Deck 15: The Evolution of Microbial Life

Question 1

Which group of prokaryotes aids digestion in cattle, deer, and other animals that obtain nutrition from cellulose?

A)halophiles
B)dinoflagellates
C)methanogens
D)cocci

Answer 1

C

Question 2

Which gas began to increase in the atmosphere as a result of photosynthesis by autotrophic prokaryotes approximately 2.7 billion years ago?

A)methane
B)carbon dioxide
C)oxygen
D)hydrogen

Answer 2

C

Question 3

Which groups of organisms colonized land during the Paleozoic era approximately 500 million years ago?

A)plants, protists, and insects
B)plants, fungi, and insects
C)bacteria, plants, and fungi
D)protists, bacteria, and fungi

Answer 3

B

Question 4

Scientists hypothesize that disrupting our ________ communities may increase our susceptibility to infectious diseases, predispose us to certain cancers, and contribute to conditions such as asthma and other allergies, irritable bowel syndrome, Crohn's disease, and autism.

A)microbial
B)plant
C)protist
D)pathogen

Question 5

Ribosomes can perform some of the functions of both ________ and ________.

A)cocci; bacilli
B)DNA; protein
C)lysosomes; ATP molecules
D)algae; amoebas

Question 6

Which organisms would likely be the most difficult to kill if you were you to can your own food?

A)streptococci
B)endospores
C)biofilms
D)staphylococci

Question 7

Eukaryotes arose about ________ years after the first prokaryotes.

A)3)0 million
B)1)7 billion
C)3)5 billion
D)4)0 billion

Question 8

The prokaryotic group that tends to inhabit extreme environments belongs to ________.

A)Protista
B)Archaea
C)Euglena
D)Bacteria

Question 9

Bacilli are ________ prokaryotes.

A)spherical
B)comma-shaped
C)rod-shaped
D)spiral

Question 10

Why is RNA thought to have been the first genetic material?

A)RNA is structurally simpler than DNA.
B)RNA has been found on meteorites.
C)RNA is capable of self-replication.

Question 11

From what can pre-cells spontaneously form?

A)ribozymes
B)RNA
C)fatty acids
D)DNA

Question 12

What was the third stage of the process that led to the abiotic origin of life?

A)synthesis of small organic molecules, such as amino acids and nucleotide monomers
B)origin of self-replicating molecules
C)synthesis of polymers, such as proteins and nucleic acids
D)formation of pre-cells

Question 13

The absence of ________ in the primitive atmosphere was essential to the origin of life on Earth.

A)N₂
B)CO₂
C)CH₄
D)O₂

Question 14

Based on fossil evidence, eukaryotes evolved about ________ years ago.

A)500,000
B)1 billion
C)1)8 billion
D)3)5 billion

Question 15

Land was first colonized about ________ years ago.

A)100 million
B)500 million
C)1)7 billion
D)2)5 billion

Question 16

Variation among pre-cells was due to ________.

A)genetic drift
B)natural selection
C)the bottleneck effect
D)mutation

Question 17

Which statement is FALSE?

A)The great diversification of animals occurred during the Cambrian explosion.
B)For most of biological history, life was confined to aquatic habitats.
C)The evolution of multicellularity took place after the origin of the eukaryotes.
D)The first organisms to colonize land were animals.

Question 18

Large, diverse, multicellular organisms first appeared in the fossil record approximately ________ million years ago during the ________.

A)290; Paleozoic era
B)600; Paleozoic era
C)363; Mesozoic era
D)50; Mesozoic era

Question 19

Spherical bacteria that occur in clusters are ________.

A)streptococci
B)bacilli
C)spirochetes
D)staphylococci

Question 20

Which prokaryotic group is most closely related to eukaryotes?

A)Bacteria
B)Protista
C)Archaea

Question 21

What are the two classes of poisons produced by pathogenic bacteria?

A)exotoxins and endotoxins
B)chemoautotrophs and chemoheterotrophs
C)protozoans and fungi
D)bacilli and cocci

Question 22

Under ideal conditions, prokaryotes are capable of reproducing at a(n)________ rate.

A)negative
B)exponential
C)variable

Question 23

Trichomonas vaginalis is a protozoan that feeds on white blood cells and bacteria living on the cells lining the female human vagina, thereby creating a common sexually transmitted disease often known as "trich." The feeding mechanism of this protozoan makes it a ________.

