific names below is written correctly?	
A)	homo sapiens	
B)	Branta Canadensis	
C)	Roundworm	
D)	Neanderthalensis homo	
E)	Canis lupis	

35.	In looking at prepared slides of organisms from pond water using a microscope, you see a unicellular organism that has genetic material but no nucleus. Which group could this organism possibly belong to?	
A)	Bacteria	
B)	Plants	
C)	Fungi	
D)	Animals	
E)	Protists	

36.	A phylogenetic tree	
A)	shows evolutionary relationships.	
B)	relies for its construction on evidence from fossils, metabolic processes, and molecular analyses of genomes.	
C)	helps us understand the history and relationships of living organisms.	
D)	shows the order in which populations split and evolved into new species.	
E)	All of the above	

37.	By studying yeasts, we can discover facts about human cells because yeasts and humans	
A)	are both prokaryotes.	
B)	use the same genetic code.	
C)	contain the same genome.	
D)	use chloroplasts to make sugars.	
E)	share a common viral ancestor.	

38.	Which list represents a correct ordering of the levels of complexity at which life is studied, from most simple to most complex?	
A)	Community, population, organism, organ, tissue, cell	
B)	Cell, organ, tissue, organism, population, community	
C)	Cell, tissue, organ, organism, population, community	
D)	Cell, tissue, organ, population, organism, community	
E)	Tissue, organ, cell, population, organism, community	

Use the following to answer questions 39-40:

Refer to the figure below.

39.	In the image above, what is the largest (highest) level of biological organization that is visible?	
A)	Community	
B)	Organism	
C)	Landscape	
D)	Biosphere	
E)	Population	

40.	In the image above, what is the smallest (lowest) level of biological organization that is visible?	
A)	Community	
B)	Organism	
C)	Molecule	
D)	Cell	
E)	Population	

41.	The cells in your body	
A)	are static once your body reaches maturity.	
B)	replace molecules throughout your life.	
C)	use energy when you are awake but not when you are asleep.	
D)	break down and rebuild proteins slowly over a matter of years.	
E)	release hydrogen from food and combine it with water to create carbon dioxide.	

42.	Refer to the figure below showing a community containing voles, grass, owls, and foxes. In this community, interactions determine the number of voles. What would initially happen to this community if foxes were removed?

A)	The number of owls would diminish.	
B)	The number of voles would diminish.	
C)	The abundance of grass would increase.	
D)	The community would collapse.	
E)	The number of voles would increase.	

43.	A systems analysis approach to understanding how biological systems function is used to	
A)	predict how a complicated metabolic network will change over time.	
B)	analyze the fossil record.	
C)	indicate phylogenetic relationships.	
D)	determine the age of Earth.	
E)	examine organelles within a cell.	

44.	Your body constitutes a system of organized units controlling your internal environment, such as the concentration of Na+ in your blood. If this concentration falls below normal, you would have hyponatremia, a condition that can cause headaches, mental confusion, and even seizures. Which event would most likely cause hyponatremia?	
A)	Gut cells absorbing too much Na+ from food	
B)	Kidney cells absorbing too much Na+ from urine	
C)	Sweating profusely, followed by drinking large quantities of water	
D)	Producing increased amounts of urine after drinking several cups of coffee	
E)	Kidney cells excreting Na+ into the urine	

45.	During childbirth, the hormone oxytocin causes uterine contractions. These contractions move the baby toward the birth canal (vagina), where it pushes on pressure-sensing receptors. These receptors signal the mother's hypothalamus to produce more oxytocin, which in turn increases the uterine contractions. This is an example of	
A)	gene regulation.	
B)	positive feedback.	
C)	a cellular-level system.	
D)	a computational model.	
E)	negative feedback.	

46.	Genes are	
A)	nucleotides that code for DNA.	
B)	segments of proteins.	
C)	sequences of DNA that code for proteins.	
D)	static and do not change over time.	
E)	each made up of billions of nucleotides.	

47.	Mutations	
A)	occur in proteins.	
B)	are alterations in an organism's DNA.	
C)	are not caused by chemicals.	
D)	usually improve the function of the organism.	
E)	are not passed on from one generation to the next.	

