Which of the following is not true of vertically oriented phylogenetic trees?
a. Each branch point represents a point in absolute time
b. Organisms represented at the base of such trees are ancestral to those represented at higher levels
c. The more branch points that occur between two taxa, the more divergent their DNA sequences should be
d. The common ancestor represented by the highest branch point existed more recently in time than the common ancestors represented at lower branch points.
e. The more branch points there are, the more instances of cladogenesis are represented
A
The lakes of northern Minnesota contain many similar species of damselflies of the genus Enallagma that have apparently undergone speciation from ancestral stock since the last glacial retreat about 10,000 years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?
a. nuclear DNA
b. mitochondrial DNA
c. small nuclear RNA
d. ribosomal RNA
e. amino acids in proteins
B
The first genetic material was most likely a(n)
a. DNA polymer
b. DNA oligonucleotide
c. RNA polymer
d. protein
e. protein enzyme
C
Which of the following has not yet been synthesized in laboratory experiments studying the origin of life?
a. liposomes
b. liposomes with selectively permeable membranes
c. oligopeptides and other oligomers
d. protobionts that use DNA to program protein synthesis
e. amino acids
D
How could RNA have become involved in the mechanism for protein translation?
a. Only ribozymes were available as catalysts
b. RNA replication is enhanced if proteins are produced
c. Natural selection acted against autocatalytic protein formation
d. DNA was not available for protein translation
e. Natural selection favored RNA molecules that synthesized catalytic proteins
E
Which measurement would help determine absolute dates by radiometric means?
a. the accumulation of the daughter isotope
b. the loss of parent isotopes
c. the loss of daughter isotopes
d. all three of these
e. only A and B
E
If the half-life of carbon-14 is about 5,730 years, then a fossil that has one-eight the normal proportion of carbon-14 to carbon-12 is probably ____ years old
a. 1,400
b. 2,800
c. 11,200
d. 16,800
e. 22,400
D
How many half-lives should have elapsed if 12.5% of the parent isotope remains in a fossil at the time of the analysis?
a. one
b. two
c. three
d. four
e. five
C
Arrange these events from earliest to most recent.
1. emission of lava in what is now Siberia at time of Permian extinctions
2. emission of lava that solidified at the same time as iron-bearing terrestrial rocks began to rust
3. emission of lava that solidified at the same time as the first banded iron formations formed
4. emission of lava in what is now India at time of Cretaceous extinctions
a. 3, 1, 2, 4
b. 3, 2, 1, 4
c. 3, 1, 4, 2
d. 1, 3, 2, 4
e. 1, 2, 3, 4
B
The ancestors of which free-living cells were the earliest autotrophs to contribute to the formation of Earth's oxidizing atmosphere?
a. cyanobacteria
b. chloroplasts
c. mitochondria
d. seaweeds
e. endosymbionts
A
Jams, jellies, preserves, honey, and other foodstuffs with a high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. This is because bacteria that encounter such an environment
a. undergo death by plasmolysis
b. are unable to metabolize the glucose or fructose, and thus starve to death
c. undergo death by lysis
d. are obligate anaerobes
e. are unable to swim through these thick and viscous materials
A
Prokaryotes have ribosomes different from those of eukaryotes. Because of this, which of the following is true?
a. Some selective antibiotics can block protein synthesis of bacteria without harming the eukaryotic host
b. Eukaryotes did not evolve from prokaryotes
c. Translation can occur at the same time as transcription in eukaryotes but not in prokaryotes
d. Some antibiotics can block the formation of cross-links in the peptidoglycan walls of bacteria
e. Prokaryotes are able to use a much greater variety of molecules as food sources than can eukaryotes
A
Mycoplasmas are bacteria that lack cell walls. On the basis of this structural feature, which of the statements below is true about mycoplasmas?
a. They are gram-negative
b. They are subject to lysis in hypotonic conditions
c. They lack a cell membrane as well
d. They undergo ready fossilization in sedimentary rock
e. They posses typical prokaryotic flagella
B
Which of the two groups of archaea should have SSU-rRNA sequences that are most similar to each other?