A)parasite
B)autotroph
C)producer
D)mixotroph

Question 24

Recent scientific studies of the impact of microbiota on the amount of fat versus lean body mass (i.e., body composition)are described in your text. How do those studies illustrate the importance of microbiota communities in our bodies?

A)If transferred to lean humans, intestinal microbiota of obese humans will cause obesity.
B)If transferred to obese humans, intestinal microbiota in lean humans will cause exaggerated obesity.
C)The studies suggest that mice are an unreliable model organism to use for studies of human intestinal microbiota and obesity.
D)The studies suggest that intestinal microbiota may be involved in regulating our digestive processes.

Question 25

Eukaryotes that are not fungi, animals, or plants are classified in a "catch-all" category called ________.

A)archaea
B)bacteria
C)seaweeds
D)protists

Question 26

A protist with a shell made of silica is most likely a(n)________.

A)apicomplexan
B)foram
C)dinoflagellate
D)diatom

Question 27

Food poisoning from Salmonella occurs because of ________.

A)an exotoxin secreted by Salmonella bacteria
B)an endotoxin produced by Salmonella bacteria
C)transmission between people living in close contact
D)extremophile conditions

Question 28

________ is an example of bioremediation.

A)Cyanobacteria converting atmospheric nitrogen to a form that plants can use
B)The use of an autoclave to kill endospores
C)The use of prokaryotes to treat sewage
D)A dinoflagellate bloom causing massive fish kills

Question 29

Which organism is a colonial form of green algae?

A)Volvox
B)Giardia
C)Paramecium
D)Plasmodium

Question 30

________ include cells that can function either independently or as a single unit.

A)dinoflagellates
B)forams
C)seaweeds
D)cellular slime molds

Question 31

What accounts for the similarity between seaweeds and plants?

A)symbiosis
B)convergent evolution
C)evolutionary fitness

Question 32

Prokaryotes reproduce by means of ________.

A)mitosis
B)binary fission
C)budding
D)meiosis

Question 33

Flagellates, amoebas, apicomplexans, and ciliates are all what type of protist?

A)slime molds
B)protozoans
C)dinoflagellates
D)seaweeds

Question 34

You discover a unicellular organism that moves by what appear to be pseudopodia. You conclude that this organism could be ________.

A)a type of amoeba, foram, or slime mold
B)a type of bacterium
C)a type of alga
D)a type of ciliate or a type of apicomplexan

Question 35

________ are responsible for toxic red tides.

A)Plasmodial slime molds
B)Dinoflagellates
C)Red algae
D)Diatoms

Question 36

Which protozoan group has primarily been identified through fossils?

A)forams
B)ciliates
C)flagellates
D)amoebas

Question 37

Which group of organisms is most closely related to plants?

A)brown algae
B)red algae
C)slime molds
D)green algae

Question 38

All organisms that photosynthesize fit into which nutritional category?

A)mixotroph
B)heterotrophs
C)autotrophs
D)parasites

Question 39

In Yellowstone National Park, hot springs can reach temperatures of 205°F (96°C). Despite these high temperatures, Aquifex bacteria flourish. How might one best classify Aquifex bacteria?

A)slime molds
B)extremophiles
C)amoebas
D)algae

Question 40

In the soil, some ________ help to decompose dead organisms and other waste materials, returning vital chemical elements such as nitrogen to the environment.

A)pre-cells
B)protozoans
C)prokaryotes

Question 41

Plasmodium illustrate feeding characteristics of a(n)________.

A)slime mold
B)ciliate
C)apicomplexan
D)algae

Question 42

Which reasoning is a plausible explanation for why it may be difficult to treat infections that arise from tooth decay?

A)Biofilm bacteria that cause tooth decay begin to produce endospores as a means to deter effects of antibiotics.
B)Binary fission in biofilm bacteria that cause tooth decay begins to decrease as the biofilm community becomes more complex, thereby producing fewer bacterial cells for antibiotics to penetrate.
C)As the biofilm that causes tooth decay becomes larger, its structure makes it difficult for antibiotics to break through bacterial cell walls.
D)Bacteria of the biofilm that cause tooth decay form a symbiotic relationship with the antibiotics and therefore diminish antibiotic effectiveness.