48.	If a mutation arises spontaneously in one of your blood cells,	
A)	you can pass that mutation on to your offspring.	
B)	it would most likely improve the function of that blood cell.	
C)	the blood cell is evolving.	
D)	it could have been caused by exposure to radiation.	
E)	it will be passed on to all the other cells in your body.	

49.	Which trait or function is the same in muscle cells and brain cells?	
A)	Cell function	
B)	Extracellular environment	
C)	Expressed genes	
D)	Genome	
E)	Proteins formed	

50.	The sequencing of the human genome	
A)	started at the beginning of 2001, but has not yet been completed.	
B)	is not possible, because the human genome is too large.	
C)	involved figuring out the order of approximately 1000 nucleotides.	
D)	revealed that humans have fewer genes than expected.	
E)	will allow us to compare the human genome with that of other primates but not other organisms such as roundworms.	

51.	Evolution is the change in the genetic makeup of	
A)	cells within an organism.	
B)	organs within an organism.	
C)	populations of organisms over time.	
D)	fossils from the distant past.	
E)	future organisms within the biosphere.	

52.	In formulating his theory of evolution, Darwin used information available to him through observation and common knowledge, including the knowledge that	
A)	offspring differ from their parents and that populations of species display variation.	
B)	genes are the basis for inheritance and that mutations in DNA lead to evolutionary change.	
C)	populations do not change over time, though individuals within a population do.	
D)	the fossil record includes all forms of present day life.	
E)	cells pass on their genetic material through cell division and all cells within an organism have the same genome.	

53.	Darwin noted that all populations have _______ potential to grow, but in nature most populations _______ over time.	
A)	limited; are stable	
B)	unlimited; grow slowly	
C)	limited; fluctuate unpredictably	
D)	unlimited; do not have unchecked growth	
E)	limited; decrease in growth	

54.	Natural selection acts	
A)	by causing mutations in the genome.	
B)	by producing structural and functional changes within organisms.	
C)	through differential probabilities of survival and reproductive success.	
D)	through the selection of breeding pairs that produce offspring with specialized characteristics.	
E)	by allowing unlimited growth of populations.	

55.	Darwin referred to the differential reproductive success of individuals with particular variations as	
A)	evolution.	
B)	artificial selection.	
C)	the cell theory.	
D)	natural selection.	
E)	the inheritance of acquired characteristics.	

56.	Which of the following is one of the key points in Darwin's explanation of evolution?	
A)	The biological structures most likely to be inherited are those that have become best suited to the environment through constant use.	
B)	All mutations that occur are those that will help future generations fit more successfully into their environments.	
C)	Any trait that confers even a small increase in the probability that its possessor will survive and reproduce will be strongly favored and will spread through the population.	
D)	Genes change in order to help organisms cope with problems encountered within their environments.	
E)	Extinction is nature's way of weeding out undeserving organisms.	

57.	The toe pads of tree frogs and the spines of cacti are examples of	
A)	behavioral traits.	
B)	structural adaptations.	
C)	sexually selected traits.	
D)	artificially selected traits..	
E)	proximate explanations.	

58.	Which statement about evolution is true?	
A)	The diversity of life depends on the existence of similar environments and ecological communities throughout the globe.	
B)	Sexual selection contributes to the diversity of life.	
C)	Earth has existed and changed over a few thousand years, at most.	
D)	All ancestral forms of life were very similar to organisms that currently exist.	
E)	Some organisms that exist do not share common ancestors with other organisms.	

59.	Evolutionary theory is a	
A)	hypothesis based on theories.	
B)	historical model showing how organisms changed in the ancient past.	
C)	body of facts that allows us to make predictions.	
D)	useful tool for long-term predictions, but it is not useful for short-term predictions.	
E)	set of mechanisms that explains exactly how biological populations change over time.	

60.	A scientist walking by a pristine stream, and then a polluted pond below a mill, observes that fish are present in the stream but not in the pond. The scientist then says, “polluted water kills fish.” This statement is an example of	
A)	an evaluation of experiment results.	
B)	scientific inquiry.	
C)	quantifiable data.	
D)	a hypothesis.	
E)	a fact.	

61.	The main purpose of any single experiment is to	
A)	obtain accurate quantitative measurements.	
B)	prove unambiguously that a particular hypothesis is correct.	
C)	avoid a merely comparative analysis.	
D)	answer as many key questions as possible.	
E)	test a prediction that is based on a hypothesis.	

