Deck 24: Microbes and the Environment

Question 1

The primary role of producers is the recycling of nutrients in an ecosystem.

Answer 1

False

Question 2

Scientists have learned the full extent of viral abundance on earth because _______.

A) viruses are known to grow on all life forms: animal, plant, fungi, and bacteria
B) metagenomic sequencing has identi?ed viruses in a broad variety of environments
C) the ?nal step of the viral life cycle, release of mature viruses and cell lysis, releases millions of viruses
D) a wide variety of microbes is available to act as hosts for these viruses

Answer 2

metagenomic sequencing has identi?ed viruses in a broad variety of environments

Question 3

Why are waterlogged soils often infertile?

A) Nitrifying bacteria require oxygen, and the excess water takes the place of oxygen- containing air.
B) There is less carbon in waterlogged soil than dry soil.
C) The lack of physical space in this type of soil blocks bacterial growth.
D) Water molecules are used instead of oxygen for cellular respiration.

Answer 3

Nitrifying bacteria require oxygen, and the excess water takes the place of oxygen- containing air.

Question 4

The terrestrial realm of the biosphere is distributed into particular climatic regions called ______.

A) populations
B) habitats
C) communities
D) biomes
E) niches

Question 5

The study of interactions between microbes and their environment and how those interactions affect the earth is called ______.

A) industrial microbiology
B) biotechnology
C) microbial ecology
D) bioengineering
E) applied microbiology

Question 6

The conversion of nitrate (NO3-) to nitrogen gas (N2) is called ______.

A) ammoni?cation
B) nitri?cation
C) denitri?cation
D) nitrogen ?xation
E) photosynthesis

Question 7

The conversion of gaseous nitrogen (N2) to ammonia (NH?+) occurs during ______.

A) nitrogen ?xation
B) nitri?cation
C) denitri?cation
D) photosynthesis
E) ammoni?cation

Question 8

The oxidation of ammonia (NH?+) to nitrate (NO3-) and nitrite (NO?-) is called ______.

A) denitri?cation
B) photosynthesis
C) ammoni?cation
D) nitri?cation
E) nitrogen ?xation

Question 9

The major group of organisms that ?x nitrogen into ammonia and then oxidize it to nitrate are ______.

A) protozoa
B) algae
C) fungi
D) bacteria

Question 10

The physical location in the environment to which an organism has adapted is its ______.

A) habitat
B) niche
C) population
D) community
E) biome

Question 11

The study of the practical uses of microbes in various industries and technologies is ______.

A) industrial microbiology
B) bioengineering
C) microbial ecology
D) biotechnology
E) applied microbiology

Question 12

The thin envelope of life that surrounds the earth's surface is called the ______.

A) atmosphere
B) ecosystem
C) lithosphere
D) hydrosphere
E) biosphere

Question 13

A collection of organisms, together with the physical and chemical factors in their environment, are called a/an ______.

A) ecosystem
B) lithosphere
C) biosphere
D) atmosphere
E) hydrosphere

Question 14

Which environment represents the largest pool of microbial genes?

A) Oceans
B) Freshwater lakes
C) Rainforest
D) Humans and animals
E) Soil

Question 15

The full extent of the diversity and abundance of life on earth has only been understood in the past few years as a result of _______.

A) advances in deep oceanography and deep earth mining engineering
B) techniques to identify organisms that do not rely on culturing
C) microscopy techniques to identify the vast quantity of viruses present in all environments
D) environmental movements to preserve parks, coral reefs, and glaciers

Question 16

You have been using massive amounts of weed killer and insecticide to kill weeds in your yard, as well as the grubs and aphids that are munching on your roses and your grass. What effect might this have from a microbiological standpoint?

A) Loss of microbial diversity in the soil
B) Reduction in microbial numbers in the soil
C) Damage to the nitrogen ?xing bacteria
D) Damage to the mycorrhizae
E) All of the choices are correct.

Question 17

Phytoplankton is composed of protozoa and small invertebrates.

Question 18

Living or dead organisms that occupy an organism's habitat are called biotic factors.

Question 19

Both energy and nutrients cycle through an ecosystem.

Question 20

A group of organisms of the same genus within a community is called a ______.

A) biome
B) population
C) niche
D) habitat
E) community

Question 21

Which of the following statements regarding the phosphorus cycle is incorrect?

A) Thiobacillus produces sulfuric acid that dissolves phosphate rock.
B) Phosphorus mineralization occurs by microbial action.
C) Phosphorus must be phosphatized to enter biological systems.
D) The phosphorus pool is in sedimentary rock.
E) Phosphorus is released naturally by mining.