1. extreme halophiles
2. cyanobacteria
3. methanogens
4. alpha proteobacteria
5. Korarchaeota
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 2 and 5
e. 3 and 5
B
Which of the following statements about prokaryotes is correct?
a. Bacterial cells conjugate to mutually exchange genetic material
b. Their genetic material is confined within a nuclear envelope
c. They divide by binary fission, without mitosis or meiosis
d. The persistence of bacteria throughout evolutionary time is due to genetic similarity
e. Genetic variation in bacteria is not known to occur, nor should it occur, because of their asexual mode of reproduction
C
Modes of obtaining nutrition, used by at least some bacteria, include all of the following except
a. chemoautotrophy
b. photoautotrophy
c. heteroautotrophy
d. chemoheterotrophy
e. photoheterotrophy
C
Match the numbered terms below to the following descriptions
1. autotroph
2. heterotroph
3. phototroph
4. chemotroph
an organism that obtains its energy from chemicals
a. 1 only
b. 2 only
c. 3 only
d. 4 only
e. 1 and 4
D
Match the numbered terms below to the following descriptions
1. autotroph
2. heterotroph
3. phototroph
4. chemotroph
a prokaryote that obtains both energy and carbon as it decomposes dead organisms
a. 1 only
b. 4 only
c. 1 and 3
d. 2 and 4
e. 1, 3, and 4
D
Which of the following is the correct order, from most external to most internal?
1. cell wall
2. plasma membrane
3. capsule
a. 1, 2, 3
b. 1, 3, 2
c. 2, 1, 3
d. 3, 2, 1
e. 3, 1, 2
E
Given that the enzymes that catalyze nitrogen fixation are poisoned by oxygen, what are two "strategies" that nitrogen-fixing prokaryotes might use to protect these enzymes from oxygen?
1. couple them with photosystem II
2. sequester them in gas-impermeable membranes
3. be obligate anaerobes
4. be strict aerobes
5. sequester these enzymes in specialized cells or compartments that inhibit oxygen entry
a. 1 and 4
b. 2 and 4
c. 2 and 5
d. 3 and 4
e. 3 and 5
E
Protists are alike in that all are
a. multicellular
b. photosynthetic
c. marine
d. nonparasitic
e. eukaryotic
E
Which organisms represent the common ancestor of all photosynthetic plastid found in eukaryotes?
a. autotrophic euglenids
b. diatoms
c. dinoflagellates
d. red algae
e. cyanobacteria
E
The current state of the revision of "protistan" taxonomy is an example of which feature of good scientific practice?
a. the need to suspend judgment until enough evidence is available to make an informed decision
b. the need to base hypothetical phylogenies solely on fossil evidence
c. the need to be willing to change or drop one's hypotheses when the data warrant it
d. the need to avoid sampling techniques that can introduce bias
e. both A and C
E
Organisms classified as Euglenozoa have previously been classified as protozoans, protista, plants, and animals. Why the confusion?
a. Like protozoans, they are unicellular
b. Like animals, many are heterotrophic
c. Like plants, many are photosynthetic
d. A and B only
e. A, B, and C
E
Which taxonomic group containing eukaryotic organisms is thought to be directly ancestral to the plant kingdom?
a. golden algae
b. radiolarians
c. foraminiferans
d. apicomplexans
e. green algae
E
The largest seaweeds belong to which group?
a. cyanobacteria
b. red algae
c. green algae
d. brown algae
e. golden algae
D
A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following?
a. thalli
b. bladders
c. blades
d. holdfasts
e. gel-forming polysaccharides
D
Which of the following do all fungi have in common?
a. meiosis in basidia
b. coenocytic hyphae
c. sexual life cycle
d. absorption of nutrients
e. symbioses with algae
D
Which of the following terms is not properly associated with the fungi as a kingdom?
a. decomposers
b. sexual and asexual spores
c. ecologically important
d. polyphyletic
e. absorptive nutrition
D
In fungi, karyogamy does not immediately follow plasmogamy, which
a. means that sexual reproduction can occur in specialized structures
b. results in more genetic variation during sexual reproduction
c. allows fungi to reproduce asexually most of the time
d. results in heterokaryotic cells
e. is strong support for the claim that fungi are not truly eukaryotic
D
The most recent common ancestor of all land plants was most similar to modern-day members of which group?