62.	In scientific methodology, a hypothesis is	
A)	formed before any observations are made.	
B)	a guess that cannot be tested.	
C)	a tentative answer to a question that can be tested.	
D)	formed after an experiment has been designed.	
E)	a set of data obtained from an experiment.	

63.	Which statement about the scientific method is true?	
A)	After forming a hypothesis, scientists apply logic to make predictions from the hypothesis.	
B)	The most informative experiments are those that have the ability to show that a hypothesis is correct.	
C)	In a comparative experiment, a scientist compares groups that differ in terms of a variable that has been manipulated in one of the groups and left unaltered in the other group.	
D)	Controlled experiments are valuable when we do not know or cannot control the critical variables.	
E)	A statistical test of a hypothesis starts with the premise that a significant difference exists between the groups in the study.	

64.	Which of the following can result from a scientific investigation?	
A)	Refinement of the experimental design	
B)	Formulation of new questions that result in additional experimentation	
C)	Use of statistical tests to evaluate the significance of the results	
D)	Experiments that will be repeated and verified by later experiments	
E)	All of the above	

65.	Which statement about the experiments of Tyrone Hayes on abnormalities of male frog sex organs is correct?	
A)	In a set of controlled experiments, Hayes had to reject his hypothesis that atrazine was causing abnormalities in male frogs.	
B)	As a result of the comparative experiments, Hayes formed a new hypothesis that snails were causing the limb deformities in the frogs.	
C)	The controlled experiments compared the effects of various atrazine concentrations on reproductive tissues.	
D)	Hayes reasoned that if atrazine caused abnormal testes development, then all testes abnormalities in tadpoles are caused by various concentrations of atrazine.	
E)	The experiments showed that the abnormality rate was proportional to the level of atrazine exposure.	

66.	Despite numerous studies showing the negative effects of atrazine on frog development, the Environmental Protection Agency continues to allow restricted use of atrazine as long as environmental levels do not exceed 30 to 40 ppb. What will be the likely result of this policy?	
A)	The occurrences of frog abnormalities will gradually decline.	
B)	Abnormalities will continue to appear in frogs.	
C)	No new abnormalities in frogs will appear.	
D)	Abnormal frogs that reproduce will have offspring that all develop normally.	
E)	Both c and d	

67.	A scientific hypothesis	
A)	can be falsified through predictions.	
B)	is used to make untestable predictions.	
C)	is based on observations.	
D)	cannot be tested by experimentation.	
E)	cannot be tested by observational analysis.	

68.	Comparative experiments are designed to answer questions that require	
A)	experimental groups and control groups.	
B)	little or no data collection.	
C)	a final, definitive answer.	
D)	the collection of qualitative data.	
E)	observation and comparison rather than controlled variables.	

69.	A biologist listens to frogs singing at a local pond and hypothesizes that the sounds are mating calls. What would be the next step in the hypothesis–prediction method?	
A)	Controlling an environment	
B)	Making an observation	
C)	Forming a hypothesis	
D)	Making a prediction	
E)	Testing a prediction	

70.	A biologist hypothesizes that the sounds made by lions at night in the Serengeti are territoriality calls and predicts that two lions inhabiting the same territory will roar even louder. She selects an area inhabited by one lion, records its calls, and plays them back in the same area. She records her observations, and notes that the lion does indeed roar more often as a result of this experiment. What would be the next step in the hypothesis–prediction method?	
A)	Asking new questions	
B)	Making an observation	
C)	Forming a hypothesis	
D)	Making a prediction	
E)	Testing a prediction	

71.	The advantage of controlled scientific experiments is that	
A)	all variables except one are held constant.	
B)	the hypothesis can be proven correct.	
C)	patterns can be predicted.	
D)	investigations can be carried out in the field.	
E)	a massive amount of data can be synthesized.	

72.	A comparative experiment	
A)	has only independent variables.	
B)	has only one dependent variable.	
C)	compares one independent variable with one dependent variable.	
D)	starts with groups or samples that are as similar as possible.	
E)	starts with the prediction that there will be a difference between groups or samples.	

