romikgosai/squad_modified huggingface dataset:
In ordinary circumstances, transduction, conjugation, and transformation involve transfer of DNA between individual bacteria of the same species, but occasionally transfer may occur between individuals of different bacterial species and this may have significant consequences, such as the transfer of antibiotic resistance. In such cases, gene acquisition from other bacteria or the environment is called horizontal gene transfer and may be common under natural conditions. Gene transfer is particularly important in antibiotic resistance as it allows the rapid transfer of resistance genes between different pathogens.

Questions and answers:
['
Q: Between what species do usually transduction, conjugation and transformation take place?
A: the same species', '
Q: What are the consequences of transfer between different species of bacteria?
A: transfer of antibiotic resistance', '
Q: What is horizontal gene transfer?
A: gene acquisition from other bacteria or the environment']
Bacteriophages are viruses that infect bacteria. Many types of bacteriophage exist, some simply infect and lyse their host bacteria, while others insert into the bacterial chromosome. A bacteriophage can contain genes that contribute to its host's phenotype: for example, in the evolution of Escherichia coli O157:H7 and Clostridium botulinum, the toxin genes in an integrated phage converted a harmless ancestral bacterium into a lethal pathogen. Bacteria resist phage infection through restriction modification systems that degrade foreign DNA, and a system that uses CRISPR sequences to retain fragments of the genomes of phage that the bacteria have come into contact with in the past, which allows them to block virus replication through a form of RNA interference. This CRISPR system provides bacteria with acquired immunity to infection.

Questions and answers:
['
Q: What are Bacteriophages?
A: viruses that infect bacteria', '
Q: What can viruses do to bacteria?
A: infect and lyse their host bacteria', "
Q: What can happen if Bacteriophage contain genes of host's phenotype?
A: lethal pathogen", '
Q: How can bacteria resist virus DNA?
A: CRISPR system provides bacteria with acquired immunity']
Bacterial species differ in the number and arrangement of flagella on their surface; some have a single flagellum (monotrichous), a flagellum at each end (amphitrichous), clusters of flagella at the poles of the cell (lophotrichous), while others have flagella distributed over the entire surface of the cell (peritrichous). The bacterial flagella is the best-understood motility structure in any organism and is made of about 20 proteins, with approximately another 30 proteins required for its regulation and assembly. The flagellum is a rotating structure driven by a reversible motor at the base that uses the electrochemical gradient across the membrane for power. This motor drives the motion of the filament, which acts as a propeller.

Questions and answers:
['
Q: What is monotrichous?
A: single flagellum', '
Q: How many proteins is typical flagellum consist os?
A: 20 proteins', '
Q: When flagellum is distributed throughout the surface of the cell?
A: peritrichous', '
Q: If bacteria has flagellum at each end what is the name of the species?
A: amphitrichous', '
Q: How does flagellum function within the cell?
A: uses the electrochemical gradient across the membrane']
Classification seeks to describe the diversity of bacterial species by naming and grouping organisms based on similarities. Bacteria can be classified on the basis of cell structure, cellular metabolism or on differences in cell components, such as DNA, fatty acids, pigments, antigens and quinones. While these schemes allowed the identification and classification of bacterial strains, it was unclear whether these differences represented variation between distinct species or between strains of the same species. This uncertainty was due to the lack of distinctive structures in most bacteria, as well as lateral gene transfer between unrelated species. Due to lateral gene transfer, some closely related bacteria can have very different morphologies and metabolisms. To overcome this uncertainty, modern bacterial classification emphasizes molecular systematics, using genetic techniques such as guanine cytosine ratio determination, genome-genome hybridization, as well as sequencing genes that have not undergone extensive lateral gene transfer, such as the rRNA gene. Classification of bacteria is determined by publication in the International Journal of Systematic Bacteriology, and Bergey's Manual of Systematic Bacteriology. The International Committee on Systematic Bacteriology (ICSB) maintains international rules for the naming of bacteria and taxonomic categories and for the ranking of them in the International Code of Nomenclature of Bacteria.

