Biol 110 Exam 1
Mutations are mistakes that usually occur during __________.
DNA replication
You are an archaeologist who has just found an ancient fire ring containing charcoal fragments. You send these fragments to the lab for carbon-14 analysis. The report comes back that these fragments have 1/4 the amount of carbon-14, compared to modern wood. You use 5730 years as the half-life of carbon-14. You conclude the charcoal is about _____. a) 11,460 years old b) 5730 years old c) 2865 years old d) 17,190 years old
a) 11,460 years old
You find an ancient spear and apply dendrochronological methodology to discover that its growth ring pattern corresponds to 5,000 years ago. You are not satisfied with this single method and want to corroborate the date using another approach. You turn to carbon-14 methodology. If the dendrochronology data are correct, how much carbon-14 (compared to modern wood) should be present in the spear? a) About 50% b) About 25% c) About 12.5% d) About 75%
a) About 50%
Which of the following hydrocarbons has a double bond in its carbon skeleton? a) C2H4 b) C2H2 c) C3H8 d) C2H6 e) CH4
a) C2H4
____________ is when organisms of different species both benefit by living intimately for extended periods of time. a) Mutualism b) Parasitism c) Predation d) Commensalism
a) Mutualism
Which monomers make up RNA? a) Nucleotides b) Polymers c) Amino acids d) Simple sugars
a) Nucleotides
Which molecule did Carl Woese study to produce his tree of life? a) Ribosomal RNA b) DNA c) Messenger RNA d) Ribosome
a) Ribosomal RNA
If the half-life of carbon-14 is about 5,730 years, then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old? a) 16,800 b) 22,900 c) 1,400 d) 2,800 e) 11,200
b) 22,900
Prokaryotic life was present at least _________________ years ago. a) 1 billion b) 3 billion c) 1 million - 10 million d) 100 million
b) 3 billion
Ice floats. What would be the consequence to aquatic life if ice sank? a) There would be no consequence. b) Aquatic life would suffer in the winter. c) Aquatic life would suffer in the summer. d) Aquatic life would benefit in the winter.
b) Aquatic life would suffer in the winter.
A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification? a) Protista b) Archaea c) Eukarya d) Fungi e) Animalia
b) Archaea
Prokaryotes are classified as belonging to two different domains. What are the domains? a) Bacteria and Protista b) Bacteria and Archaea c) Archaea and Monera d) Bacteria and Eukarya e) Eukarya and Monera
b) Bacteria and Archaea
Carbon-14 decays into ____________. a) Lithium-7 b) Nitrogen-14 c) Carbon-13 d) Carbon-12
b) Nitrogen-14
What characteristics were used to classify organisms before Woese's tree of life analysis? a) Differences in ribosomal RNA sequences b) Presence of a membrane-bound nucleus c) Composition of the cell wall d) Number of cells in the organism
b) Presence of a membrane-bound nucleus
Which group was not described in Woese's tree of life analysis? a) Bacteria b) Prokarya c) Eukarya d) Archaea
b) Prokarya
Which statement about the genomes of prokaryotes is correct? a) Prokaryotic genomes are diploid throughout most of the cell cycle. b) Prokaryotic genomes are composed of circular chromosomes. c) Prokaryotic chromosomes are sometimes called plasmids. d) The prokaryotic chromosome is not contained within a nucleus but, rather, is found at the nucleolus. e) Prokaryotic cells have multiple chromosomes, "packed" with a relatively large amount of protein.
b) Prokaryotic genomes are composed of circular chromosomes.
A paleontologist finds a new tyrannosaur in a site she is excavating, and wishes to date the fossil. What is the most likely method she will use? a) All of these methods would provide a reliable estimate for the age of this dinosaur fossil. b) She will infer the age of the fossil by dating layers of volcanic rock above and below the stratum containing the fossil using radiometric dating. c) She will determine the fossil's age by measuring the ratio of carbon-14 to carbon-12 in the fossil. d) She will infer the age of the fossil by collecting wood fragments near the fossil and use dendrochonrology to date the wood fragments.
b) She will infer the age of the fossil by dating layers of volcanic rock above and below the stratum containing the fossil using radiometric dating.