a. cyanobacteria
b. red algae
c. Charophycea
d. brown algae
e. golden algae
C
In animals cells and in the meristem cells of land plants, the nuclear envelope disintegrates during mitosis. This disintegration does not occur in the cells of most protists and fungi. According to our current knowledge of plant evolution, which group of organisms should feature mitosis most similar to that of land plants?
a. unicellular chlorophytes
b. diatoms
c. charophyceans
d. red algae
e. multicellular chlorophytes
C
Bryophytes have all of the following characteristics except
a. multicellularity
b. specialized cells and tissues
c. lignified vascular tissue
d. walled spores in sporangia
e. a reduced, dependent sporophyte
C
Which of the following characteristics, if observed in an unidentified green organism, would make it unlikely to be a charophycean?
a. phragmoplast
b. peroxisome
c. apical meristem
d. chlrophylls a and b
e. rosette cellulose-synthesizing complex
C
Plant spores give rise directly to
a. sporophytes
b. gametes
c. gametophytes
d. sporophylls
e. seeds
C
A botanist discovers a new species of plant in a tropical rainforest. After observing its anatomy and life cycle, the following characteristics are noted: flagellated sperm, xylem with tracheids, separate gametophyte and sporophyte generations, and no seeds. This plant is probably most closely related to
a. mosses
b. Chara
c. ferns
d. liverworts
e. flowering plants
C
Which of these is most important in making the typical seed more resistant to adverse conditions than the typical spore?
a. a different type of sporopollenin
b. an internal reservoir of liquid water
c. integument(s)
d. ability to be dispersed
e. waxy cuticle
C
Gymnosperms differ from both extinct and extant ferns because they
a. are woody
b. have macrophylls
c. have pollen
d. have sporophylls
e. have spores
C
Which structure is common to both gymnosperms and angiosperms?
a. male strobilus
b. carpel
c. ovule
d. ovary
e. anthers
C
What is true about stamens, sepals, petals, and pine cone scales?
a. They are female reproductive parts
b. None are capable of photosynthesis
c. They are modified leaves
d. They are found on flowers
e. They are found on angiosperms
C
Which of the following terms or structures is not associated with animals?
a. eukaryotic
b. cell wall
c. desmosome
d. zygote
e. blastula
B
What is the probable sequence in which of the following clades of animals originated, from earliest to most recent?
1. tetrapods
2. vertebrates
3. deuterostomes
4. amniotes
5. bilaterians
a. 5, 3, 2, 4, 1
b. 5, 3, 2, 1, 4
c. 5, 3, 4, 2, 1
d. 3, 5, 4, 2, 1
e. 3, 5, 2, 1, 4
B
The major branches of Eumetazoa are the Radiata and the Bilateria. These names refer to what characteristic of these animals?
a. size
b. body symmetry
c. embryonic cleavage
d. types of appendages
e. presence or absence of a nucleus in their cells
B
Which of the following is descriptive of protosomes?
a. spiral and indeterminate cleavage, blastopore becomes mouth, schizocoelous development
b. spiral and determinate cleavage, blastopore becomes mouth, schizocoelous development
c. spiral and determinate cleavage, blastopore becomes anus, enterocoelous development
c. radial and determinate cleavage, blastopore becomes anus, enterocoelous development
d. radial and determinate cleavage, blastopore becomes mouth, schizocoelous development
B
What is characteristic of all ecdysozoans?
a. the deuterostome condition
b. some kind of exoskeleton, or hard outer covering
c. a pseudocoelom
d. agile, speedy, and powerful locomotion
e. the diploblastic condition
B
A shared derived characteristic for members of the arthropod subgroup that includes spiders would be the presence of
a. chelicerae
b. an open circulatory system
c. an exoskeleton
d. a cuticle
e. a cephalothorax
A
While working in your garden, you discover a worm-like, segmented animal with two pairs of jointed legs per segment. The animal is probably a
a. millipede
b. caterpillar
c. centipede
d. polychaete worm
e. sow bug
A
Which of the following is a characteristic of adult echinoderms?