Questions and answers:
['
Q: How can we classify the vast variety of bacterial species?
A: grouping organisms based on similarities', '
Q: Can classification be helpful in determining differences between distinct species?
A: unclear', '
Q: What supports the uncertainty in classification between the same kind of bacteria?
A: lack of distinctive structures in most bacteria,', '
Q: What can lateral gene transfer create in bacteria?
A: different morphologies and metabolisms', '
Q: What is the way modern classification tries to determine species?
A: emphasizes molecular systematics']
The term "bacteria" was traditionally applied to all microscopic, single-cell prokaryotes. However, molecular systematics showed prokaryotic life to consist of two separate domains, originally called Eubacteria and Archaebacteria, but now called Bacteria and Archaea that evolved independently from an ancient common ancestor. The archaea and eukaryotes are more closely related to each other than either is to the bacteria. These two domains, along with Eukarya, are the basis of the three-domain system, which is currently the most widely used classification system in microbiolology. However, due to the relatively recent introduction of molecular systematics and a rapid increase in the number of genome sequences that are available, bacterial classification remains a changing and expanding field. For example, a few biologists argue that the Archaea and Eukaryotes evolved from Gram-positive bacteria.

Questions and answers:
['
Q: What would original term "bacteria" determine?
A: all microscopic, single-cell prokaryotes', '
Q: What are two main groups of prokaryotic organisms are divided into?
A: Eubacteria and Archaebacteria', '
Q: What groups of organisms are closely related to each other?
A: archaea and eukaryotes', '
Q: What domain system is commonly used nowdays to classify microorganisms?
A: three-domain system']
The Gram stain, developed in 1884 by Hans Christian Gram, characterises bacteria based on the structural characteristics of their cell walls. The thick layers of peptidoglycan in the "Gram-positive" cell wall stain purple, while the thin "Gram-negative" cell wall appears pink. By combining morphology and Gram-staining, most bacteria can be classified as belonging to one of four groups (Gram-positive cocci, Gram-positive bacilli, Gram-negative cocci and Gram-negative bacilli). Some organisms are best identified by stains other than the Gram stain, particularly mycobacteria or Nocardia, which show acid-fastness on Ziehl–Neelsen or similar stains. Other organisms may need to be identified by their growth in special media, or by other techniques, such as serology.

Questions and answers:
['
Q: What was developed by Hans Christian  Gram?
A: The Gram stain', '
Q: What year was the Grahm stain was developed?
A: 1884', '
Q: What color do Gram positive bacteria cell walls turn to after being stained?
A: purple', '
Q: What color is typical for Gram-negative bacteria after staining?
A: pink', '
Q: What stain shows better test results on Norcadia bacteria?
A: Ziehl–Neelsen']
As with bacterial classification, identification of bacteria is increasingly using molecular methods. Diagnostics using DNA-based tools, such as polymerase chain reaction, are increasingly popular due to their specificity and speed, compared to culture-based methods. These methods also allow the detection and identification of "viable but nonculturable" cells that are metabolically active but non-dividing. However, even using these improved methods, the total number of bacterial species is not known and cannot even be estimated with any certainty. Following present classification, there are a little less than 9,300 known species of prokaryotes, which includes bacteria and archaea; but attempts to estimate the true number of bacterial diversity have ranged from 107 to 109 total species – and even these diverse estimates may be off by many orders of magnitude.

Questions and answers:
['
Q: What technique has becoming more popular in classification of bacteria?
A: molecular methods', '
Q: What tool does DNA based diagnostics use?
A: polymerase chain reaction', '
Q: What else can molecular methods of classification reveal?
A: identification of "viable but nonculturable" cells', '
Q: Can new methods determine a total number of bacteria species?
A: cannot even be estimated with any certainty']
Some species of bacteria kill and then consume other microorganisms, these species are called predatory bacteria. These include organisms such as Myxococcus xanthus, which forms swarms of cells that kill and digest any bacteria they encounter. Other bacterial predators either attach to their prey in order to digest them and absorb nutrients, such as Vampirovibrio chlorellavorus, or invade another cell and multiply inside the cytosol, such as Daptobacter. These predatory bacteria are thought to have evolved from saprophages that consumed dead microorganisms, through adaptations that allowed them to entrap and kill other organisms.