Which statement is true about obligate anaerobes? a) They use O2 for cellular respiration and cannot grow without it. b) They are poisoned by O2. c) They will use O2 if it is present, but can obtain energy by fermentation if needed. d) They obtain energy by oxidizing ferrous ions. e) They live exclusively by cellular respiration or by anaerobic respiration.
b) They are poisoned by O2.
Antibiotic resistance is passed from parent to offspring through ____________.
binary fission
Antibiotics kill sensitive bacteria or interfere with ___________.
binary fission
DNA replication occurs during __________.
binary fission
Genetic variation propagates through a growing bacterial population via ________.
binary fission
If the half-life of carbon-14 is about 5,730 years, then a fossil that has one-eighth the normal proportion of carbon-14 to carbon-12 should be about how many years old? a) 11,200 b) 2,800 c) 17,190 d) 22,900 e) 1,400
c) 17,190
In Fred Griffith's experiments, harmless R strain pneumococcus became lethal S strain pneumococcus as the result of which of the following? 1. transduction 2. conjugation 3. transformation 4. genetic recombination a) 1, 2, and 3 b) 2 and 4 c) 3 and 4 d) 2 only e) 4 only
c) 3 and 4
Earth probably formed _____ years ago, and the first life evolved as early as _____ years ago. a) 10 billion years ago ... 4.5 billion years ago b) 3.9 million years ago ... 2.0 billion years ago c) 4.5 billion years ago ... 3.9 billion years ago d) 6,000 years ago ... 6,000 years ago e) Humans observed neither event, so there is no way to tell.
c) 4.5 billion years ago ... 3.9 billion years ago
Which of the following statements about phylogenetic trees is true? a) A monophyletic group consists of a common ancestor and some of its descendants. b) A paraphyletic group consists of an ancestral population and all of its descendants. c) A paraphyletic group consists of a common ancestor and some of its descendants. d) A paraphyletic group has not experienced lateral gene transfer.
c) A paraphyletic group consists of a common ancestor and some of its descendants.
Antibiotic resistance may be acquired from other cells through ___________.
conjugation
If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand? a) 3'-GCAAAT-5' b) 3'-TUUUCG-5' c) 3'-ATTTGC-5' d) 3'-TAAACG-5' e) 3'-UAAACG-5'
d) 3'-TAAACG-5'
Which of the following statements about the formation of polypeptides from amino acids is true? a) The reaction occurs through the addition of a water molecule to the amino acids. b) A bond can form between any carbon and nitrogen atom in the two amino acids being joined. c) Polypeptides form by condensation or hydrolysis reactions. d) A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.
d) A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.
Which of the following is not attached to the central carbon atom in an amino acid? a) An amino functional group b) A side chain ("R group") c) A carboxyl functional group d) An oxygen
d) An oxygen
A coccus bacterium, such as Streptococcus pneunoniae, would be ________________. a) rod-shaped b) fuzzy c) helical d) round
d) round
Radiocarbon dating is appropriate to use when estimating the dates of fossils deposited at the time of _________. a) the diversification of bony fishes (363 - 409 million years ago) b) the origin of most modern animal phyla (510 - 570 million years ago) c) the time at which life forms arose on Earth d) the first European occupation of the New World (less than 10,000 years ago)
d) the first European occupation of the New World (less than 10,000 years ago)
Approximately how far back in time does the fossil record extend? a) 6,000,000 years b) 3,500,000 years c) 6,000 years d) 5,000,000,000,000 years e) 3,500,000,000 years
e) 3,500,000,000 years
How does the large amount of genetic variation observed in prokaryotes arise? a) The mutation rate in prokaryotes is much higher than in eukaryotes. b) They have extremely short generation times and large populations. c) They can exchange DNA with many types of prokaryotes by way of conjugation. d) They have a relatively small genome. e) The second and third answers are correct.
e) The second and third answers are correct.
How does the large amount of genetic variation observed in prokaryotes arise? a) The mutation rate in prokaryotes is much higher than in eukaryotes. b) They have extremely short generation times and large populations. c) They can exchange DNA with many types of prokaryotes by way of horizontal gene transfer. d) They have a relatively small genome. e) The second and third answers are correct.
e) The second and third answers are correct.
