unit 2 mastering biology
|Select the valid comparison between eukaryotes and prokaryotes.|
Eukaryotes are far more metabolically diverse than prokaryotes.
Prokaryote cells have simpler internal structure and genomic organization than eukaryotic cells.
The total biomass of eukaryotes is approximately ten times the total biomass of prokaryotes.
|Prokaryote cells have simpler internal structure and genomic organization than eukaryotic cells.|
| Identify the thylakoid membrane of the cyanobacterium shown here. |
The thylakoid membrane of the cyanobacterium is a nucleoid membrane.
The thylakoid membrane of the cyanobacterium is a chloroplast membrane.
The thylakoid membrane of the cyanobacterium is an infolded plasma membrane.
|The thylakoid membrane of the cyanobacterium is an infolded plasma membrane.|
| Which of the following processes contributes to genetic recombination in prokaryotes?|
| Approximately how many prokaryotic cells live in 5 mL of fertile soil?|
About 100 million prokaryotic cells
About 10,000 prokaryotic cells
About 10 million prokaryotic cells
|About 100 million prokaryotic cells|
|Select the correct statement about bacteria.|
Certain bacteria live within rocks kilometers below the Earth's surface.
All organisms with cells containing a membrane-enclosed nucleus and organelles are eukaryotes, whereas all organisms with cells lacking a membrane-enclosed nucleus and organelles are bacteria.
The majority of bacteria cause human disease.
|Certain bacteria live within rocks kilometers below the Earth's surface.|
|What is the function of fimbriae?|
They are components of the outer cell wall in gram-negative bacteria.
They are used in motility.
They are used to transfer DNA during conjugation.
They are used to attach the cell to its substrate or to other prokaryotes.
They protect the cell from dehydration.
|They are used to attach the cell to its substrate or to other prokaryotes.|
|How does the large amount of genetic variation observed in prokaryotes arise?|
The mutation rate in prokaryotes is much higher than in eukaryotes.
They have extremely short generation times and large populations.
They can exchange DNA with many types of prokaryotes by way of horizontal gene transfer.
They have a relatively small genome.
The second and third answers are correct.
| The second and third answers are correct.|
( They have extremely short generation times and large populations.
They can exchange DNA with many types of prokaryotes by way of horizontal gene transfer.)
| Genes for the resistance of antibiotics are usually located _____.|
on the outside of the cell wall
on the main chromosome
in eukaryotic cells
|Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are _____.|
|Which statement is true about obligate anaerobes?|
They live exclusively by cellular respiration or by anaerobic respiration.
They will use O2 if it is present, but can obtain energy by fermentation if needed.
They use O2 for cellular respiration and cannot grow without it.
They are poisoned by O2.
They obtain energy by oxidizing ferrous ions.
|They are poisoned by O2.|
| The prokaryotic organisms most likely to be found living in salt ponds are the _____.|
| An ecological relationship between organisms of different species that are in direct contact can best be described as _____.|
| How are archaeans most similar to bacteria?|
the structure of their cell walls
nucleotide sequence of small subunit ribosomal RNA
the occurrence of introns in their chromosomes
the shape of their chromosomes and plasmids
|the shape of their chromosomes and plasmids|
|Which statement about endotoxins is true?|
An example of a prokaryote that produces endotoxins is Clostridium botulinum.
Endotoxins are released only when bacteria die and their cell walls break down.
The source of endotoxins is endospores.
Endotoxins are proteins secreted by prokaryotes.
Endotoxins are components of the cell wall of gram-positive bacteria.
|Endotoxins are released only when bacteria die and their cell walls break down.|
|Bioremediation is _____.|
the use of prokaryotes in producing pharmaceutical products
the use of organisms to remove pollutants from the environment
the use of prokaryotes in producing transgenic organisms
the use of biological processes to remedy diseases
the modification of prokaryotes for industrial purposes
|the use of organisms to remove pollutants from the environment|