Question 22

Carbon dioxide (CO?) is _______.

A) removed from the atmosphere during photosynthesis
B) a source of carbon for autotrophs
C) returned to the atmosphere during respiration and fermentation
D) used by marine organisms to make limestone for their hard shells
E) All of the choices are correct.

Question 23

Which crop plant would likely have a mutualistic relationship with Rhizobium bacteria?

A) Peas
B) Cotton
C) Corn
D) Wheat
E) Potatoes

Question 24

When methanogens convert carbon dioxide to methane, it is a/an ______ reaction.

A) reduction
B) aerobic
C) oxidation
D) ammoni?cation

Question 25

Methane is a signi?cant part of the carbon cycle in ______ environments dominated by methanogens.

A) oligotrophic
B) thermophilic
C) anaerobic
D) autotrophic

Question 26

A Paramecium is an example of a ______.

A) primary producer
B) quaternary consumer
C) secondary consumer
D) primary consumer
E) tertiary consumer

Question 27

The advantage of nitrogen ?xation to the host plant is _______.

A) the production of nucleotides required for nucleic acid synthesis
B) the ability to synthesize amino acids and proteins from the ammonia produced
C) the ability to use nitrogen gas instead of oxygen gas in cellular respiration, particularly when the soil is compacted
D) the production of antibiotics that protect the plant against pathogenic soil bacteria

Question 28

Organisms that inhabit soil or water and breakdown and absorb the organic matter of dead organisms are called ______.

A) secondary consumers
B) autotrophs
C) primary consumers
D) decomposers

Question 29

Which organism is a nitrogen-?xing symbiont of legumes?

A) Rhizobium
B) Pseudomonas
C) Nitrobacter
D) Clostridium

Question 30

Toxic substances accumulate through natural trophic flow of an ecosystem.

Question 31

Which trophic level forms the base of a food chain?

A) Secondary consumers
B) Tertiary consumers
C) Primary producers
D) Primary consumers
E) Quaternary consumers

Question 32

Which of the following is a source of methane?

A) Gastrointestinal tract of cattle and sheep
B) Photosynthesis from halophiles in the Dead Sea
C) Decomposition of organic detritus on the forest ?oor
D) Degradation of cellulose and lignin by fungi
E) All of these processes produce methane.

Question 33

Organisms whose sole source of carbon for growth is CO? are called ______.

A) decomposers
B) saprophytes
C) lithotrophs
D) autotrophs
E) consumers

Question 34

Chemical elements needed in trace amounts for biochemical reactions have a biogeochemical cycle, including boron, chromium, manganese, and cobalt.

Question 35

Which of the following organisms anaerobically reduces sulfates to hydrogen sul?de or metal sul?de?

A) Nitrosococcus
B) Desulfovibrio
C) Thiobacillus thiooxidans
D) Rhizobium
E) Thiobacillus ferrooxidans

Question 36

The combustion of fossil fuels, such as coal, oil, and gas, have contributed to the steady increase in atmospheric CO? gas over the last 25 years.

Question 37

The energy of the sun is converted into chemical energy during ______.

A) photosynthesis
B) ammoni?cation
C) nitri?cation
D) denitri?cation
E) nitrogen ?xation

Question 38

Which of the following statements regarding biogeochemical cycles is incorrect?

A) Elements cycle through biotic and abiotic environments.
B) Recycling keeps nutrients in balance.
C) All elements originate from a nonliving, long-term reservoir.
D) All organisms directly participate in recycling.
E) Cycles are simple systems between living and nonliving components.

Question 39

There are very few viruses in aquatic environments.

Question 40

Heterotrophs include _______.

A) producers only
B) consumers only
C) consumers and decomposers
D) producers and consumers
E) producers, consumers, and decomposers

Question 41

Which microorganism is considered phytoplankton?

A) Nitrogen ?xing bacteria
B) Sulfate reducers
C) Cyanobacteria
D) Mycorrhizae

Question 42

Vast numbers of microorganisms are being genetically characterized without culturing them in the laboratory today through ______.

A) column chromatography
B) metagenomic sequencing
C) mass spectrometry and proteomics
D) polymerase chain reaction

Question 43

Select the statement that explains the usefulness of metagenomic analysis in research today.

A) It evaluates microbial diversity in a habitat.
B) It allows the identi?cation of unculturable microorganisms.
C) It detects the abundance of microorganisms in an environment.
D) All of these are correct statements.