The tendency of an atom to pull electrons toward itself is referred to as its _____. a) tonicity b) ionic potential c) polarity d) covalency e) electronegativity
e) electronegativity
In this molecule, what type of bond is found between the oxygen and hydrogens? a) hydrophilic b) nonpolar covalent c) hydrophobic d) ionic e) polar covalent
e) polar covalent
The earliest organisms were most likely _____. a) eukaryotic b) plants and fungi c) multicellular d) proto-cells e) prokaryotic
e) prokaryotic
Conjugation combines DNA from different cells, resulting in ___________.
genetic recombination
Genetic recombination contributes to _________.
genetic variation
Mutations contribute to ___________.
genetic variation
The rapid reproduction and large population sizes of many bacterial populations mean that even a small mutation rate can lead to considerable ____________________.
genetic variation
In theory, two daughter cells are ____________ each other and the parent cell.
genetically identical to
Antibiotic resistance may result from __________.
mutations
However, mistakes made during DNA replication sometimes result in ___________, changes to the nucleotide sequence of DNA.
mutations
During binary fission, DNA replication begins at the _________________ and continues all the way around the circular chromosomes
origin of replication
When DNA replication is complete and the bacterium has reached twice its original size, the _________________ grows inward, diving the parent cell into two daughter cells.
plasma membrane
Gram-negative bacteria
- appear pink after Gram staining - alcohol rinse easily removes crystal violet - have a thin peptidoglycan layer - have an outer membrane as a part of their cell wall structure - have a plasma membrane
Gram-positive bacteria
- appear purple after Gram staining - alcohol rinse does not remove crystal violet - have a thick peptidoglycan layer - have a plasma membrane
The termite gut protist, Mixotricha paradoxa, has at least two kinds of bacteria attached to its outer surface. One kind is a spirochete that propels its host through the termite gut. A second type of bacteria synthesizes ATP, some of which is used by the spirochetes. The locomotion provided by the spirochetes introduces the ATP-producing bacteria to new food sources. Which term(s) is (are) applicable to the relationship between the two kinds of bacteria? 1. mutualism 2. parasitism 3. symbiosis 4. metabolic cooperation
1. mutualism 3. symbiosis 4. metabolic cooperation
The age of fossils can sometimes be determined by radiometric dating, which is based on the constant rate of decay of radioactive isotopes. The time required for half of a radioactive isotope to decay is called the half-life of that isotope. For example, the isotope carbon-14 has a half-life of 5,730 years. If a fossilized leaf contains 12.5% of the carbon-14 that was present when the fossil formed, how old is the fossil?
1.72 x 10(4th power) years
Match the numbered terms to the description that follows. Choose all appropriate terms. 1. autotroph 2. heterotroph 3. phototroph 4. chemotroph a prokaryote that obtains both energy and carbon as it decomposes dead organisms
2. heterotroph 4. chemotroph
The predatory bacterium, Bdellovibrio bacteriophorus, drills into a prey bacterium and, once inside, digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm? 1. membrane composed mostly of lipopolysaccharide 2. membrane composed mostly of phospholipids 3. peptidoglycan 4. capsule
4, 1, 3, 2
Prokaryotic ribosomes differ from those present in eukaryotic cytosol. Because of this, which of the following is correct? a) Some antibiotics can block protein synthesis in bacteria without effects in the eukaryotic host. b) Prokaryotes are unable to use a greater variety of molecules as food sources than can eukaryotes. c) Some antibiotics can block the synthesis of peptidoglycan in the walls of bacteria. d) Translation can occur at the same time as transcription in eukaryotes but not in prokaryotes. e) Eukaryotes did not evolve from prokaryotes.
a) Some antibiotics can block protein synthesis in bacteria without effects in the eukaryotic host.
From what you should now know about bacterial taxis and nodule formation, predict how a Rhizobium would respond to a flavonoid. a) The bacterium would exhibit positive chemotaxis. b) The bacterium would exhibit negative chemotaxis. c) The bacterium would exhibit negative phototaxis. d) The bacterium would exhibit positive phototaxis.
a) The bacterium would exhibit positive chemotaxis.