73.	A rapid decline of amphibian populations has been observed worldwide. Which of the following could not be a reasonable hypothesis to explain this decline?	
A)	A fungal disease	
B)	Increased exposure to ultraviolet radiation	
C)	Exposure to agricultural chemicals	
D)	Exposure to atrazine	
E)	Deaths from natural causes	

74.	Which statement about statistical analysis in science is true?	
A)	Statistical methods are applied to data in order to prove that the null hypothesis is incorrect.	
B)	Statistical tests analyze variation to determine whether the variation is due to chance.	
C)	Statistical tests can be used to evaluate results from controlled experiments but not comparative experiments.	
D)	Scientists use statistics to prove their conclusions are true.	
E)	Statistics are used to measure the probability that an observed difference is due to chance.	

75.	A statistical test starts with	
A)	a null hypothesis.	
B)	deductive logic.	
C)	inductive logic.	
D)	a hypothesis.	
E)	a model system.	

76.	Which question can be directly answered through controlled experiments?	
A)	Are bees more attracted to red roses than to yellow roses?	
B)	Are red roses more beautiful than yellow roses?	
C)	Did an asteroid hitting Earth cause the mass extinction of dinosaurs?	
D)	When did the first life forms appear on Earth?	
E)	Is the increase in the severity of storms being caused by climate change?	

77.	Which question cannot be answered by means of the hypothesis‒prediction approach?	
A)	Are eastern meadowlark populations declining faster than western meadowlark populations?	
B)	Is the song of the western meadowlark prettier than that of the eastern meadowlark?	
C)	Do eastern and western meadowlarks interbreed?	
D)	Do meadowlarks benefit from prairie habitat restoration?	
E)	Have the migration paths of western meadowlarks been affected by climate change?	

78.	Scientific explanations for a natural phenomenon	
A)	can be tested only in the laboratory.	
B)	are always based on an ethical point of view.	
C)	are based on reproducible and quantifiable observations.	
D)	are based on hypotheses.	
E)	cannot be rejected.	

79.	Which statement represents a scientific point of view?	
A)	Earth was created by a supernatural force.	
B)	The positions of the sun, moon, and stars provide guidance for making decisions.	
C)	Inner strength comes from the beauty in nature.	
D)	Testing the effect of antibiotics on pathogens can lead to tools for fighting disease.	
E)	Meditation helps to solve ethical problems.	

80.	Many possible applications of scientific knowledge raise ethical issues for some people. Which application, however, would be rejected by all responsible scientists?	
A)	Selecting the sex of one's children	
B)	Using stem cells as part of medical treatments	
C)	Modifying the human genome	
D)	Using scientific knowledge to dictate how the world ought to be	
E)	All of the above would be rejected by scientists.	

81.	Frogs eat insects, insects ingest the tissue of plant leaves, and plants derive their energy from the sun through photosynthesis. Assuming that energy conversions are not 100 percent efficient, the total biomass of animals should be _______ than that of plants.	

82.	Most living organisms consist of one or more _______ and can regulate their _______ environment.	

83.	Currently, scientists agree with the estimate that life on Earth first appeared approximately _______ years ago.	

84.	Fatty acids were the critical ingredient in the enclosure of biological molecules in _______ films because these molecules are not _______ in water.	

85.	The use of energy from sunlight to synthesize complex molecules is known as _______.	

86.	Prokaryotes acquired the ability to photosynthesize about _______ years ago.	

87.	The total chemical activity of a living organism is called its _______.	

88.	Scientists have concluded that the ability of nucleic acids to self-replicate and serve as templates was a critical step in the chemical evolution of life that preceded the enclosure of complex proteins and other biological molecules by membranes. Considering that self-replication of nucleic acids arose in the absence of membranes, life most likely began in (shallow/deep) _______ seas where reactant concentrations were the (least/most) _______ diluted.	

89.	The two organelles within cells that are thought to have arisen by endosymbosis are _______ and _______.	

90.	In contrast to eukaryotic cells, prokaryotes lack intracellular compartments called _______.	

91.	A Pacific tree frog with the scientific nomenclature of Hyla regilla belongs to the genus _______.	

92.	A _______ tree shows the evolutionary relationships among species.	

93.	Multicellular organisms that are photosynthetic belong to the branch of the Eukarya domain called _______.	

94.	Fungi and animals are _______, whereas protists are _______.	

95.	There are six different evolutionary groups of the unicellular eukaryotes known as protists. Based upon the way in which distinctions are made among the three domains, these six groups of protists were most likely differentiated on the basis of _______ data.	

