biol 110 world campus final old

During an archeological dig, you find an ancient scroll made of paper from papyrus. You decide to use carbon dating to determine the age of the scroll. The amount of C-14 in the scroll is approximately 25% of the amount in the scroll at the time of it's creation. What is the approximate age of the scroll? (Use a half-life of 5730 years for C-14). Correct!

11,460 years

The available astronomical data indicate that the universe is about ______.

13 billion years old

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 1/8 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 _____.

17,190 years old

There are _________ amino acids that are used by organisms for protein synthesis.

20

Prokaryotic life was present at least _________________ years ago.

3 billion

How many half-lives should have elapsed if 6.25% of the parent isotope remains in a fossil at the time of analysis?

4

The skeletal remains of a wooly mammoth, found on Wrangel Island in northern Russia, were found to have approximately 50% of their original level of C14. What is the approximate age of the mammoth's skeleton? (The half-life of C14 is 5730 years)

5730 years

You are an archeologist and you find the remains of some bones at one of your digs. You want to know how old they are so you use carbon-14 dating as a dating method. You find that the bones have about 25% the amount of carbon-14 compared to a fresh sample. The half-life of carbon-14 is 5730 years. It can be concluded that your sample is about:

8,595 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?

About 50%

Ice floats. What would be the consequence to aquatic life if ice sank?

Aquatic life would suffer in the winter

Clostridium botulinum is an anaerobic gram positive bacterium, and produces botulism toxin, one of the most potent human toxins. Endospores of this bacterium are often found in honey, and parents are advised not to feed raw honey to children under the age of two because it can lead to infant botulism. Why is it dangerous for infants to consume these endospores? Correct!

Because the endospores can sporulate in the anaerobic conditions in the human gut and produce botulinum neurotoxin, leading to paralysis.

If two molecules of glucose (C6H12O6) are joined via condensation synthesis, the resulting molecule would have a molecular formula of _______________.

C12H22O11

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking six (6) glucose molecules together by dehydration synthesis reactions?

C36H62O31

True or False? Prokaryotes have fewer metabolic modes than eukaryotes.

False because prokaryotes are able to utilize inorganic molecules for energy and eukaryotes cannot.

Which bonds must be broken for water to vaporize?

Hydrogen bonds

You have discovered a new species of prokaryote and are examining it to determine which domain it belongs to. Which of the following characteristics would place it as a member of the archaea but NOT the bacteria?

Its genes contain introns.

Which of the following statements about natural selection is most accurate?

Natural selection can only act on populations with genetic variation.

Carbon-14 decays into ____________.

Nitrogen-14

You are reading a blog written by a student who is working at an archeological dig in Cyprus. She mentions that they just uncovered an ancient burial site in which the skeletal remains of a human are found next to those of a cat. The arrangement of the bones suggests that the cat was buried with its owner and may have been a pet. Remarkably, the location of the grave relative to other known artifacts suggests it is at least 10,000 years old. If this is correct, then this is the earliest evidence for cat domestication. The blog author suggests that dendrochronological analysis of some wood fragments found nearby, together with C14 analysis should confirm the dates. You are not so sure these two methods will work equally well. Which method is most likely to shed accurate insight into the age of these two skeletons? Why?

Radiocarbon dating

___________ is(are) the best source of fossils.

Sedimentary rock

Bacteria show many types of symbiotic relationships with other organisms. Which of the following is NOT a mutualistic relationship between bacteria and another organism?

The bacterium that causes the plant disease leaf spot on a Dieffenbachia plant.

From what you should now know about bacterial taxis and nodule formation, predict how a nitrogen-fixing Rhizobium would respond to a plant flavonoid.

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 resistant to multiple 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.

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?

The presence of sharks in the coastal waters of Australia and Africa.

This question refers to the "Real Life Example" in this tutorial. Which of the following is a plausible hypothesis for why Bacillus subtilis living on the south-facing slopes of the Evolution Canyon have more efficient biosynthesis than those living on the north-facing slopes?

The south-facing slopes are a more extreme environment and efficient biosynthesis is an adaptation to this environment.

Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Which of these observations comes closest to explaining the basis for placing these organisms in different taxa, well before relevant data from molecular systematics became available?

Their cell walls are composed of different biochemicals.

Which of the following would NOT be true of a Gram (+) bacterium?

There is a phospholipid bilayer as the outside layer of the cell, surrounding the cell wall.

You are collecting biological samples and bringing them back to the lab to determine the diversity of organisms present in the sample. Most of the species are already described, but you find one that you think is a new species. It is a prokaryote. Which of the following would you find if it is a member of the Archaea, not a bacteria?

There would be introns in some of its genes.

Which statement is true about obligate anaerobes?

They are poisoned by O2.

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 be prone to heat stroke.

Which of the following is the best use of dendrochronology?

To determine climate patterns in the last 5000 years.