Hospitals can serve as sources of infections. Many of these infections are especially difficult to treat because hospital bacterial strains are often very resistant to antibiotics. Which of the following might explain the high incidence of antibiotic resistance in hospital bacterial strains? a) The high level of use of antibiotics in hospitals. b) Mutations don't occur. c) Hospital bacteria do not interact with one another. d) The high rate of meiotic recombination.
a) The high level of use of antibiotics in hospitals.
True or false? Data showing that the Bacteria were the first lineage to diverge from the common ancestor of all living organisms suggest that the Archaea and Eukarya are more closely related to each other than they are to the Bacteria. a) True b) False
a) True
True or false? Enzymes in the digestive tract catalyze hydrolysis reactions. a) True b) False
a) True
In the genetic-exchange process of transformation a) bacteria acquire DNA from their surroundings. b) a bacterium inserts DNA into another bacterium. c) a phage infects a bacterium. d) an F ("female") bacterium becomes F+ ("male").
a) bacteria acquire DNA from their surroundings.
Although not present in all bacteria, this cell covering often enables cells that possess it to resist the defenses of host organisms, especially their phagocytic cells. a) capsule b) sex pilus c) cell wall d) endospore
a) capsule
The large diversity of shapes of biological molecules is possible because of the extensive presence of _____ in the molecules. a) carbon b) sulfur c) oxygen d) nitrogen
a) carbon
The large diversity of shapes of biological molecules is possible because of the extensive presence of _____ in the molecules. a) carbon b) sulfur c) oxygen d) nitrogen e) hydrogen
a) carbon
Bacteria with flagella can change direction by _____________. a) changing the rotation direction of their flagella b) dividing in half c) gliding d) muscle contractions
a) changing the rotation direction of their flagella
An organism that uses chemicals from the environment as an energy source is a ____________. a) chemotroph b) phototroph c) autotroph
a) chemotroph
Imagine there is a species-specific fishing regulation that mandates only adult fish of this species that are 75 cm or longer may be kept and shorter fish must be released. Based on your knowledge of natural selection, you would predict that the average length of the adult fish population will a) decline. b) increase. c) remain unchanged.
a) decline.
In the case study for Tutorial #1, you learned about the "Evolution Canyons" that exist in the mountains of Israel. Singaravelan et al (2010) investigated how the melanin content of the hair of spiny mice (Acomys cahirinus) has evolved in response to alternative selection pressures inflicted by contrasting colored habitats of Evolution Canyon I (ECI). The results of this study show that spiny mice that live on the African slope of ECI have a) higher pheomelanin than eumelanin content in their hair. b) lower pheomelanin than eumelanin content in their hair. c) coloration that is the same as spiny mice living on the European slope. d) darker hair than their counterparts on the European slope.
a) higher pheomelanin than eumelanin content in their hair
The secondary structure of a protein results from _____. a) hydrogen bonds b) peptide bonds c) ionic bonds d) hydrophobic interactions e) bonds between sulfur atoms
a) hydrogen bonds
Natural selection _______________________. a) is the process by which a population becomes more well adapted to its' environment over time b) is the same as evolution c) only took place a long time ago d) is the only evolutionary process
a) is the process by which a population becomes more well adapted to its' environment over time
Prokaryotes' essential genetic information is located in the a) nucleoid. b) plasmids. c) capsule. d) nucleolus. e) nucleus.
a) nucleoid.
