BIO 110 Exam 1 (tutorials 1-6)
Which of the following is not attached to the central carbon atom in an amino acid? A side chain ("R group") An amino functional group A carboxyl functional group An oxygen
An oxygen
Prokaryotic life was present at least _________________ years ago. 1 billion 3 billion 1 million - 10 million 100 million
3 billion
If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand? 3'-UAAACG-5' 3'-GCAAAT-5' 3'-TAAACG-5' 3'-ATTTGC-5' 3'-TUUUCG-5'
3'-TAAACG-5'
Approximately how far back in time does the fossil record extend? 6,000,000 years 3,500,000 years 6,000 years 3,500,000,000 years 5,000,000,000,000 years
3,500,000,000 years
If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain? 75 50 150 25 200
75
Which of the following statements about the formation of polypeptides from amino acids is true? A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. The reaction occurs through the addition of a water molecule to the amino acids. Polypeptides form by condensation or hydrolysis reactions. A bond can form between any carbon and nitrogen atom in the two amino acids being joined.
A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.
Water is a source of ______________ for chemical reactions in cells. (a) hydrogen atoms (b) oxygen atoms (c) energy Both (a) and (b) (a), (b), and (c).
Both (a) and (b)
Which factor is important in making it possible to cool yourself by sweating? Think carefully! (a) Molecules collide with varied angles and speeds. (b) Hydrogen bonds are relatively weak. (c) Water has more energy at the body surface. Both (a) and (b). (a), (b), and (c).
Both (a) and (b).
Which statement helps to explain why ice is less dense than liquid water? (a) Water molecules make hydrogen bonds at definite angles. (b) Cold molecules move less than warm molecules. (c) Hydrogen bonds lengthen in the cold. All of the above. Both (a) and (b).
Both (a) and (b).
If two molecules of glucose (C6H12O6) are joined via condensation synthesis, the resulting molecule would have a molecular formula of _______________. C12H25O13 C12H24O12 C12H22O11 C6H12O6
C12H22O11
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions? C18H30O15 C6H10O5 C18H36O18 C18H32O16
C18H32O16
Which of the following hydrocarbons has a double bond in its carbon skeleton? C2H4 C2H6 C3H8 CH4 C2H2
C2H4
Which part of an amino acid is always acidic? Side chain ("R group") Carboxyl functional group Amino functional group None of the above
Carboxyl functional group
There are four levels of protein structure. These figures show primary, secondary, tertiary, and quaternary protein structure. Which level(s) of protein structure may be stabilized by covalent bonds? None of the levels of protein structure is stabilized by covalent bonds. Primary, tertiary and quaternary levels of protein structure Secondary level of protein structure
Primary, tertiary and quaternary levels of protein structure
Carbon-14 dating works for fossils up to about 75,000 years old. Most dinosaurs went extinct 65.5 million years ago. Can 14C be used to date dinosaur bones? No, 14C can only be used to date dinosaur teeth, which are much stronger than bones. No, the 14C present in the dinosaur when it died would decay too much to be measured after 65.5 million years. Yes, the bones contained 14C when the dinosaur died so it can be measured to determine the fossil's age. Yes, the bones continued to take in 14C, even after the dinosaur died.
No, the 14C present in the dinosaur when it died would decay too much to be measured after 65.5 million years.
___________ is(are) the best source of fossils. Igneous rock Lava Glaciers Sedimentary rock
Sedimentary rock
Why isn't this insect drowning? The insect is flying just above the water surface. Surface tension. The insect is swimming. It is difficult to change the temperature of water. The insect is very light.
Surface tension
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? The high level of use of antibiotics in hospitals. Mutations don't occur. Hospital bacteria do not interact with one another. The high rate of meiotic recombination.
The high level of use of antibiotics in hospitals.
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? They would have excessive body odor. They would always be thirsty. They would be prone to heat stroke. There would be no symptoms associated with this condition.
They would be prone to heat stroke.
Dissolving is best described as ... molecules breaking into ions. a change from a solid to a liquid. a separation of molecules into neutral atoms. a mingling of molecules and/or ions. breaking covalent bonds.
a mingling of molecules and/or ions.
