Openstax Microbiology - Chapter 3 Exam Questions and Answers Latest Update 2025 Graded A+
prokaryote - Answers prenucleus
eukaryote - Answers true nucleus
Prokaryotic cells - Answers •One circular chromosome, not in a membrane
•No histones
•No organelles
•Bacteria: peptidoglycan cell walls
•Archaea: pseudomurein cell walls
Divides by binary fission
eukaryotic cells - Answers •Paired chromosomes, in nuclear membrane
•Histones
•Organelles
•Polysaccharide cell walls, when present
•Divides by mitosis
Average size of bacterial cells - Answers 0.2 to 2.0 um diameter x 2 to 8 um length
most bacteria are ____________ but a few are ________ - Answers monomorphic; pleomorphic
prokaryote shapes - Answers bacilli, cocci, vibrio, spirillum, spirochete, star-shaped, and rectangular.
Arrangement of bacterial cells - Answers Pairs: diplococci, diplobacilli
Clusters: staphylococci
Chains: streptococci, streptobacilli
Groups of four: tetrads
Cubelike groups of eight: sarcinae
cytoplasm - Answers A jellylike fluid inside the cell in which the organelles are suspended. eighty percent
water plus proteins, carbohydrates, lipids, and ions.
Cytoskeleton - Answers A network of long protein strands in the cytosol that helps support the cell.
microfilaments and intermediate filaments.
, bacterial chromosome - Answers circular thread of DNA that contains the cell's genetic information
plasmids - Answers extrachromosomal genetic elements; carry non-crucial genes (ex. antibiotic
resistance, production of toxins)
Ribosomes - Answers site of protein synthesis. made of protein and ribosomal RNA. 70S (size, 50S+30S
subunits)
inclusions - Answers Chemical substances such as stored nutrients or cell products
types of inclusions - Answers - metachromatic granules (volutin)
- polysaccharide granules
- lipid inclusions
- sulfur granules
- carboxysomes
- gas vacuoles
- magnetosomes
Metachromatic granules (volutin) - Answers phosphate reserves
polysaccharide granules - Answers glycogen and starch energy reserves
lipid inclusions - Answers energy reserves
sulfur granules - Answers energy reserves
Carboxysomes - Answers RuBisCO enzyme for CO2 fixation during photosynthesis
gas vacuoles - Answers protein-covered cylinders that maintain buoyancy
magnetosomes - Answers iron oxide (destroys H2O2)
endospores - Answers produced by resting cells when nutrients are depleted. resistant to desiccation,
heat, chemicals, and radiation. are produced by BACILLUS AND CLOSTRIDIUM
sporulation - Answers formation of endospores
germination - Answers when an endospore returns to its vegetative state.
bacterial cell wall - Answers prevents osmotic lysis and protects the cell membrane, made of
peptidoglycan, and contributes to pathogenicity.
prokaryote - Answers prenucleus
eukaryote - Answers true nucleus
Prokaryotic cells - Answers •One circular chromosome, not in a membrane
•No histones
•No organelles
•Bacteria: peptidoglycan cell walls
•Archaea: pseudomurein cell walls
Divides by binary fission
eukaryotic cells - Answers •Paired chromosomes, in nuclear membrane
•Histones
•Organelles
•Polysaccharide cell walls, when present
•Divides by mitosis
Average size of bacterial cells - Answers 0.2 to 2.0 um diameter x 2 to 8 um length
most bacteria are ____________ but a few are ________ - Answers monomorphic; pleomorphic
prokaryote shapes - Answers bacilli, cocci, vibrio, spirillum, spirochete, star-shaped, and rectangular.
Arrangement of bacterial cells - Answers Pairs: diplococci, diplobacilli
Clusters: staphylococci
Chains: streptococci, streptobacilli
Groups of four: tetrads
Cubelike groups of eight: sarcinae
cytoplasm - Answers A jellylike fluid inside the cell in which the organelles are suspended. eighty percent
water plus proteins, carbohydrates, lipids, and ions.
Cytoskeleton - Answers A network of long protein strands in the cytosol that helps support the cell.
microfilaments and intermediate filaments.
, bacterial chromosome - Answers circular thread of DNA that contains the cell's genetic information
plasmids - Answers extrachromosomal genetic elements; carry non-crucial genes (ex. antibiotic
resistance, production of toxins)
Ribosomes - Answers site of protein synthesis. made of protein and ribosomal RNA. 70S (size, 50S+30S
subunits)
inclusions - Answers Chemical substances such as stored nutrients or cell products
types of inclusions - Answers - metachromatic granules (volutin)
- polysaccharide granules
- lipid inclusions
- sulfur granules
- carboxysomes
- gas vacuoles
- magnetosomes
Metachromatic granules (volutin) - Answers phosphate reserves
polysaccharide granules - Answers glycogen and starch energy reserves
lipid inclusions - Answers energy reserves
sulfur granules - Answers energy reserves
Carboxysomes - Answers RuBisCO enzyme for CO2 fixation during photosynthesis
gas vacuoles - Answers protein-covered cylinders that maintain buoyancy
magnetosomes - Answers iron oxide (destroys H2O2)
endospores - Answers produced by resting cells when nutrients are depleted. resistant to desiccation,
heat, chemicals, and radiation. are produced by BACILLUS AND CLOSTRIDIUM
sporulation - Answers formation of endospores
germination - Answers when an endospore returns to its vegetative state.
bacterial cell wall - Answers prevents osmotic lysis and protects the cell membrane, made of
peptidoglycan, and contributes to pathogenicity.