Questions and answers:
['
Q: Why are certain bacteria called predatory?
A: bacteria kill and then consume other microorganisms', '
Q: Which way do Vampirovibrio absorb nutrients of other microorganisms?
A: attach to their prey in order to digest them', '
Q: What technique do Daptobacter use in order to kill other microorganism?
A: invade another cell and multiply inside the cytosol', '
Q: Where do Daptobacter bacteria come from?
A: saprophages']
Certain bacteria form close spatial associations that are essential for their survival. One such mutualistic association, called interspecies hydrogen transfer, occurs between clusters of anaerobic bacteria that consume organic acids, such as butyric acid or propionic acid, and produce hydrogen, and methanogenic Archaea that consume hydrogen. The bacteria in this association are unable to consume the organic acids as this reaction produces hydrogen that accumulates in their surroundings. Only the intimate association with the hydrogen-consuming Archaea keeps the hydrogen concentration low enough to allow the bacteria to grow.

Questions and answers:
['
Q: What helps bacteria to survive?
A: close spatial associations', '
Q: What kind of bacteria can form interspecies hydrogen transfer?
A: anaerobic bacteria', '
Q: What do anaerobic bacteria consume?
A: butyric acid or propionic acid']
In soil, microorganisms that reside in the rhizosphere (a zone that includes the root surface and the soil that adheres to the root after gentle shaking) carry out nitrogen fixation, converting nitrogen gas to nitrogenous compounds. This serves to provide an easily absorbable form of nitrogen for many plants, which cannot fix nitrogen themselves. Many other bacteria are found as symbionts in humans and other organisms. For example, the presence of over 1,000 bacterial species in the normal human gut flora of the intestines can contribute to gut immunity, synthesise vitamins, such as folic acid, vitamin K and biotin, convert sugars to lactic acid (see Lactobacillus), as well as fermenting complex undigestible carbohydrates. The presence of this gut flora also inhibits the growth of potentially pathogenic bacteria (usually through competitive exclusion) and these beneficial bacteria are consequently sold as probiotic dietary supplements.

Questions and answers:
['
Q: Where do bacteria stay in soil?
A: rhizosphere', '
Q: What do bacteria do in soil?
A: converting nitrogen gas to nitrogenous compounds', '
Q: How does the conversion help the vegetation?
A: provide an easily absorbable form of nitrogen', '
Q: What is the amount of bacteria in human intestines?
A: over 1,000 bacterial species', '
Q: How does gut flora prevent growth of pathogenic bacteria?
A: through competitive exclusion']
If bacteria form a parasitic association with other organisms, they are classed as pathogens. Pathogenic bacteria are a major cause of human death and disease and cause infections such as tetanus, typhoid fever, diphtheria, syphilis, cholera, foodborne illness, leprosy and tuberculosis. A pathogenic cause for a known medical disease may only be discovered many years after, as was the case with Helicobacter pylori and peptic ulcer disease. Bacterial diseases are also important in agriculture, with bacteria causing leaf spot, fire blight and wilts in plants, as well as Johne's disease, mastitis, salmonella and anthrax in farm animals.

Questions and answers:
['
Q: What are the pathogenes?
A: bacteria form a parasitic association with other organisms', '
Q: Can cause for most pathogenic diseases be found soon?
A: may only be discovered many years after', '
Q: What can pathogenes cause?
A: human death and disease']
Each species of pathogen has a characteristic spectrum of interactions with its human hosts. Some organisms, such as Staphylococcus or Streptococcus, can cause skin infections, pneumonia, meningitis and even overwhelming sepsis, a systemic inflammatory response producing shock, massive vasodilation and death. Yet these organisms are also part of the normal human flora and usually exist on the skin or in the nose without causing any disease at all. Other organisms invariably cause disease in humans, such as the Rickettsia, which are obligate intracellular parasites able to grow and reproduce only within the cells of other organisms. One species of Rickettsia causes typhus, while another causes Rocky Mountain spotted fever. Chlamydia, another phylum of obligate intracellular parasites, contains species that can cause pneumonia, or urinary tract infection and may be involved in coronary heart disease. Finally, some species, such as Pseudomonas aeruginosa, