Biology 1720 - Bacteria and Archaea

What kind of organisms lack both membrane-bound organelles and a true nucleus?

a. Multicellular organisms

b. Plants

c. Eukaryotes

d. Prokaryotes

d. Prokaryotes

Approximately how long ago did prokaryotes first appear on Earth?

a. 1.2 billion years ago

b. 3.5 billion years ago

c. 500 million years ago

d. 4.5 million years ago

b. 3.5 billion years ago

Why are prokaryotes described as being ubiquitous?

a. They are confined to extreme conditions.

b. They only exist in water.

c. They are limited to specific environments.

d. They are found everywhere on Earth

d. They are found everywhere on Earth

What is the shape of bacilli (singular: bacillus)?

a. Spherical

b. Spiral

c. Rod-shaped

d. Cuboidal

c. Rod-shaped

How do bacilli typically exist in nature?

a. Always in clusters

b. Only in pairs

c. Usually solitary, but some can form chains

d. Exclusively as colonies

c. Usually solitary, but some can form chains

Which of the following is an example of a bacillus?

a. Staphylococcus aureus

b. Treponema pallidum

c. Pseudomonas aeruginosa

d. Bacillus subtilis

c. Pseudomonas aeruginosa

What is the shape of cocci (singular: coccus)?

a. Rod-shaped

b. Spiral

c. Spherical

d. Oval

c. Spherical

In what arrangements can cocci prokaryotes exist?

a. Solitary, in pairs, or forming clusters

b. Exclusively in pairs

c. Only in chains

d. Only as colonies

a. Solitary, in pairs, or forming clusters

Which of the following is an example of a spherical prokaryote?

a. Treponema pallidum

b. Staphylococcus aureus

c. Pseudomonas aeruginosa

d. Escherichia coli

b. Staphylococcus aureus

What is the shape of spirilla (singular: spirillum)?

a. Rod-shaped

b. Spiral

c. Spherical

d. Elliptical

b. Spiral

Which of the following is an example of a spirillum?

a. Staphylococcus aureus

b. Treponema pallidum

c. Pseudomonas aeruginosa

d. Bacillus subtilis

b. Treponema pallidum

What is the bacterial cell wall primarily made of?

a. Cellulose

b. Peptidoglycan

c. Chitin

d. Lignin

b. Peptidoglycan

What is the composition of peptidoglycan in bacterial cell walls?

a. Lipids and nucleic acids

b. Polysaccharides and proteins

c. DNA and RNA

d. Sugars and fats

b. Polysaccharides and proteins

How do archaea differ from bacteria in terms of their cell walls?

a. Archaea have a thicker peptidoglycan layer

b. Archaea lack peptidoglycan

c. Archaea have cellulose instead of peptidoglycan

d. Archaea have toxic outer membranes

b. Archaea lack peptidoglycan

What method do scientists use to classify bacteria by their cell wall composition?

a. Polymerase Chain Reaction (PCR)

b. Gram stain

c. DNA sequencing

d. Immunostaining

b. Gram stain

What characterizes Gram-positive bacteria?

a. Simpler walls with little peptidoglycan

b. Simpler walls with lots of peptidoglycan

c. Complex walls with toxic outer membranes

d. Lack of peptidoglycan

b. Simpler walls with lots of peptidoglycan

What characterizes Gram-negative bacteria?

a. Simpler walls with little peptidoglycan

b. Simpler walls with lots of peptidoglycan

c. Complex walls with less peptidoglycan and a toxic outer membrane

d. Lack of peptidoglycan entirely

c. Complex walls with less peptidoglycan and a toxic outer membrane

What are endospores in prokaryotes?

a. Structures for sticking to surfaces

b. Metabolically inactive forms that remain viable in harsh conditions

c. Structures for exchanging DNA

d. Protein-rich layers for protection

b. Metabolically inactive forms that remain viable in harsh conditions

How long can prokaryotic endospores remain viable in harsh conditions?

a. A few weeks

b. A few months

c. Centuries

d. A few days

c. Centuries

What function do fimbriae serve in prokaryotes?

a. Allow prokaryotes to exchange DNA

b. Protect against toxins in harsh conditions

c. Help them stick to a substrate or other individuals

d. Aid in movement

c. Help them stick to a substrate or other individuals

How do fimbriae differ from pili in prokaryotes?

a. Fimbriae are longer than pili

b. Pili are longer than fimbriae

c. Fimbriae are used for DNA exchange, whereas pili are not

d. Pili are only found in certain bacterial species

b. Pili are longer than fimbriae

What is the purpose of pili (or sex pili) in prokaryotes?

a. Allow them to exchange DNA

b. Help them stick to a substrate

c. Provide structural support

d. Protect against environmental stress

a. Allow them to exchange DNA

What does taxis refer to in bacteria?

a. Movement toward a homogeneous environment

b. Movement in response to environmental stimuli

c. Stationary behavior in a colony

d. Reproduction in stressful conditions

b. Movement in response to environmental stimuli

What is chemotaxis in bacteria?

a. Movement toward or away from a chemical stimulus

b. Stationary response to chemical changes

c. DNA exchange in response to toxins

d. Reproduction triggered by chemicals

a. Movement toward or away from a chemical stimulus

Which structure is responsible for movement in bacteria?

a. Fimbriae

b. Pili

c. Flagella

d. Endospores

c. Flagella

How do bacteria respond to a heterogeneous environment?