Glycogen is _____. a polysaccharide found in plant cell walls a polysaccharide found in animals a transport protein that carries oxygen a source of saturated fat the form in which plants store sugars
a polysaccharide found in animals
The available scientific data indicates that life first arose ______________. 500 million years ago about 3.7 billion years ago less than 10,000 years ago about 3.7 million years ago
about 3.7 billion years ago
Which property of water allows a paper towel to pick up a puddle of water? water's high surface tension adhesion of water molecules to other kinds of molecules water's high heat of vaporization
adhesion of water molecules to other kinds of molecules
In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits ________. altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered only altered primary structure only altered tertiary structure only altered quaternary structure
altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered
Prokaryotes convert atmospheric nitrogen to the biologically available compound __________ in a process known as nitrogen fixation. amino acids ammonia protein nucleic acids
ammonia
Some bacteria can withstand harsh conditions by forming _______________. peptidoglycans an endospore a pilus a capsule
an endospore
Which of these individuals is likely to be most successful in an evolutionary sense? a male who mates with 20 females and fathers one offspring. a female who mates with 20 males and produces one offspring that lives to reproduce. an organism that lives 100 years and leaves two offspring, both of whom survive to reproduce. a reproductively sterile individual who never falls ill. an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce.
an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce
A function of cholesterol that does not harm health is its role _____. as the primary female sex hormone the most abundant male sex hormone All of cholesterol's effects cause the body harm. as a component of animal cell membranes in calcium and phosphate metabolism
as a component of animal cell membranes
Which of the following is a major difference between RNA and DNA? type of purines type of glycosidic bond type of sugar type of phosphate
type of sugar
Prokaryotes that are gram-negative _________________. are not very resistant to antibiotics typically have little peptidoglycan typically have simple cell walls have a single membrane around the cell
typically have little peptidoglycan
RNA's nitrogenous bases include ____________. guanine and thymine uracil and thymine uracil and guanine none of these choices
uracil and guanine
A phage is a ________________. mutant bacterium virus that infects a bacterium fertility factor piece of bacterial DNA
virus that infects a bacterium
Which property of water allows dogs to cool themselves by panting? water's high heat of vaporization water's high surface tension the formation of covalent bonds between water molecules
water's high heat of vaporization
Which property of water allows a water strider to walk on water? adhesion of water molecules to other kinds of molecules the formation of covalent bonds between water molecules water's high surface tension
water's high surface tension
In the genetic-exchange process of transformation bacteria acquire DNA from their surroundings. a bacterium inserts DNA into another bacterium. a phage infects a bacterium. an F ("female") bacterium becomes F+ ("male").
bacteria acquire DNA from their surroundings.
An example of catabolism is the _________________. removal of water from a peptide bond. breakdown of starch into simple sugars. production of testosterone. synthesis of DNA from nucleotide bases.
breakdown of starch into simple sugars
The large diversity of shapes of biological molecules is possible because of the extensive presence of _____ in the molecules. oxygen carbon sulfur nitrogen hydrogen
carbon
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 ___________. chemoheterotroph chemoautotroph photoautotroph photoheterotroph
chemoautotroph
An organism that uses chemicals from the environment as an energy source is a ____________. chemotroph phototroph autotroph
chemotroph
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 ________. predation mutualistic symbiosis parasitic symbiosis commensalistic symbiosis
commensalistic symbiosis
In the case study for Tutorial #1, you learned about the "Evolution Canyons" that are found in a mountain chain in Israel. Singaravelan et al (2010) investigated how the melanin content of the hair of spiny mice (Acomys cahirinus) has evolved in response to the selection pressures of the different environments of the north and south-facing slopes of Evolution Canyon I (ECI). The results of this study show that spiny mice that live on the south-facing slope of ECI have higher pheomelanin than eumelanin content in their hair. lower pheomelanin than eumelanin content in their hair. coloration that is the same as spiny mice living on the north-facing slope. darker hair than their counterparts on the north-facing slope.
higher pheomelanin than eumelanin content in their hair.