A bacteriologist is studying the ability of bacteria to acquire genes from other bacteria. She adds a colony of bacteria to a test tube containing a sterile solution which includes the antibiotic tetracycline (tetracycline kills bacteria). After ten generations, the colony of bacteria inside the test tube is completely resistant to tetracycline. She then kills this colony of bacteria with heat and adds tetracycline sensitive bacteria to the test tube with the dead bacteria. After a single generation, many of the tetracycline sensitive bacteria have given rise to tetracycline resistant bacteria. This is due to bacteria's ability to perform ________________________.

Transformation.

True or False. Bacterial conjugation is a form of sex.

True because all forms of sex, including conjugation, create a new combination of genetic material.

Which would be the LEAST accurate statement about the evolution of prokaryotes and the changing environment of Earth?

While prokaryotes have diverse morphologies, they basically all utilize the same nutritional mode.

You are collecting organisms from ocean vent communities and you discover an organism that has not been described before. It lacks a nucleus, has a thick layer of peptidoglycan associated with its cell membrane, and genetic analysis confirms that its genes do not contain any introns. This organism is most likely

a gram positive bacteria

What conditions are necessary for a canned food product to become tainted with botulism?

a lack of oxygen

Radiometric dating is a form of____________, and during the radioactive decay of C14, it decays to ________

absolute/N14

Thiomicrospira crunogena is a species of bacteria that is found in deep sea vents. Thiomicrospira crunogena gets its energy from hydrogen-sulfide and its carbon from CO2. It requires oxygen as an electron acceptor molecule. Thiomicrospira crunogena is therefore classified as a

aerobic chemoautotroph.

Prokaryotes convert atmospheric nitrogen to the biologically available compound __________ in a process known as nitrogen fixation.

ammonia

In which of the following local environments would an extremophile (an archaea) most likely be found?

an acidic settling pond near an old coal mine

Some bacteria can withstand harsh conditions by forming _______________

an endospore

The bacterium Streptococcus mutans lives on our teeth, and in the presence of excess sugar can cause tooth decay. S. mutans is __________________.

an opportunistic pathogen

The Earth's early atmosphere was ______________. This changed when some bacteria evolved the ability to __________, which releases oxygen.

anaerobic / photosynthesize

Natural selection describes the differential reproductive success of more fit individuals. Natural selection cannot occur without reproduction. With each reproductive generation, there is an opportunity for natural selection to occur; the shorter the generation time, the sooner beneficial traits can increase in frequency within a population. To demonstrate how much more quickly a population of bacteria can undergo natural selection than humans, take out your calculator. If a population of bacteria can reproduce in 20 minutes, estimate how many more opportunities there are for natural selection to occur when compared to a human with a generation time of 18 years?

at least 450,000

In the genetic exchange process of bacterial transformation:

bacteria acquire DNA from their surroundings

A mutation that caused a polar amino acid to appear in a protein instead of a nonpolar amino acid would predictably cause the protein to

be more hydrophilic.

Prokaryotes reproduce by _________________.

binary fission

An example of catabolism is the _________________.

breakdown of starch into simple sugars

Yersinia pestis is the causative agent in which of the following diseases?

bubonic plague

Bacteria with flagella can change direction by _____________.

changing the rotation direction of their flagella

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 ___________.

chemoautotroph

A researcher discovers a new species of bacteria that obtains both its energy and carbon from decaying organisms. This species can be categorized based upon its mode of nutrition as a

chemoheterotroph

An organism that uses chemicals from the environment as an energy source is a ____________.

chemotroph

About 10% (or more) of us carry Stapylococcus aureus on our skin as part of our normal flora. Upon wounding, this 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 ________.

commensalistic symbiosis

In the synthesis of proteins and carbohydrates, monomers are joined to form polymers by

condensation reactions that produces water molecules as a byproduct

A colony of antibiotic-resistant bacteria is mixed with a colony of antibiotic-sensitive bacteria. After a few days, all of the bacteria are resistant to the antibiotic. Which of these is most likely to result in this rapid spread of resistance in a bacterial population?

conjugation

In the bacteria E. coli, some mutant individuals lack the ability to synthesize the vitamin biotin. For these individuals to grow, their medium must be supplemented with biotin. However, when these nutritional mutants are mixed with individuals that can synthesize biotin and form a pilus, some of the mutants develop the ability to synthesize the vitamin. This is most likely due to

conjugation

Natural selection is best defined as

differential reproductive success among members of a population.

A chemoautotrophic organism would obtain

energy from inorganic molecules and carbon from carbon dioxide.

Changes in the genetic structure of a population over time is the definition of

evolution

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 bacteria is a ________________.

facultative anaerobe

You are studying a species of prokaryote that you have isolated from the digestive tract of a sheep housed at the Penn State barns. It is causing illness among the sheep and you want to determine what type of organism it is. You analyze its cell wall and determine that peptidoglycans are present. You then stain it with gram stain, and discover that it does not take the stain well, turning only a light pink. Based upon this, you determine that it is most likely a:

gram negative bacteria.