Question 43

Read the following scenario to answer the following question(s).
Endotoxins are commonly found in the air, both inside and outside our homes. These "air endotoxins" can come from sources that include house dust mites, agricultural and industrial dust, and dust from indoor pets. Air endotoxins are typically found in low amounts, but production of them can increase dramatically under specific environmental conditions such as dampness, mold, and sewage. Many scientific studies have been conducted investigating possible links between indoor endotoxin levels and asthma, chronic bronchitis, and other upper respiratory diseases. Interestingly, some studies have found positive correlations between indoor endotoxin exposure and severity of some of these diseases while other studies have suggested that some air endotoxin exposure can actually decrease the risk of developing asthma in children. Additionally, data suggest that industrial workers who are exposed to endotoxins in the air can develop irreversible lung damage.
In 2005, Hurricane Katrina devastated the eastern coastline of the United States. The state of Louisiana, and in particular the city of New Orleans, experienced tragic loss of human life and homes due to the failure of the levee system. Intense flooding destroyed homes and created severe exposure to wet, moldy surfaces. At that time there were no regulations in existence on the amount of exposure that individuals should have to air endotoxins. Scientists from the Natural Resources Defense Council who wanted to determine if endotoxin levels had risen in New Orleans conducted tests across 12 outdoor areas, 9 of which had been significantly flooded while the other 3 were less affected. Two indoor areas were also sampled for endotoxin levels. No significant differences were found in endotoxin levels between the flooded and non-flooded areas or between the indoor and outdoor areas. However, a limited number of samples were collected, and they were taken after a recent dry spell. Endotoxin levels at all sites were found to be higher than national average levels but were lower than levels typically associated with long-term changes in lung function.
What addition to methodology would be most beneficial to the study?

A)pre-flood data to compare to post-flood data in order to better compare endotoxin levels
B)a greater number of scientists conducting tests so that different testing methods can be used at each site
C)tests conducted on soil endotoxins to compare to air endotoxin levels
D)tests conducted on bacterial exotoxins in New York City

Question 44

A vector is an organism that transfers a pathogen to a host. In the case of malaria, the vector(s)is (are)________.

A)humans only
B)humans and Anopheles mosquitoes
C)Anopheles mosquitoes only
D)humans, Plasmodium, and Anopheles mosquitoes

Question 45

Read the following scenario to answer the following question(s).
Malaria is a disease caused by parasitic protists in the genus Plasmodium. The parasite is transmitted to humans by female Anopheles mosquitoes. The Plasmodium parasite feeds on human red blood cells, eventually destroying them. Humans infected with malaria can exhibit many symptoms. Depending on the severity of the infection, these can range from fever, chills, sweating, and headaches to anemia and kidney failure. Ultimately, malaria can result in death. However, if time and money permit, once a person is infected, they can be treated with different antimalarial drugs. Two commonly used drugs are artemisinin and quinine. In addition, one way to prevent the spread of malaria is to apply pesticides to treat areas with Anopheles mosquitoes. The National Malaria Eradication Program began work in 1947 with the goal of eliminating malaria from the southern United States. In 1947, 15,000 cases of malaria were reported nationwide. By 1950, only 2,000 cases were reported, and by 1951, malaria was considered eradicated from the United States. Today, the disease is most common in Africa and South America, two continents that are highly impoverished. About one million people die from malaria every year, many of them children. In Africa, it is estimated that one in every five childhood deaths is due to malaria.
If an area infested with female Anopheles mosquitoes is treated with pesticides, and these mosquitos live, continue to breed, and continue to spread malaria, what can we conclude?

A)Alleles that are resistant to the pesticides are being selected for, so female Anopheles mosquitoes may continue to infect humans.
B)Malaria is not actually caused by the Plasmodium parasite.
C)Male Anopheles mosquitoes are also carriers of the Plasmodium parasite.
D)The people are becoming resistant to the pesticide.