Amino acids are joined by _________. a) peptide bonds b) hydrogen bonds c) ionic bonds d) van der Waals interactions
a) peptide bonds
Tertiary structure is NOT directly dependent on _____. a) peptide bonds b) bonds between sulfur atoms c) hydrogen bonds d) ionic bonds e) hydrophobic interactions
a) peptide bonds
Prokaryotes (and eukaryotes) that exhibit taxis typically respond to some environmental cue. If the cue is a chemical, such as a carbon source, then the organism typically responds in a positive manner and moves toward the source in a response referred to as positive chemotaxis. Conversely, if the chemical is noxious, then the organism typically responds in a negative manner and moves away from the source in a process known as negative chemotaxis. Other environmental cues are also used (e.g., light, gravity, and magnetism). A motile bacterium that moves toward light is displaying ____________. a) positive phototaxis b) positive chemotaxis c) negative geotaxis d) negative phototaxis
a) positive phototaxis
All of the following are functions of proteins EXCEPT _____________. a) storage of genetic information b) skin coloration c) digestion d) oxygen transport
a) storage of genetic information
There are _________ amino acids that are used by organisms for protein synthesis. a) 10 b) 20 c) 30 d) 5
b) 20
In a hypothetical situation, the genes for sex pilus construction and for tetracycline resistance are located together on the same plasmid within a particular bacterium. If this bacterium readily performs conjugation involving a copy of this plasmid, then the result should be a) the rapid spread of tetracycline resistance to other bacteria in that habitat. b) a bacterium that has undergone transduction. c) the subsequent loss of tetracycline resistance from this bacterium. d) the production of endospores among the bacterium's progeny. e) the temporary possession by this bacterium of a completely diploid genome.
a) the rapid spread of tetracycline resistance to other bacteria in that habitat.
Bioremediation is _____. a) the use of organisms to remove pollutants from the environment b) the modification of prokaryotes for industrial purposes c) the use of prokaryotes in producing transgenic organisms d) the use of prokaryotes in producing pharmaceutical products e) the use of biological processes to remedy diseases
a) the use of organisms to remove pollutants from the environment
Which property of water allows dogs to cool themselves by panting? a) water's high heat of vaporization b) water's high surface tension c) the formation of covalent bonds between water molecules
a) water's high heat of vaporization
Antibiotics may not kill bacteria with genes for ___________.
antibiotic resistance
Serious bacterial infections are treated with _________.
antibiotics
Binary fission is a form of ______________ because a single individual is the sole parent and passes copies of all its genes to its offspring
asexual reproduction
The available astronomical data indicate that the universe is about ______. a) 1 billion years old b) 13 billion years old c) 4.6 billion years old d) 30 billion years old
b) 13 billion years old
Azotobacter is a genus of bacteria that live in soil and have the following characteristics: -They are bacilli. -They are gram-negative. -They are obligate aerobes. -They can fix nitrogen. (Unlike some other nitrogen-fixing - bacteria, which associate with the roots of plants, Azotobacter species are free-living.) Select the four statements that are true for bacteria in the genus Azotobacter. a) They have the appearance of coils or corkscrews. b) They are shaped like rods. c) They are poisoned by O2. d) They require amino acids or other organic molecules as a source of nitrogen. e) They can convert atmospheric nitrogen to ammonia. f) They appear purple after Gram staining. g) They can carry out anaerobic respiration in an environment that lacks O2. h) They have a relatively thin layer of peptidoglycan in their cell wall. i) They use O2.
b) They are shaped like rods. e) They can convert atmospheric nitrogen to ammonia. h) They have a relatively thin layer of peptidoglycan in their cell wall. i) They use O2.
The available scientific data indicates that life first arose ______________. a) 500 million years ago b) about 3.7 billion years ago c) less than 10,000 years ago d) about 3.7 million years ago
b) about 3.7 billion years ago
Prokaryotes convert atmospheric nitrogen to the biologically available compound __________ in a process known as nitrogen fixation. a) amino acids b) ammonia c) protein d) nucleic acids
b) ammonia
In which of the following local environments would an extremophile (an archaea) most likely be found? a) your socks b) an acidic settling pond near an old coal mine c) stinky cheese d) a flowing mountain stream
b) an acidic settling pond near an old coal mine
Some bacteria can withstand harsh conditions by forming _______________. a) peptidoglycans b) an endospore c) a pilus d) a capsule
b) an endospore
The bacterium Streptococcus mutans lives on our teeth, and in the presence of excess sugar can cause tooth decay. S. mutans is __________________. A, a host a) an exotoxin b) an opportunistic pathogen c) a commensal.