a. secondary radial symmetry
b. spiral cleavage during early embryonic development
c. gastrovascular cavity
d. exoskeleton
e. a lophophore
A
In a tide pool, a student encounters an organism with a hard outer covering that contains much calcium carbonate, an open circulatory system, and gills. The organism could potentially be a crab, a shrimp, a barnacle, or a bivalve. Which structure below would allow for the most certain identification?
a. a mantle
b. a heart
c. a body cavity
d. a lophophore
e. eyes
A
Which extant chordate group is postulated to be most like the earliest chordates in appearance?
a. Cephalochordata
b. adult Urochordata
c. Amphibia
d. Reptilia
e. Chrondrichthyes
A
Which of the following types of plants is not able to self-pollinate?
a. dioecious
b. monoecious
c. complete
d. wind-pollinated
e. insect-pollinated
A
In flowering plants, pollen is released from the
a. anther
b. stigma
c. carpel
d. filament
e. pollen tube
A
Within the female gametophyte, three miotic divisions of the megaspore produce
a. three antipodal cells, two polar nuclei, one egg, and two synergids
b. the triple fusion nucleus
c. three pollen grains
d. two antipodal cells, two polar nuclei, two eggs, and two synergids
e. a tube nucleus, a generative cell, and a sperm cell
A
A person working with plants may remove apical dominance by doing which of the following
a. pruning
b. deep watering of the roots
c. fertilizing
d. transplanting
e. feeding the plants nutrients
A
Land plants are composed of all of the following tissue types except
a. mesodermal
b. epidermal
c. meristematic
d. vascular
e. ground tissue
A
All of the following normally enter the plant through the roots except
a. carbon dioxide
b. nitrogen
c. potassium
d. water
e. calcium
A
What is the main cause of guttation in plants?
a. root pressure
b. transpiration
c. pressure flow in phloem
d. plant injury
e. condensation of atmospheric water
A
The value for YW in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (YW = -0.23), net water flow would
a. be from the tissue into the sucrose solution
b. be from the sucrose solution into the tissue
c. be in both directions and the concentrations would remain equal
d. occur only as ATP was hydrolyzed in the tissue
e. be impossible to determine from the values given here
A
The polarity of a plant is established when
a. the zygote divides
b. cotyledons form at the shoot end of the embryo
c. the shoot-root axis is established in the embryo
d. the primary root breaks through the seed coat
e. the shoot first breaks through the soil into the light as the seed germinates
A
Which of the following is true of bark?
a. It is composed of phloem plus periderm
b. It is associated with annuals but not perennials
c. It is formed by the apical meristems
d. It has no identifiable function in trees
e. It forms annual rings in deciduous trees
A
The following question is based on parts of a growing primary root
I. root cap
II. zone of elongation
III. zone of cell division
IV. zone of cell maturation
V. apical meristem
Which of the following is the correct sequence from the growing tips of the root upward?
a. I, II, V, III, IV
b. III, V, I, II, IV
c. II, IV, I, V, III
d. IV, II, III, I, V
e. I, V, III, II, IV
E
The vascular system of a three-year-old eudicot stem consists of
a. 3 rings of xylem and 3 of phloem
b. 2 rings of xylem and 2 of phloem
c. 2 rings of xylem and 1 of phloem
d. 2 rings of xylem and 3 of phloem
e. 3 rings of xylem and 1 of phloem
E
The amount and direction of movement of water in plants can always be predicted by measuring which of the following?
a. air pressure
b. rainfall
c. proton gradients
d. dissolved solutes
e. water potential (YW)
E
Guard cells do which of the following?
a. protect the endodermis
b. accumulate K+ and close the stomata
c. contain chloroplasts that import K+ directly into the cells
d. guard against mineral loss through the stomata
e. help balance the photosynthesis-transpiration compromise
E
The epithelium best adapted for a body surface subject to abrasion is
a. simple squamous
b. simple cuboidal
c. simple columnar
d. stratified columnar
e. stratified squamous
E
What do fibroblasts secrete?