Question 44

The slowly decaying organic litter from plant and animal tissues that is found in the soil is called ______.

A) a bio?lm
B) aggregate
C) detritus
D) the lithosphere

Question 45

Which of the following is true of water-saturated soils?

A) They contain anaerobes.
B) They provide gases for soil microbes.
C) They have a high oxygen content.
D) They have a low carbon dioxide content.

Question 46

The mutualistic partnership between plant roots and microbes is ______.

A) rhizopods
B) mycorrhizae
C) basidia
D) hyphae
E) lichens

Question 47

You have been diagnosed with neurotoxic poisoning after having ingested an algal toxin, called brevetoxin, produced by Karenia brevis. In which food did you likely consume this?

A) Oysters
B) Tomatoes
C) Canned tuna
D) Freshwater trout

Question 48

The bacterium Thiobacillus secretes sulfuric acid into the environment.

Question 49

The majority of Earth's water is found in ______.

A) oceans
B) soil moisture
C) ground water
D) icecaps and glaciers
E) freshwater lakes

Question 50

Plastic marine debris was collected from multiple sites in the ocean and examined with electron microscopy and next-generation sequencing. These techniques revealed microbial communities growing on the plastics. Which of the following statements is correct regarding these communities?

A) At least one member of the community must synthesize an enzyme to degrade the hydrocarbon comprising the plastic.
B) There are no bacteriophage that use these microbes as hosts, as viruses are rare in marine ecosystems.
C) The community within the plastic must be very similar to the community in the surrounding ocean waters.
D) These communities are very likely to be pure cultures, as plastics have been synthesized precisely because they are resistant to microbial degradation.

Question 51

Metagenomic analysis involves DNA sequencing of various samples taken from a particular habitat.

Question 52

How are the sulfur cycle and the phosphate cycle interconnected?

A) Phosphate is released from rock and soil by sulfuric acid.
B) Sulfate and phosphate react together to produce amino acids for protein production.
C) Sul?te is the nutrient used by phosphate reducers.
D) Phosphate is the nutrient source used by sulfur oxidizers.

Question 53

Which of the following statements concerning metagenomic sequencing is incorrect?

A) The samples are subject to polymerase chain reaction for ampli?cation.
B) The sequences of the ampli?ed fragments are determined by next-generation methods.
C) Software aligns sequences and assemble large portions of genomes.
D) Proteins are extracted from an environment, fragmented, and adaptors are added.

Question 54

You have drained a pond on your property to make it deeper. In the process of using a machine to dig, you ?nd that the mud is black and smells terrible. Your prediction is that ______ bacteria predominate in this area of the mud.

A) sulfur-reducing
B) sulfur-oxidizing
C) denitrifying
D) nitrogen-?xing
E) nitrifying

Question 55

The zone of soil around roots of plants is called the ______.

A) ionosphere
B) rhizosphere
C) biosphere
D) hydrosphere
E) lithosphere

Question 56

Most of the organic sulfur is located in _______.

A) nucleotides and nucleic acids
B) monosaccharides and carbohydrates
C) fatty acids and lipids
D) amino acids and proteins

Question 57

The total amount of water in the hydrologic cycle has been decreasing over the last million years.

Question 58

Which of the following processes is not a part of metagenomic analysis of an environment?

A) DNA sequence assembly
B) Polymerase chain reaction
C) High-throughput sequencing
D) Extraction of DNA from original sample
E) Reverse transcription

Question 59

You are preparing a garden and want to provide the best environment for your plants. Which of the following would you add to the potting soil?

A) Sulfur oxidizers
B) Mycorrhizae inoculant
C) Bacteriophage
D) Coliform bacteria

Question 60

Mycorrhizae are the mutualistic relationship between fungi and the roots of certain plants.

Question 61

The thermocline is broken down by temperature changes that allow upwelling to occur.

Question 62

The three components that interact for one health are _______.

A) the environment, humans, and animals
B) prokaryotes, eukaryotes, and viruses
C) bacteria, archaea, and eukaryotes
D) producers, consumers, and decomposers

Question 63

Considering the increase in tick-borne diseases in the context of "One Health," which of the following statements is correct?

A) Lyme disease has spread from deer to humans upon increasing development of the forested environments usually inhabited by deer.
B) Ticks carrying multiple pathogens reproduce at a slower rate, rendering them less likely to infect humans.
C) Borrelia, Babesia, and Ehrlichia can rapidly adapt to changing insect vectors, thereby increasing their populations as they move from ticks to mosquitoes.
D) Ticks carrying Borrelia are likely to encounter hosts already infected with Babesia or Ehrlichia, resulting in ticks that co-infect with multiple pathogens.