b) an opportunistic pathogen
Which of these individuals is likely to be most successful in an evolutionary sense? a) an organism that lives 100 years and leaves two offspring, both of whom survive to reproduce b) an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce c) a reproductively sterile individual who never falls ill d) a male who mates with 20 females and fathers one offspring e) a female who mates with 20 males and produces one offspring that lives to reproduce
b) an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce
Prokaryotes reproduce by ___________________________. a) transformation b) binary fission c) conjugation d) transduction
b) binary fission
An example of catabolism is the _________________. a) removal of water from a peptide bond b) breakdown of starch into simple sugars c) production of testosterone d) synthesis of DNA from nucleotide bases
b) breakdown of starch into simple sugars
Yersinia pestis is the causative agent in which of the following diseases? a) cholera b) bubonic plague c) bacterial dysentery d) diphtheria
b) bubonic plague
You isolate a strain of bacteria and find that it obtains its carbon from carbon dioxide and its energy from complex carbon. It can be categorized as a ___________. a) chemoheterotroph b) chemoautotroph c) photoautotroph d) photoheterotroph
b) chemoautotroph
Palm oil and coconut oil are more like animal fats than are other plant oils, and are usually solid at room temperature. This is because they _____ than other plant oils. contain more sodium a) contain more C to C double bonds b) contain fewer C to C double bonds c) are less soluble in water d) contain fewer hydrogen atoms
b) contain fewer C to C double bonds
A saprobe is an organism that ________. a) converts nitrogen to ammonia b) lives off decaying matter c) converts carbon dioxide to sugars d) undergoes anaerobic metabolism
b) lives off decaying matter
The relationship between a legume and bacteria in its root nodules is best described as ________________. a) predatory b) mutualism c) parasitism d) commensalism
b) mutualism
Which of the following features can be used to distinguish bacteria from archaea? a) their small size b) one has genes that appear more eukaryotic in character c) possession of a membrane-bound nucleus d) possession of less DNA
b) one has genes that appear more eukaryotic in character
The unequal sharing of electrons within a water molecule makes the water molecule _____. a) hydrophobic b) polar c) ionic d) have a low surface tension e) change easily from a liquid to gaseous form
b) polar
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by a) hydrogen bonds. b) polar covalent bonds. c) nonpolar covalent bonds. d) ionic bonds.
b) polar covalent bonds.
The complexity and variety of organic molecules is due to a) their interaction with water. b) the chemical versatility of carbon atoms. c) the fact that they can be synthesized only in living organisms. d) their tremendously large sizes. e) the variety of rare elements in organic molecules.
b) the chemical versatility of carbon atoms.
Prokaryotes that are gram-negative _________________. a) are not very resistant to antibiotics b) typically have little peptidoglycan c) typically have simple cell walls d) have a single membrane around the cell
b) typically have little peptidoglycan
The diversity of carbon compounds is largely due to carbon's ________________. a) hydrophilicity b) valence of four c) large positive charge d) full outer electron shell
b) valence of four
A phage is a ________________. a) mutant bacterium b) virus that infects a bacterium c) fertility factor d) piece of bacterial DNA
b) virus that infects a bacterium
Which property of water allows a water strider to walk on water? a) the formation of covalent bonds between water molecules b) water's high surface tension c) adhesion of water molecules to other kinds of molecules
b) water's high surface tension
The universal genetic language of DNA is common to virtually all organisms on Earth, however diverse. What is the best explanation for this fact? a) The universal nature of the genetic language of DNA is due to coincidence. b) The universal genetic language is explained by the chemistry of DNA and proteins. c) All living things share a common genetic language of DNA because they share a common ancestry.
c) All living things share a common genetic language of DNA because they share a common ancestry.
If two molecules of glucose (C6H12O6) are joined via condensation synthesis, the resulting molecule would have a molecular formula of _______________. a) C12H25O13 b) C12H24O12 c) C12H22O11 d) C6H12O6
c) C12H22O11
Which part of an amino acid is always acidic? a) Amino functional group b) Side chain ("R group") c) Carboxyl functional group d) None of the above
c) Carboxyl functional group
A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. What should be true of the cell wall of this bacterium? a) After it has been subjected to Gram staining, the cell should remain purple. b) Its innermost layer is composed of a phospholipid bilayer. c) It has an outer membrane of lipopolysaccharide. d) It has a relatively large amount of peptidoglycan.
c) It has an outer membrane of lipopolysaccharide.