Lipids are predominantly hydrophobic because of their ______________. sugar-phosphate backbone nitrogenous bases phosphate groups hydrocarbon chains
hydrocarbon chains
The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases. covalent bonds hydrogen bonds S—S bonds hydrophilic interactions ionic bonds
hydrogen bonds
Water molecules have a polarity, which allows them to be electrically attracted to other water molecules and other polar molecules by weak chemical bonds known as _____. polar covalent bonds Van der Waals interactions nonpolar covalent bonds hydrogen bonds ionic bonds
hydrogen bonds
Water has surface tension because ... molecules at the surface make more hydrogen bonds. hydrogen bonds between surface water molecules resist being stretched. cohesion forces are weaker at the surface. there is positive pressure inside the water mass. water tends to evaporate from the surface.
hydrogen bonds between surface water molecules resist being stretched.
What holds phospholipids together in a bilayer formation? ionic interactions between phospholipid tails interaction of cis-double bonds in tails with polar heads hydrophilic and hydrophobic interactions with water covalent bonds between polar heads
hydrophilic and hydrophobic interactions with water
A saprobe is an organism that ________. converts nitrogen to ammonia lives off decaying matter converts carbon dioxide to sugars undergoes anaerobic metabolism
lives off decaying matter
glucose + glucose —> _____ by _____. sucrose + water ... dehydration synthesis starch + water ... dehydration synthesis cellulose + water ... hydrolysis lactose + water ... hydrolysis maltose + water ... dehydration synthesis
maltose + water ... dehydration synthesis
Which of these is a source of lactose? starch potatoes milk sugar cane sugar beets
milk
The relationship between a legume and bacteria in its root nodules is best described as ________________. predatory mutualism parasitism commensalism
mutualism
Which of the following statements about natural selection is most accurate? Natural selection can only act on populations with genetic variation. Natural selection results in organisms that are perfectly adapted to their environment. Mammals in cold climates need warm fur so they evolve thick coats. Natural selection is a random process.
natural selection can only act on populations with genetic variation
The building blocks or monomers of nucleic acid molecules are called _____. See Concept 5.5 (Page 84) nucleotides pyrimidines and purines DNA and RNA fatty acids polysaccharides
nucleotides
Eubacterial cell walls differ from eukaryotes' cell walls in that they have _____________________. flagella much less DNA photosynthetic compounds peptidoglycan
peptidoglycan
A nucleotide is composed of a(n) _____. glycerol, a nitrogen-containing base, and a five-carbon sugar amino group, a nitrogen-containing base, and a five-carbon sugar phosphate group, a nitrogen-containing base, and a hydrocarbon phosphate group, a nitrogen-containing base, and a five-carbon sugar sulfhydryl group, a nitrogen-containing base, and a five-carbon suga
phosphate group, a nitrogen-containing base, and a five-carbon sugar
The unequal sharing of electrons within a water molecule makes the water molecule _____. hydrophobic have a low surface tension polar change easily from a liquid to gaseous form ionic
polar
In this molecule, what type of bond is found between the oxygen and hydrogens? ionic nonpolar covalent hydrophobic polar covalent hydrophilic
polar covalent
Dendrochronology is especially useful when estimating _________. climate conditions on early Earth. the time of the last ice age. the age of microbes living in the Antarctic ice. relatively recent climate patterns.
relatively recent climate patterns
A coccus bacterium, such as Streptococcus pneunoniae, would be ________________. rod-shaped fuzzy helical round
round
All of the following are functions of proteins EXCEPT _____________. storage of genetic information skin coloration digestion oxygen transport
storage of genetic information
Radiocarbon dating is appropriate to use when estimating the dates of fossils deposited at the time of _________. the diversification of bony fishes (363 - 409 million years ago) the origin of most modern animal phyla (510 - 570 million years ago) the time at which life forms arose on Earth the first European occupation of the New World (less than 10,000 years ago)
the first European occupation of the New World (less than 10,000 years ago)
Which statement must be mentioned in explaining why amphipathic molecules line up at a water surface? Polar groups repel water. Nonpolar groups repel water. Polar groups attract one another. Nonpolar groups attract one another. All of the above.