Question 64

Eutrophication _______.

A) is characterized by heavy surface algal blooms
B) restricts the O? supply to water below the surface
C) occurs when there are excess nutrients in aquatic ecosystems
D) causes massive die-off of ?sh and invertebrates
E) All of the choices are correct.

Question 65

The warmest area of a lake during the summer is the ______.

A) benthic zone
B) thermocline
C) hypolimnion
D) epilimnion
E) limnion

Question 66

Looking at the use of antibiotics as growth promoters in livestock through the lens of "One Health," which of the following statements best describes the interrelationship of these components of the biosphere?

A) Choosing a vegetarian lifestyle goes a long way to avoid risks associated with antibiotic- treated livestock.
B) Spontaneous antibiotic resistance that arises in animals can be rapidly spread to humans who work on factory farms.
C) The broad range of antibiotics available will provide widespread protection from pathogenic microbes.
D) Livestock can be more susceptible to infectious diseases because of the energy required for such rapid growth.

Question 67

Nutrient de?cient aquatic ecosystems are called ______.

A) autotrophic
B) oligotrophic
C) eutrophic
D) hypotrophic
E) epitrophic

Question 68

The breakdown of man-made compounds by decomposers is called ______.

A) saprobism
B) decomposition
C) mineralization
D) bioremediation
E) parasitism

Question 69

Considering the human body as an ecosystem, which of the following statements is incorrect?

A) Energy for the human microbiome derives exclusively from the food we eat.
B) The microbiota in the human gut is comprised of heterotrophs.
C) The human ecosystem lacks an autotrophic niche.
D) Microbes act as producers, consumers, and decomposers within the human ecosystem.

Question 70

Which of the following types of microbes is most likely to be found in the sediment of Lake Michigan?

A) Anaerobes; oxygen is least abundant in the sediment layer
B) Autotrophs; their carbon source is dissolved carbon dioxide
C) Mesophiles; temperatures in the hypolimnion support growth in the 4-9°C range
D) Cyanobacteria; seasonal upwelling of nutrients can cause dramatic increases in their numbers

Question 71

You are "living off the grid" meaning that you are not using any public utilities: no water supply, sewer connection, natural gas, or electricity. You do have a septic tank, whose pipe carries sewage underground where it is released over a wide area, the leaching ?eld. There is also a small pond out there that you have stocked with ?sh. However, you notice that the ?sh are ?oating dead in the water, and the pond has a green scum on it. What happened?

A) Chemical toxins from your septic tank cleaner have killed the ?sh.
B) There are not enough nutrients in the water, so the ?sh died.
C) The ?sh died due to a lack of calcium, which then caused the algae to overgrow.
D) There is oxygen depletion in the pond due to the leakage of phosphates and other compounds from your septic tank.

Question 72

Consider a deep sea hydrothermal vent. Which of the following statements is incorrect?

A) Its biome is the deep marine biopshere.
B) The vent hosts communities of chemolithotrophic bacteria.
C) The vent is a habitat.
D) The associated chemolithotrophs are primary producers.

Question 73

Which of the following statements considering the human body as an ecosystem is incorrect?

A) An infection can be considered a habitat's response to an alteration in environmental conditions.
B) Lactobacillus acidophilus and Lactobacillus jensenii are populations within the vaginal community.
C) The microbes present in dental plaque constitute a community.
D) The skin, the gut, and the nasopharynx are all habitats.

Question 74

Which of the following statements regarding red tides is incorrect?

A) Red tides result from an overgrowth of dino?agellates.
B) Toxins produced by dino?agellates are skin irritants.
C) Red tides are also known as harmful algal blooms (HABs).
D) Dino?agellates produce a toxin that causes paralytic shell?sh poisoning.

Question 75

Which of the following statements regarding the infection of root hairs by Rhizobium species is incorrect?

A) Attachment of Rhizobium cells to plant root hair cells induce curling of the root hair.
B) This is a mutualistic relationship between plant and bacteria.
C) Nodules begin to form in the roots as both plant and bacterial partners differentiate.
D) The presence of Rhizobium triggers the formation of syncytial cells.

Question 76

Using microbes to break down or remove toxic wastes in water and soil is called ______.

A) recycling
B) bioremediation
C) synergism
D) decomposition
E) mineralization