a. fats
b. chondroitin sulfate
c. interstitial fluids
d. calcium phosphate for bone
e. proteins for connective fibers
E
What holds bones together at joints?
a. cartilage
b. Haversian systems
c. loose connective tissue
d. tendons
e. ligaments
E
What is peristalsis?
a. a process of fat emulsification in the small intestine
b. voluntary control of the rectal sphincters regulating defecation
c. the transport of nutrients to the live through the hepatic portal vessel
d. a common cause of loss of appetite, fatigue, and dehydration
e. smooth muscle contractions that move food through the alimentary canal
E
What is the main nitrogenous waste excreted by birds?
a. ammonia
b. nitrate
c. nitrite
d. urea
e. uric acid
E
Which of the following levels of organization is arranged in the correct sequence from most to least inclusive?
a. community, ecosystem, individual, population
b. ecosystem, community, population, individual
c. population, ecosystem, individual, community
d. individual, population, community, ecosystem
e. individual, community, population, ecosystem
B
Ecology as a discipline directly deals with all of the following levels of biological organization except
a. population
b. cellular
c. organismal
d. ecosystem
e. community
B
You are working for the Environmental Protection Agency and researching the effect of a potentially toxic chemical in drinking water. There is no documented scientific evidence showing that the chemical is toxic, but many suspect it to be a health hazard. Using the precautionary principle, what would be a reasonable environmental policy?
a. Establish no regulations until there conclusive scientific studies
b. Set the acceptable levels of the chemical conservatively low, and keep them there unless future studies show that they can be safely raised
c. Set the acceptable levels at the highest levels encountered, and keep them there unless future studies demonstrate negative health effects
d. Caution individuals to use their own judgment in deciding whether to drink water from a potentially contaminated area
e. Establish a contingency fund to handle insurance claims in the event that the chemical turns out to produce negative health effects
B
All of the following would have a direct effect on the amount of precipitation in an area except
a. air circulation cells
b. continental drift
c. ocean currents
d. mountain ranges
e. evaporation from vegetation
B
Polar regions are cooler than the equator because
a. there is more ice at the poles
b. sunlight strikes the poles at an oblique angle
c. the poles are farther from the sun
d. the poles have thicker atmosphere
e. the poles are permanently tilted away from the sun
B
Which marine zone would have the lowest rates of primary productivity (photosynthesis)?
a. pelagic
b. abyssal
c. neritic
d. continental shelf
e. intertidal
B
Phytoplankton is most frequently found in which of the following zones?
a. oligotrophic
b. photic
c. benthic
d. abyssal
e. aphotic
B
You are interested in studying how organisms react to a gradient of abiotic conditions and how they coexist in this gradient. The best biome in which to conduct such a study is
a. mountains
b. an intertidal zone
c. a river
d. tropical rainforest
e. an eutrophic lake
B
Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of
a. parallel evolution
b. convergent evolution
c. allopatric speciation
d. introgression
e. gene flow
B
Fire suppression by humans
a. will always result in an increase in the number of species in a given biome
b. can change the species composition within biological communities
c. will result ultimately in sustainable production of increased amounts of wood for human use
d. is necessary for the protection of threatened and endangered forest species
e. both C and D
B
All of the following phrases could characterize a population except
a. interacting individuals
b. dispersion
c. density
d. several species
e. boundaries
D
Uniform spacing patterns in plants such as the creosote bush are most often associated with
a. chance
b. patterns of high humidity
c. the random distribution of seeds
d. antagonistic interactions among individuals in the population
e. the concentration of resources within the population's range
D
Which curve best describes survivorship in a marine crustacean that molts?
a. A
b. B
c. C
d. D
e. E
D
Life history strategies usually result from
a. environmental pressures
b. natural selection
c. conscious choice
d. A and B only
e. A, B, and C
D
Natural selection has led to the evolution of diverse natural history strategies, which have in common
a. many offspring per reproductive episode
b. limitation by density-dependent limiting factors
c. adaptation to stable environments
d. maximum lifetime reproductive success
e. relatively large offspring
D
Which of the following aspects of an organism's life is least relevant to its life history?