Which of the following statements about natural selection is most accurate? a) Mammals in cold climates need warm fur so they evolve thick coats. b) Natural selection results in organisms that are perfectly adapted to their environment. c) Natural selection can only act on populations with genetic variation. d) Natural selection is a random process.
c) Natural selection can only act on populations with genetic variation.
The Exxon Valdez oil tanker ran aground in Alaska's Prince William Sound in the spring of 1989, dumping approximately 11-million gallons of oil. Many species of prokaryotes are known to exist in Alaska's Prince William Sound, and together they are capable of degrading petroleum and its by-products. However, in this disaster the number of organisms was insufficient to process the large amount of oil spilled. There was plenty of carbon available, but other necessary components were lacking. How was this limitation overcome? a) Antibiotics were added to the water. b) Dry ice was added to the water. c) Sugar was added to the contaminated water. d) Fertilizer was added to the water.
c) Sugar was added to the contaminated water.
Why isn't this insect drowning? a) The insect is very light. b) The insect is flying just above the water surface. c) Surface tension. d) It is difficult to change the temperature of water. e) The insect is swimming.
c) Surface tension.
Sweat plays an important role in thermoregulation due to the high heat of vaporization of water. That is, it takes energy to not only raise the temperature of water, but additional energy is required to make the phase change from water to gas. In individuals with HED (hypohidrotic ectodermal dysplasia), sweat gland numbers are reduced. Predictably, what symptoms occur in HED-affected individuals? a) They would have excessive body odor. b) They would always be thirsty. c) They would be prone to heat stroke. d) There would be no symptoms associated with this condition.
c) They would be prone to heat stroke.
Which of the following processes contributes to genetic recombination in prokaryotes? a) Meiosis b) Mutation c) Transduction
c) Transduction
Which property of water allows a paper towel to pick up a puddle of water? a) water's high surface tension b) water's high heat of vaporization c) adhesion of water molecules to other kinds of molecules
c) adhesion of water molecules to other kinds of molecules
Cholera can kill quickly. Based on the action of cholera toxin and the first principles of osmosis, what is the most deadly symptom of cholera infection? a) excessive urine production b) bloating c) excessive diarrhea d) loss of blood
c) excessive diarrhea
The characteristic that all lipids have in common is that _____. a) they all contain nitrogen b) they do not have a high energy content c) none of them dissolves in water d) they are all acidic when mixed with water e) they are all made of fatty acids and glycerol
c) none of them dissolves in water
According to the evidence for the early chemical evolution of life, the atmosphere on early Earth was highly reductive because it was lacking which of the following key molecules? a) nitrogen b) neon c) oxygen d) carbon dioxide
c) oxygen
RNA's nitrogenous bases include ____________. a) guanine and thymine b) uracil and thymine c) uracil and guanine d) none of these choices
c) uracil and guanine
Which of the following is (are) true of natural selection? a) It results in descent with modification. b) It requires genetic variation. c) It results in descent with modification and involves differential reproductive success. d) It requires genetic variation, results in descent with modification, and involves differential reproductive success. e) It involves differential reproductive success.
d) It requires genetic variation, results in descent with modification, and involves differential reproductive success.
What is lateral gene transfer? a) Inheritance of a gene through meiosis b) Inheritance of a gene from a parent c) Inheritance of a gene through mitosis d) Physical transfer of a gene from a species in one lineage to a species in another lineage.
d) Physical transfer of a gene from a species in one lineage to a species in another lineage.
Which polymers are composed of amino acids? a) Monomers b) Nucleic acids c) Carbohydrates d) Proteins
d) Proteins
___________ is(are) the best source of fossils. a) Igneous rock b) Lava c) Glaciers d) Sedimentary rock
d) Sedimentary rock
Geologists have used multiple types of evidence to infer the existence of Pangaea and the role of plate tectonics in Earth's history. Which of the following DOES NOT provide evidence for the movement of continents? a) Fossils of the same organism, such as the Jurassic reptile Cynognathus, are found in both South America and Africa. b) The presence of fossils from tropical plant species in Antarctica. c) The appearance of the continents today - the coastlines of western Africa and eastern South America could fit together. d) The presence of sharks in the coastal waters of Australia and Africa.
d) The presence of sharks in the coastal waters of Australia and Africa.