Question 46

Read the following scenario to answer the following question(s).
Endotoxins are commonly found in the air, both inside and outside our homes. These "air endotoxins" can come from sources that include house dust mites, agricultural and industrial dust, and dust from indoor pets. Air endotoxins are typically found in low amounts, but production of them can increase dramatically under specific environmental conditions such as dampness, mold, and sewage. Many scientific studies have been conducted investigating possible links between indoor endotoxin levels and asthma, chronic bronchitis, and other upper respiratory diseases. Interestingly, some studies have found positive correlations between indoor endotoxin exposure and severity of some of these diseases while other studies have suggested that some air endotoxin exposure can actually decrease the risk of developing asthma in children. Additionally, data suggest that industrial workers who are exposed to endotoxins in the air can develop irreversible lung damage.
In 2005, Hurricane Katrina devastated the eastern coastline of the United States. The state of Louisiana, and in particular the city of New Orleans, experienced tragic loss of human life and homes due to the failure of the levee system. Intense flooding destroyed homes and created severe exposure to wet, moldy surfaces. At that time there were no regulations in existence on the amount of exposure that individuals should have to air endotoxins. Scientists from the Natural Resources Defense Council who wanted to determine if endotoxin levels had risen in New Orleans conducted tests across 12 outdoor areas, 9 of which had been significantly flooded while the other 3 were less affected. Two indoor areas were also sampled for endotoxin levels. No significant differences were found in endotoxin levels between the flooded and non-flooded areas or between the indoor and outdoor areas. However, a limited number of samples were collected, and they were taken after a recent dry spell. Endotoxin levels at all sites were found to be higher than national average levels but were lower than levels typically associated with long-term changes in lung function.
What is a logical conclusion to draw from this study?

A)Workers that come to these areas to help rebuild do not need to be concerned with indoor air endotoxin levels.
B)Workers that come to these areas where there was flooding damage should be advised to wear protective respiratory gear.
C)Workers that come to these areas to help rebuild do not need to be concerned with outdoor air endotoxin levels.
D)Workers that come to these areas to help rebuild buildings can assume that they will develop an irreversible lung infection.

Question 47

In the associated image, the aquatic organism moves using flagella. It is parasitic and can colonize and reproduce in the human intestine. What type of organism could this be?

A)a protozoan
B)a slime mold
C)phytoplankton
D)seaweed

Question 48

What kind of protist is shown in the figure?

A)ciliate
B)plasmodial slime mold
C)flagellate
D)foram

Question 49

Some aquatic invertebrates such as insects and snails feed on biofilms. Scientists that study metal-contaminated streams have documented that some biofilms in stream environments absorb zinc from stream water during daylight hours and release the zinc into the stream during the night. What might the scientists hypothesize about zinc concentration in the stream?

A)The highest zinc concentrations in stream water might occur only during the day.
B)The highest zinc concentrations in stream water might occur only at night.
C)Zinc concentrations in stream water are likely to be similar during the day and at night.

Question 50

The plasmodium of a plasmodial slime mold can grow in order to enlarge the organism's surface area and therefore potentially obtain more nutrients. This is an example of ________.

A)the relationship between structure and function
B)convergent evolution
C)autotrophy
D)parasitism

Question 51

Suppose production of the pesticides used to treat malaria is halted because the Environmental Protection Agency (EPA)has found that they are causing too much environmental damage to warrant continued use. In turn, this drives up the prices of artemisinin and quinine since they are now in higher demand. How might this affect those that live in South America and Africa?

A)They will likely experience a decrease in the number of male Anopheles mosquitoes.
B)They will likely experience an increase in the number of male Anopheles mosquitoes.
C)They will likely experience a decrease in the number of malaria cases
D)They will likely experience an increase in the number of malaria cases.

Question 52

Some aquatic invertebrates such as insects and snails feed on biofilms. Scientists that study metal-contaminated streams have documented that some biofilms in stream environments absorb zinc from stream water during daylight hours and release the zinc into the stream during the night. If the scientists were to test exposure of the invertebrates to zinc, what might they hypothesize?

A)The greatest exposure to aquatic invertebrates that feed on biofilms might only occur during daylight hours.
B)The greatest exposure to aquatic invertebrates that feed on biofilms might only occur during night hours.
C)Aquatic invertebrates that prefer to feed at night will encounter little exposure to zinc.

Question 53

By the end of the ________, all major body plans and major groups of organisms had evolved.

A)Mesozoic era
B)Paleozoic era
C)Cambrian explosion

Question 54

According to this evolutionary tree, the archaea and eukaryotes last shared a common ancestor ________.