a. number of offspring per reproductive bout
b. age at which it first reproduces
c. frequency of reproduction
d. frequency of dispersal
e. all of the above
D
Imagine that you are managing a large ranch. The graph will
a. be a diagonal line, getting higher with each generation
b. look like an "S," increasing with each generation
c. look like an upside-down "U."
d. look like a "J," increasing with each generation
e. look like none of the above
D
Carrying capacity (K)
a. is calculated as the product of annual per capita birth rate (r)
b. remains constant in the presence of density-dependent population regulation
c. differs among species, but does not vary within a given species
d. is often determined by energy limitation
e. is always eventually reached in any population
D
Logistic growth of a population is represented by dN/dt =
a. A
b. B
c. C
d. D
e. E
D
In models of sigmoidal (logistic) population growth,
a. population growth rate slows dramatically as N approaches K
b. new individuals are added to the population most rapidly at intermediate population sizes
c. density-dependent factors affect the rate of population growth
d. All of the above are true
e. Only A and C are true
D
Many homeowners mow their lawns during the summer. Which of the following alternatives would cause the least disturbance to local ecosystems?
a. Don't mow the lawn
b. Collect the clippings and burn them
c. Either collect the clippings and add them to a compost pile, or don't collect the clippings and let them decompose on the lawn
d. Collect the clippings
e. Dig up the lawn and cover the yard with asphalt
C
Subtraction of which of the following will convert gross primary productivity into net primary productivity?
a. the energy contained in the standing crop
b. the energy used by heterotrophs in respiration
c. the energy used by autotrophs in respiration
d. the energy fixed by photosynthesis
e. all solar energy
C
How is that the open ocean produces highest NPP, yet NPP per square meter is relative low?
a. It contains greater concentrations of nutrients
b. it receives a greater amount of solar energy per unit area
c. It has the greatest total area
d. It contains more species of organisms
e. Its producers are generally much smaller than its consumers
C
In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are
a. Rhizobium bacteria
b. nitrifying bacteria
c. denitrifying bacteria
d. methanogenic protozoans
e. nitrogen-fixing bacteria
C
If you were tracking a nutrient molecule through an ecosystem, which of the following statements would you expect to verify?
a. Molecules move through all ecosystems at the same constant rate, as the laws of physics would predict
b. Because of the liquid nature
c. Vertical mixing is essential for high productivity in aquatic ecosystems
d. A and B only
e. A, B, and C
C
The high levels of pesticides found in birds of prey is an example of
a. eutrophication
b. predation
c. biological magnification
d. the green world hypothesis
e. chemical cycling through an ecosystem
C
If the flow of energy in an arctic ecosystem goes through a simple food chain from seaweeds to fish to seals to polar bears, then which of the following is true?
a. Polar bears can provide
b. The total energy content
c. Polar bear meat probably contains the highest concentrations of fat-soluble toxins
d. Sals are more
e. The carnivores can provide
C
A. Green world hypothesis
B. turnover
C. biological magnification
D. greenhouse effect
E. cultural eutrophication
Caused excessively high levels of DDT in fish-eating birds
a. A
b. B
c. C
d. D
e. E
C
Estimates of current rates of extinction
a. indicate that we have reached
b. suggest that one-half of all animal
c. indicate that rates may be 1,000 times higher than at any other time in the last 100,000 years
d. B and C only
e. A, B, and C
C
Extinction is a natural phenomenon. Why then do we say that we are now in a biodiversity crisis?
a. Humans are ethically
b. Scientists have finally identified
c. The current rate of extinction is as much as 1,000 times much higher than at any other time in the last 100,000 years
d. Humans have greater medical needs
e. Most biodiversity hot spots have been
C
Although extinction is a natural process, current extinctions are of concern to environmentalists because
a. more animals than ever
b. most current extinctions are
c. the rate of extinction is unusually high
d. current extinction is primarily
e. none of the above
C