Which of the following is true of both starch and cellulose? a) They are both structural components of the plant cell wall. b) They are both used for energy storage in plants. c) They can both be digested by humans. d) They are both polymers of glucose.
d) They are both polymers of glucose.
Proteins are polymers of _____. a) CH2O units b) nucleotides c) glycerol d) amino acids e) hydrocarbons
d) amino acids
Penn State turf scientists studying the role of synthetic turf in systemic infections with the bacterium Staphylococcus aureus concluded that: a) S. aureus is found at high levels on synthetic turf and is not easily killed by disinfecting the turf. b) there is a high risk of contracting S. aureus from natural turf surfaces but not from synthetic turf surfaces because bacteria, including S. aureus, are much more abundant on natural turf. c) S. aureus is naturally found at high levels on synthetic turf, but it is quickly killed by the UV radiation from sunlight. d) an increased risk of contracting S. aureus could be caused by the abrasions received while playing on synthetic turf, which would allow the bacteria on the skin or equipment to enter the body.
d) an increased risk of contracting S. aureus could be caused by the abrasions received while playing on synthetic turf, which would allow the bacteria on the skin or equipment to enter the body.
Many of water's emergent properties, such as its cohesion, its high specific heat, and its high heat of vaporization, result from the fact that water molecules _____. a) are in constant motion b) are extremely large c) tend to repel each other d) are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively e) are very small
d) are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively
Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are _____. a) photoautotrophs b) chemoheterotrophs c) photoheterotrophs d) chemoautotrophs
d) chemoautotrophs
About 10% (or more) of us carry Stapylococcus aureus on our skin as part of our normal flora. Upon wounding, these bacteria can invade the bloodstream and lead to a variety of diseases. This is one example of an opportunistic infection. If you are one of the 10% affected and have no disease symptoms at this time, then this symbiosis is categorized as a ________. a) predation b) mutualistic symbiosis c) parasitic symbiosis d) commensalistic symbiosis
d) commensalistic symbiosis
You are digging in a swampy area, looking for new bacteria. You dig deep into the mud where little oxygen penetrates and take a sample back to the lab for culturing. You find one species that grows in the absence of oxygen and it also grows and uses oxygen when it is available. This bacterium is a ________________. a) facultative aerobe b) an obligate aerobe c) an obligate anaerobe d) facultative anaerobe
d) facultative anaerobe
How many half-lives should have elapsed if 6.25% of the parent isotope remains in a fossil at the time of analysis? a) one b) two c) three d) four e) five
d) four
Each water molecule is joined to _____ other water molecules by ____ bonds. a) two ... polar covalent b) four ... polar covalent c) three ... ionic d) four ... hydrogen e) two ... hydrogen
d) four ... hydrogen
Lipids are predominantly hydrophobic because of their ______________. a) sugar-phosphate backbone b) nitrogenous bases c) phosphate groups d) hydrocarbon chains
d) hydrocarbon chains
The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases. a) S—S bonds b) hydrophilic interactions c) ionic bonds d) hydrogen bonds e) covalent bonds
d) hydrogen bonds
The building blocks or monomers of nucleic acid molecules are called _____. a) pyrimidines and purines b) fatty acids c) DNA and RNA d) nucleotides e) polysaccharides
d) nucleotides
What type of bond joins the monomers in a protein's primary structure? a) S - S b) hydrogen c) hydrophobic d) peptide e) ionic
d) peptide
Eubacterial cell walls differ from eukaryotes' cell walls in that they have _____________________. a) flagella b) much less DNA c) photosynthetic compounds d) peptidoglycan
d) peptidoglycan
Dendrochronology is especially useful when estimating _________. a) climate conditions on early Earth b) the time of the last ice age c) the age of microbes living in the Antarctic ice. d) relatively recent climate patterns
d) relatively recent climate patterns