A)1)0 billion years ago
B)1)75 billion years ago
C)2)5 billion years ago
D)3)5 billion years ago

Question 55

Read the following scenario to answer the following question(s).
Endotoxins are commonly found in the air, both inside and outside our homes. These "air endotoxins" can come from sources that include house dust mites, agricultural and industrial dust, and dust from indoor pets. Air endotoxins are typically found in low amounts, but production of them can increase dramatically under specific environmental conditions such as dampness, mold, and sewage. Many scientific studies have been conducted investigating possible links between indoor endotoxin levels and asthma, chronic bronchitis, and other upper respiratory diseases. Interestingly, some studies have found positive correlations between indoor endotoxin exposure and severity of some of these diseases while other studies have suggested that some air endotoxin exposure can actually decrease the risk of developing asthma in children. Additionally, data suggest that industrial workers who are exposed to endotoxins in the air can develop irreversible lung damage.
In 2005, Hurricane Katrina devastated the eastern coastline of the United States. The state of Louisiana, and in particular the city of New Orleans, experienced tragic loss of human life and homes due to the failure of the levee system. Intense flooding destroyed homes and created severe exposure to wet, moldy surfaces. At that time there were no regulations in existence on the amount of exposure that individuals should have to air endotoxins. Scientists from the Natural Resources Defense Council who wanted to determine if endotoxin levels had risen in New Orleans conducted tests across 12 outdoor areas, 9 of which had been significantly flooded while the other 3 were less affected. Two indoor areas were also sampled for endotoxin levels. No significant differences were found in endotoxin levels between the flooded and non-flooded areas or between the indoor and outdoor areas. However, a limited number of samples were collected, and they were taken after a recent dry spell. Endotoxin levels at all sites were found to be higher than national average levels but were lower than levels typically associated with long-term changes in lung function.
What is a potential benefit of testing indoor and outdoor sites as well as sites with heavy flooding and light flooding?

A)There is no benefit associated with testing in multiple sites.
B)Testing multiple sites takes less time and requires less equipment.
C)Testing multiple sites allows for fewer scientists to be exposed to the air endotoxins.
D)The data collected would allow scientists to compare endotoxin levels under multiple conditions.

Question 56

Yersinia pestis is a strain of bacteria that caused the "black death" plague that killed more than 50 million people in the 14th century. The bacteria spread quickly and easily through the air and from person to person. Yersinia pestis might be studied by scientists interested in ________.

A)biofilms
B)parasites
C)biological weapons
D)apicomplexans

Question 57

What kind of prokaryotes are shown in the figure?

A)bacilli
B)spirochetes
C)cocci
D)ciliates

Question 58

All of the species in the list below are seaweeds. Which is the EXCEPTION?

A)red algae
B)green algae
C)brown algae
D)diatoms

Question 59

Read the following scenario to answer the following question(s).
Endotoxins are commonly found in the air, both inside and outside our homes. These "air endotoxins" can come from sources that include house dust mites, agricultural and industrial dust, and dust from indoor pets. Air endotoxins are typically found in low amounts, but production of them can increase dramatically under specific environmental conditions such as dampness, mold, and sewage. Many scientific studies have been conducted investigating possible links between indoor endotoxin levels and asthma, chronic bronchitis, and other upper respiratory diseases. Interestingly, some studies have found positive correlations between indoor endotoxin exposure and severity of some of these diseases while other studies have suggested that some air endotoxin exposure can actually decrease the risk of developing asthma in children. Additionally, data suggest that industrial workers who are exposed to endotoxins in the air can develop irreversible lung damage.
In 2005, Hurricane Katrina devastated the eastern coastline of the United States. The state of Louisiana, and in particular the city of New Orleans, experienced tragic loss of human life and homes due to the failure of the levee system. Intense flooding destroyed homes and created severe exposure to wet, moldy surfaces. At that time there were no regulations in existence on the amount of exposure that individuals should have to air endotoxins. Scientists from the Natural Resources Defense Council who wanted to determine if endotoxin levels had risen in New Orleans conducted tests across 12 outdoor areas, 9 of which had been significantly flooded while the other 3 were less affected. Two indoor areas were also sampled for endotoxin levels. No significant differences were found in endotoxin levels between the flooded and non-flooded areas or between the indoor and outdoor areas. However, a limited number of samples were collected, and they were taken after a recent dry spell. Endotoxin levels at all sites were found to be higher than national average levels but were lower than levels typically associated with long-term changes in lung function.
What is an implication of the fact that tests were conducted after a period of dry weather?

A)Dry weather creates harsher sampling conditions for scientists.
B)If more periods of rainfall occur after the testing, bacteria that secrete endotoxins may increase, thereby increasing endotoxin levels.
C)Dry weather increases the amount of carbon available for the endotoxin bacteria to use for organic compound production.
D)Endotoxin bacteria provide greater bioremediation effects in dry weather than in wet weather.