96.	Single-celled organisms that lack discrete intracellular compartments belong to the domains _______ and _______.	

97.	For more than a billion years, organisms in the three domains of _______, _______, and _______ have evolved separately from one another.	

98.	A group of individuals of the same species that interact is called a(n) _______; a number of such groups that live and interact in the same area is called a(n) _______; and the latter groupings, along with the nonliving environment, constitute the _______.	

99.	When a product of a system slows down an earlier process, it's called _______; when a product speeds up an earlier process, it's called _______.	

100.	The total of all the information encoded by an organism's genes constitutes its _______.	

101.	In the emerging field of _______, biologists and computer scientists work in close association to develop new computational tools to organize, process, and study comparative genomic databases.	

102.	Structural, physiological, or behavioral traits that enhance an organism's chance of survival and reproduction in its environment are called _______.	

103.	After making observations and coming up with questions, scientists apply logic in order to propose a possible explanation, which is called a(n) _______.	

104.	Observations or experimental results that are novel or unexpected have the potential to _______ a hypothesis.	

105.	The _______ hypothesis states that the observed differences in an experiment are the result of randomness or chance.	

106.	Platelets are cell fragments that are critical for blood clotting, a process that involves the release of proteins from platelet storage granules. Platelet granules contain approximately 300 different proteins. One hypothesis about the packaging of proteins into these granules is that each protein is delivered in precisely measured amounts to each granule. An alternative hypothesis is that each protein is targeted to the individual storage granules randomly. The second hypothesis is an example of a _______ hypothesis.	

107.	There is some controversy about whether viruses are living organisms. Based on what scientists consider to be typical of living organisms, what arguments could you use to support the claim that a virus is not a living organism?	

108.	A computer virus is capable of replicating itself. What other features of a computer virus are similar to those of a living organism? What features distinguish it from a living organism?	

Use the following to answer questions 109-110:

Refer to the figure below showing life's “timeline.”

109.	Based on the figure, which depicts Earth's history on a scale of a 30-day month, what can you conclude about the organisms that first evolved the ability to photosynthesize?	

110.	Imagine that you were to set an alarm clock to go off at the time represented on the 30-day timeline when modern humans arose. What day and time would you set the alarm clock for?	

Use the following to answer questions 111-112:

Refer to the diagram below showing the evolutionary tree of life.

111.	According to the relationships indicated by this phylogeny, which groups of organisms have mitochondria and which groups have chloroplasts?	

112.	Based on the diagram, how would you describe the relationship of fungi to plants and animals?	

113.	Refer to the illustration below. Within the hierarchy of ecological systems, what level is represented in the illustration, and which details in the illustration lead to this answer?

114.	Refer to the diagram below showing various feedback loops. If component C reacts to increase the rate of the conversion of component A to component B, what type of feedback loop is this, and how will it affect the amount of component C?

115.	The amount of thyroid hormone released by the thyroid gland is controlled by the pituitary gland. When thyroid hormone levels in the blood are low, the pituitary gland secretes thyroid-stimulating hormone (TSH), which in turn stimulates the thyroid gland to produce more thyroid hormone. When levels of thyroid hormone in the blood are normal, TSH production is decreased. What type of feedback loop does this represent? If a person has an autoimmune disease that is destroying the thyroid gland, what would likely happen to the TSH levels?	

Use the following to answer questions 116-117:

Refer to the figure below showing DNA as life's “blueprint.”

116.	From the figure above, what can you conclude about the composition of genes, their location, and their function?	

117.	The exposure of DNA to excessive levels of ultraviolet radiation produces thymine (a nucleotide) dimers, which, if unrepaired, can lead to the production of skin cancer. Which structures in the diagram could be affected by this mutation?	

118.	If you wanted to do a year-long study on evolution using an organism in the laboratory, would you use bacteria or mice, and why?	

119.	Refer to the diagram below showing the steps in the scientific method. You have decided to conduct a scientific experiment about the effects of coffee on test taking. Step 1 in your experiment is the observation that when you drink a cup of coffee with sugar and cream before taking test, you feel more focused. What question would you ask for Step 2, what hypothesis would you form for Step 3, and what prediction would you make for Step 4 of your experiment?

120.	The graph below shows the results of a study of atrazine exposure in male frogs. What conclusions can be deduced from these results regarding the effects of low versus high levels of atrazine and the relationship between the level of atrazine exposure and its effects?