Polar groups attract one another.
____________ is when organisms of different species both benefit by living intimately for extended periods of time. Mutualism Parasitism Predation Commensalism
Mutualism
True or false? Enzymes in the digestive tract catalyze hydrolysis reactions. True False
True
The tendency of an atom to pull electrons toward itself is referred to as its _____. covalency ionic potential polarity electronegativity tonicity
electronegativity
How many half-lives should have elapsed if 6.25% of the parent isotope remains in a fossil at the time of analysis? one two three four five
four
Each water molecule is joined to _____ other water molecules by ____ bonds. two ... polar covalent four ... polar covalent three ... ionic four ... hydrogen two ... hydrogen
four ... hydrogen
Use the following information to answer the question. "The native structure of hemoglobin (Hb) comprises of two α and two β subunits, each of which carries a heme group. There appear to be no previous studies that report the in-vitro folding and assembly of Hb from highly unfolded α and β globin in a 'one-pot' reaction. One difficulty that has to be overcome for studies of this kind is the tendency of Hb to aggregate during refolding. This work demonstrates that denaturation of Hb in 40% acetonitrile at pH 10.0 is reversible." (J Am Soc Mass Spectrum 2007, 18, 8-16) Hemoglobin, when subjected to 40% acetonitrile at pH 10.0, loses its quaternary structure, which means the ________. four α and β polypeptides dissociate peptide bonds between amino acids break α and β polypeptides lose their 3-D structure four α and β polypeptides dissociate, peptide bonds between amino acids, and α and β polypeptides lose their 3-D structure
four α and β polypeptides dissociate
Though you add heat, the temperature of boiling water remains constant because ... it takes energy to break hydrogen bonds. it takes energy to break covalent bonds. it takes energy to circulate water. water has a constant boiling temperature. None of the above. The temperature rises during boiling.
it takes energy to break hydrogen bonds.
Which of these does NOT contain a structural protein? tendons ligaments spider silk ovalbumin muscles
ovalbumin
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? nitrogen. neon. oxygen. carbon dioxide.
oxygen
Which of the following helps most to explain why water has a high specific heat? (a) A water molecule can make 4 hydrogen bonds. (b) The water molecule has exceptionally strong covalent bonds. (c) Water temperature is exceptionally sensitive to heat. Both (a) and (b). Both (b) and (c).
(a) A water molecule can make 4 hydrogen bonds.
The open spaces in water's crystal structure make it possible for ... (a) aquatic life to exist at the North Pole. (b) water to have a low boiling point. (c) life to occur in hot springs. Both (b) and (c). (a), (b), and (c).
(a) aquatic life to exist at the North Pole.
Which statement is true of water's tensile strength? (a) It results from hydrogen bonding. (b) It helps to pull water through plants. (c) It involves both cohesion and adhesion. Both (a) and (b). (a), (b), and (c).
(a), (b), and (c).
Why doesn't oil mix with water? (a) Nonpolar molecules repel water molecules. (b) Polar molecules repel nonpolar molecules. (c) Polar molecules attract one another. (d) Nonpolar molecules attract one another. Both (a) and (d).
(c) Polar molecules attract one another.
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? 16,800 11,200 22,900 1,400 2,800
22,900
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 _____. 11,460 years old 5730 years old 2865 years old 17,190 years old
11,460 years old
Use the following information to answer the question. "The native structure of hemoglobin (Hb) comprises of two α and two β subunits, each of which carries a heme group. There appear to be no previous studies that report the in-vitro folding and assembly of Hb from highly unfolded α and β globin in a 'one-pot' reaction. One difficulty that has to be overcome for studies of this kind is the tendency of Hb to aggregate during refolding. This work demonstrates that denaturation of Hb in 40% acetonitrile at pH 10.0 is reversible." (J Am Soc Mass Spectrum 2007, 18, 8-16) How many heme groups are present in three hemoglobin protein molecules? 12 3 4 9
12
The available astronomical data indicate that the universe is about ______. 1 billion years old 13 billion years old 4.6 billion years old 30 billion years old
13 billion years old
How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule? 20 10 40 19
19
How many fatty acids are in a phospholipid?
