I'm swimming in what? and binary fission
In addition to physical requirements, bacterial growth and multiplication also entails chemical requirements. Which of the following statements would accurately describe chemical requirements and conditions associated with growth in the Lake of the Ozarks environment?
- Fecal coliforms will need to acquire trace elements for growth in the lake environment. - Fecal coliforms will likely contain enzymes to counteract toxic oxygen forms. - The lake environment will support the growth of facultative anaerobes.
The Lake of the Ozarks is a human-made lake, so it collects runoff from coal strip-mining, fertilizers, resort wastewaters, and septic drainages. The average lake temperature is between 10∘∘C and 21∘∘C. Consider the physical requirements for growth and multiplication that would allow fecal coliforms to "blossom" in the Lake of the Ozarks. Which of the following would accurately describe these organisms?
- Psychrophiles - Facultative halophiles - Mesophiles
Steps of bacterial replication in the correct order, starting from a parent cell. (binary fission)
- chromosome replication - cell elongation - septum forming - separation of daughter cells
Which of the following statements regarding infections involving biofilms is true?
-The majority of hospital acquired infections (nosocomial infections) are related to biofilms. -It is estimated that nearly 70% of all infections are caused by biofilms. -Microbes in biofilms are 1000x more resistant to antimicrobials than are independent organisms.
Which biosafety level (BSL) is appropriate for handling organisms that present a moderate risk of infection?
BSL-2 (BSL-2 labs work with organisms that pose a moderate risk of infection. Lab workers in a BSL-2 lab are required to wear lab coats, gloves, and eye protection.)
How long does it take for the daughter cells to initiate or start the next round of replication?
No time is required -- they are ready to divide immediately after DNA replication and separation of the daughter cells is complete if conditions are right..
What enables the copied chromosomes to separate during binary fission?
The chromosomes are attached to different parts of cell membrane, which elongates and thus separates the chromosomes.
What would happen if the septum did not form during binary fission?
The parent cell would now have two copies of the chromosome.
Which of the following statements regarding infections involving biofilms is FALSE?
There is no way to prevent biofilms from developing on surfaces.
Starting with three cells, how many cells would result from three rounds of replication?
Twenty-four
what do not need to dissolve the bacteria?
a nuclear membrane or assemble a mitotic spindle.
Bacteria naturally prefer company instead of solitude for growth. Examples of this kind of communal growth pattern can be found everywhere, from surfaces of the teeth and the intestines, to the surface of a slimy rock in the lake, to the thick floc that clogs water pipes. These examples of communal bacterial growth are known by what name?
biofilm
Sampling lake water for microscopic organisms is not as easy as it sounds when you want to both count and identify species. In a given water sample, your bacteria of choice can be rare or difficult to culture, particularly given the mixture of bacteria in a biofilm. Which of the following culture media would be best for growing fecal coliforms when they are relatively less abundant than other bacteria in the lake?
enrichment culture medium
Bacteria that can grow in the presence or absence of oxygen (O2) are called
facultative anaerobes
Cultures of the Lake of the Ozarks water samples were grown on enrichment media for identification. However, these organisms are present to some degree in all samples. An important question from a clinical perspective is whether or not there is a significant increase in the fecal coliform populations that would put people's health at risk. If you were part of the team investigating this outbreak, how would you best enumerate the fecal coliform threat?
filtration count culture
The chemical requirements for microbial growth include carbon, nitrogen, phosphorus, and sulfur. Why do all cells need nitrogen?
for building amino acids, proteins, and nucleic acids
Salts and sugars work to preserve foods by creating a
hypertonic environment.
Microbes have very narrow optimum temperature ranges. Which of the following classifications of microbes are most likely to cause human disease, based on their temperature requirements?
mesophiles
Which process is best for the short-term storage of bacterial cultures?
refrigeration