a. They become dormant

b. They exhibit taxis

c. They form colonies exclusively

d. They lose mobility

b. They exhibit taxis

How does the prokaryotic genome compare to the eukaryotic genome?

a. It has more DNA

b. It has less DNA

c. It has the same amount of DNA

d. It lacks DNA entirely

b. It has less DNA

Where is the chromosome located in prokaryotic cells?

a. Surrounded by a membrane

b. In the nucleus

c. In the nucleoid region

d. In the cytoplasm exclusively

c. In the nucleoid region

What is the structure of most prokaryotic chromosomes?

a. Linear

b. Circular

c. Branched

d. Spiral

b. Circular

What are the smaller rings of DNA found in some bacteria called?

a. Chromosomes

b. Nucleoids

c. Ribosomes

d. Plasmids

d. Plasmids

What is a key feature of prokaryotic reproduction?

a. They reproduce sexually by binary fission

b. They reproduce asexually by binary fission

c. They reproduce asexually by meiosis

d. They reproduce exclusively through genetic recombination

b. They reproduce asexually by binary fission

Why do prokaryotes have short generation times?

a. Because they reproduce slowly

b. Because they have rapid reproduction

c. Because they undergo mutations frequently

d. Because they rely on conjugation

b. Because they have rapid reproduction

What contributes to genetic diversity in prokaryotes?

a. Slow reproduction

b. Mutation only

c. Rapid reproduction, mutations, and genetic recombination

d. Genetic recombination exclusively

c. Rapid reproduction, mutations, and genetic recombination

What are examples of genetic recombination mechanisms in prokaryotes?

a. Binary fission, transduction, and transformation

b. Transformation, transduction, and conjugation

c. Conjugation, binary fission, and mutation

d. Mutation and binary fission

b. Transformation, transduction, and conjugation

What is transformation in bacteria?

a. The uptake of DNA through cell-to-cell contact

b. The uptake of exogenous DNA from the surrounding environment

c. Virus-mediated DNA transfer between bacteria

d. Mutation-driven DNA changes

b. The uptake of exogenous DNA from the surrounding environment

What is transduction in bacteria?

a. The uptake of exogenous DNA from the surrounding environment

b. Virus-mediated transfer of DNA between bacteria

c. The transfer of DNA through binary fission

d. DNA recombination through conjugation

b. Virus-mediated transfer of DNA between bacteria

What is conjugation in bacteria?

a. The uptake of exogenous DNA from the surrounding environment

b. Virus-mediated transfer of DNA between bacteria

c. The transfer of DNA from one bacterium to another via cell-to-cell contact

d. DNA replication through rapid reproduction

c. The transfer of DNA from one bacterium to another via cell-to-cell contact

What do halophiles, thermophiles, and methanogens have in common?

a. They are types of bacteria

b. They are types of Archaea

c. They are types of fungi

d. They are types of viruses

b. They are types of Archaea

What are extremophiles?

a. Organisms that thrive in extreme environments

b. Organisms that thrive only in low temperatures

c. Organisms that thrive exclusively in acidic environments

d. Organisms that thrive in moderate environments

a. Organisms that thrive in extreme environments

Where do halophiles thrive?

a. In environments with high oxygen concentration

b. In environments with high salt concentrations

c. In environments with high pressure

d. In environments with high methane levels

b. In environments with high salt concentrations

What are thermophiles capable of?

a. Thriving in high salt concentrations

b. Growing, carrying out metabolic processes, and reproducing at extreme temperatures (140 to 180°F)

c. Living in swamps and producing oxygen as a waste product

d. Being strict anaerobes, poisoned by O2

b. Growing, carrying out metabolic processes, and reproducing at extreme temperatures (140 to 180°F)

Where do methanogens typically live?

a. In deserts

b. In environments with high salt concentrations

c. In swamps and marshes where they produce methane as a waste product

d. In environments with high oxygen levels

c. In swamps and marshes where they produce methane as a waste product

What is a key feature of methanogens?

a. They thrive on oxygen

b. They are strict anaerobes and poisoned by O2

c. They thrive in environments with low methane levels

d. They carry out photosynthesis

b. They are strict anaerobes and poisoned by O2

What role do prokaryotes play in ecosystems?

a. Recycling chemical elements between living and nonliving components of ecosystems

b. Only increasing potassium levels in soil

c. Breaking down minerals exclusively

d. Serving as primary producers in ecosystems

a. Recycling chemical elements between living and nonliving components of ecosystems

Which of the following describes decomposers?

a. Organisms that form symbiotic relationships with plants

b. Organisms that produce methane

c. Organisms that break down dead organisms and waste products

d. Organisms that increase oxygen levels

c. Organisms that break down dead organisms and waste products

How can prokaryotes benefit plant growth?

a. By breaking down dead leaves

b. By increasing nitrogen, phosphorus, and potassium levels

c. By forming fungal spores

d. By absorbing sunlight

b. By increasing nitrogen, phosphorus, and potassium levels

What is bioremediation?

a. Use of organisms to recycle nutrients

b. Use of organisms to remove pollutants from the environment

c. Use of organisms to provide oxygen

d. Use of organisms to increase salt levels

b. Use of organisms to remove pollutants from the environment

What type of relationship can prokaryotes form with larger organisms?

a. Competitive relationships

b. Symbiotic relationships

c. Predator-prey relationships

d. Parasitic relationships

b. Symbiotic relationships