2
There are _________ amino acids that are used by organisms for protein synthesis. 10 20 30 5
20
Which molecule is less soluble in water--a fat or a phospholipid? Why? A fat molecule is less soluble in water because it has more carbons and hydrogens than a phospholipid. A fat molecule is less soluble in water because it has three non-polar fatty acids and no polar or charged head like a phospholipid has. A phospholipid is less soluble in water because it is smaller than a fat molecule. A phospholipid is less soluble in water because even though it has one end that is hydrophilic, the end that is hydrophobic is larger.
A fat molecule is less soluble in water because it has three non-polar fatty acids and no polar or charged head like a phospholipid has.
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? About 50% About 25% About 12.5% About 75%
About 50%
Carbon-14 decays into ____________. Lithium-7 Nitrogen-14 Carbon-13 Carbon-12
Nitrogen-14
Which monomers make up RNA? Nucleotides Simple sugars Polymers Amino acids
Nucleotides
Which polymers are composed of amino acids? Carbohydrates Nucleic acids Proteins Monomers
Proteins
Which level of protein structure is characteristic of some, but not all, proteins? Quaternary level of protein structure Tertiary level of protein structure Secondary level of protein structure
Quaternary level of protein structure
If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? both DNA and RNA RNA DNA polypeptides
RNA
Which of these is NOT a lipid? phospholipid steroids cholesterol wax RNA
RNA
Radioactive uranium-235 has a half-life of 704 million years. If it was incorporated into dinosaur bones, could it be used to date the dinosaur fossils? No, the dinosaurs went extinct too recently to use a radioisotope with a half-life of 704 million years. Yes, after 65.5 million years only about one tenth of the 235U would have decayed, leaving plenty to measure in the fossils. No, only about one tenth of the 235U would have decayed after 65.5 million years, not leaving enough to measure in the fossils. Yes, but only for dinosaurs that lived more than 704 million years ago.
Yes, after 65.5 million years only about one tenth of the 235U would have decayed, leaving plenty to measure in the fossils.
Use the following information to answer the question. "The native structure of hemoglobin (Hb) comprises of two α and two β subunits, each of which carries a heme group. There appear to be no previous studies that report the in-vitro folding and assembly of Hb from highly unfolded α and β globin in a 'one-pot' reaction. One difficulty that has to be overcome for studies of this kind is the tendency of Hb to aggregate during refolding. This work demonstrates that denaturation of Hb in 40% acetonitrile at pH 10.0 is reversible." (J Am Soc Mass Spectrum 2007, 18, 8-16) Hemoglobin is ________. a tertiary protein with four polypeptides a tertiary protein with two polypeptides a quaternary protein with four polypeptides a quaternary protein with two polypeptides
a quaternary protein with four polypeptides
Prokaryotes reproduce by ___________________________. transformation conjugation binary fission transduction
binary fission
Which of these is a polysaccharide? lactose cellulose glucose sucrose galactose
cellulose
_____ is the most abundant organic compound on Earth. Lactose Cellulose Glycogen Glucose Starch
cellulose
What process exerts the pull on water molecules that is relayed from leaf to root via cohesion? evaporation antigravity precipitation gravity
evaporation
Defensive proteins are manufactured by the _____ system. immune cardiovascular integumentary digestive nervous
immune
Natural selection _______________________. is the process by which a population becomes more well adapted to its' environment over time. is the same as evolution. only took place a long time ago. is the only evolutionary process.
is the process by which a population becomes more well adapted to its' environment over time
Which of these is rich in unsaturated fats? beef fat a fat that is solid at room temperature butter lard olive oil
olive oil
Which of the following features can be used to distinguish bacteria from archaea? their small size one has genes that appear more eukaryotic in character possession of a membrane-bound nucleus possession of less DNA
one has genes that appear more eukaryotic in character
The diversity of carbon compounds is largely due to carbon's ________________. hydrophilicity valence of four large positive charge full outer electron shell
valence of four