121.	The figure below shows comparative experiments performed to study the incidence of abnormalities in frogs from environments with very different levels of atrazine. What would be the most likely null hypothesis for this study?

Answer Key

1.	B	
2.	D	
3.	B	
4.	A	
5.	E	
6.	D	
7.	A	
8.	C	
9.	D	
10.	A	
11.	D	
12.	E	
13.	B	
14.	D	
15.	B	
16.	C	
17.	B	
18.	C	
19.	C	
20.	D	
21.	D	
22.	A	
23.	C	
24.	E	
25.	D	
26.	B	
27.	A	
28.	A	
29.	D	
30.	B	
31.	E	
32.	D	
33.	B	
34.	E	
35.	A	
36.	E	
37.	B	
38.	C	
39.	C	
40.	B	
41.	B	
42.	E	
43.	A	
44.	C	
45.	B	
46.	C	
47.	B	
48.	D	
49.	D	
50.	D	
51.	C	
52.	A	
53.	D	
54.	C	
55.	D	
56.	C	
57.	B	
58.	B	
59.	C	
60.	D	
61.	E	
62.	C	
63.	A	
64.	E	
65.	C	
66.	B	
67.	C	
68.	E	
69.	D	
70.	A	
71.	A	
72.	E	
73.	E	
74.	E	
75.	A	
76.	A	
77.	B	
78.	C	
79.	D	
80.	D	
81.	less	
82A.	cell	
82B.	internal	
83.	4 billion	
84A.	membranous	
84B.	soluble	
85.	photosynthesis	
86.	2.7 billion	
87.	metabolism	
88A.	shallow	
88B.	least	
89A.	mitochondria	
89B.	chloroplasts	
90.	organelles	
91.	Hyla	
92.	phylogenetic	
93.	Plants	
94A.	multicellular	
94B.	unicellular	
95.	molecular	
96A.	Archaea	
96B.	Bacteria	
97A.	Archaea	
97B.	Bacteria	
97C.	Eukarya	
98A.	population	
98B.	community	
98C.	ecosystem	
99A.	negative feedback	
99B.	positive feedback	
100.	genome	
101.	bioinformatics	
102.	adaptations	
103.	hypothesis	
104.	falsify	
105.	null	
106.	null	
107.	Viruses are not composed of cells and are incapable of living independently. They depend on host cells to carry out physiological functions.	
108.	A computer virus is made up of a common set of building blocks, and it can evolve via mutation and selection. However, unlike living organisms, it does not depend on structurally complex parts and it does not convert molecules from its environment into new molecules.	
109.	These organisms were prokaryotes, and they arose before the evolution of cells containing organelles.	
110.	5 minutes before midnight on day 30.	
111.	Only the organisms classified within the Eukarya have mitochondria—Bacteria and Archaea do not. Only plants and some protists have chloroplasts.	
112.	Fungi are more closely related to animals then they are to plants.	
113.	The diagram shows a community, because several populations of organisms that interact with one another are shown.	
114.	It is a positive feedback loop, and it will cause an increase in the amount of component C.	
115.	It is a negative feedback loop. In the person with an autoimmune disease that destroys the thyroid, TSH levels would rise.	
116.	Genes are composed of DNA and they occupy a stretch of the DNA molecule. Genes are used in some way to make proteins.	
117.	The mutation affects the structure of nucleotides, and therefore the structure of DNA, and genes. The altered structure of the genes would, in turn, affect the structure of proteins.	
118.	It would be better to use bacteria, because their generation time is far shorter than that of mice, and it is easier to grow populations of bacteria.	
119.	(Answers will vary.)
Step 2: Is it the caffeine or the sugar or the cream in the coffee that is making me feel more focused?
Step 3: I hypothesize that it is the caffeine in the coffee that has this effect and not either the sugar or the cream.
Step 4: I predict that drinking black coffee before an exam will have the same effect as drinking coffee with sugar and cream, but that drinking water with cream and sugar will not have this effect.	
120.	Low levels of atrazine are more dangerous to amphibians than higher levels, showing that the effect of the atrazine exposure is not proportional to the level of exposure.	
121.	The null hypothesis would be that differences in the percentage of gonadal abnormalities among sites with varied atrazine levels could be random sampling effects.