Listeria monocytogenes is a bacterium commonly found in soil, stream water, sewage, plants, and food. Listeria is known to be the bacterium responsible for listeriosis, a rare but lethal food-borne infection that has a fatality rate of 25%. Listeria has a cell wall with a thick layer of peptidoglycan and no outer membrane. Based upon these characteristics, this bacterium is

gram positive

The bacterium Streptococcus pneumoniae is the organism responsible for bacterial pneumonia. It has a cell-wall that is predominately made of peptidoglycan and no outer membrane. Based upon these characteristics, this bacterium is __________________. It has the ability to take up DNA from its environment; this ability is known as __________________. Correct!

gram positive / transformation

Gram-positive bacteria

have more peptidoglycan than gram-negative bacteria.

The genetic variation in prokaryotes can arise through:

horizontal gene transfer, conjugation, transformation

Lipids are predominantly hydrophobic because of their ______________.

hydrocarbon chains

Many of the properties of water, including cohesion, the lower density of ice when compared to liquid water, and its high heat of vaporization are a result of the

hydrogen bonds that form between water molecules.

You are studying the chemical reactions that take place when nucleic acids are produced. As you add an enzyme, DNA polymerase, that catalyzes the joining of nucleotides to form DNA, you measure the concentration of water molecules in the solution. You predict that as this reaction continues, the number of water molecules in the reaction solution will

increase

Natural selection _______________________.

is the process by which a population becomes better adapted to its' environment over time

Members of domain Bacteria

lack membrane-bound organelles and do not have introns

A saprobe is an organism that ________.

lives off decaying matter

Lard is solid at room temperature, whereas fish oil is a liquid. You extract the fatty acid molecules from both of these fats and compare their chemical composition. Based just on your knowledge of their state at room temperature, you hypothesize that the fatty acids from the lard will contain __________ hydrogen atoms when compared to the fatty acids found in fish oil.

more

The Hawaiian Bobtail squid (Euprymna scolopes) is a small nocturnal marine invertebrate. It is best known for its light organ, which contains only one species of bacteria (Vibrio fischeri). The squid acquires these bacteria from the water shortly after hatching. These bacteria produce bioluminescence, which obscures the shape of the squid to help it avoid predators. The squid provides nutrients for the bacteria. The relationship between the squid and the bacterium is:

mutualism

The relationship between a legume and bacteria in its root nodules is best described as ________________.

mutualism

___________ is when organisms of different species both benefit by living intimately for extended periods of time.

mutualism

The guts of termites house a complex community of protists and bacteria that help the termite to use cellulose as a food source. Protists of the genus Pseudotrychonympha found in the termite gut house endosymbiotic bacteria that aid the protists in producing the enzymes necessary for cellulose digestion. The energy and nutrients that are released during cellulose digestion is provided to the termite, the protist, and the bacterium. In this system, the relationship between the termite and the bacterium is ______________ and the relationship between the protist and the bacterium is _____________________.

mutualism / mutualism

Bifidobacterium is a genus of bacteria found in the human gut. Bifidobacteria aid in digestion, are associated with a lower incidence of allergies and also have been shown to prevent some forms of tumor growth. In rare cases, however, the bacteria can cause a severe infection. The primary relationship between Bifidobacteria and humans is best described as

mutualistic

Which of the following features can be used to distinguish bacteria from archaea?

one has genes that appear more eukaryotic in character

An obligate anaerobe is an organism that

only grows in the absence of oxygen.

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?

oxygen

Amino acids are joined by _________

peptide bonds

Prokaryotes' cell walls differ from eukaryotes' cell walls in that they have _____________________.

peptidoglycan

Rhodobacter sphaeroides is a purple bacteria. It usually gets its energy from sunlight and its carbon from organic molecules. If there is no sunlight, it can obtain energy from organic molecules. Therefore, this bacterium is

photoheterotroph, chemoheterotroph

A chemoheterotroph will display _________________.

positive chemotaxis

Vibrio anguillarium is an economically important pathogen of fish grown in fish farms. The bacteria are attracted to the amino acids and carbohydrates that are found in the mucus on the skin and in the intestines of the fish. Vibrio anguillarium finds a host fish using:

positive chemotaxis.

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 ____________.

positive phototaxis

The genes found in a DNA molecule code for

proteins.

Dendrochronology is especially useful when estimating ________

relatively recent climate patterns

A coccus bacterium, such as Streptococcus pneunoniae, would be ________________.

round

All of the following are functions of proteins

skin coloration, digestion and oxygen transportation

Radiocarbon dating is appropriate to use when estimating the dates of fossils deposited at the time of _________.

the first European occupation of the New World (less than 10,000 years ago)

In a hypothetical situation, the genes for sex pilus construction and for antibiotic 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

the rapid spread of antibiotic resistance to other bacteria in that habitat.

Ice floats in liquid water because:

the water molecules in ice are held further apart than the molecules in liquid water.

Life can ONLY be defined as ______.

there is no single definition for life

Prokaryotes that are gram-negative _________________.

typically have little peptoglycan

RNA's nitrogenous bases include ____________.

uracil and guanine

The diversity of carbon compounds is largely due to carbon's ________________.

valence of four

The fossil record is more complete for vertebrate animals than it is for plants. This is most likely because

vertebrate animals have hard body parts that fossilize more readily than soft plant bodies.

A phage is a ________________.

virus that infects a bacterium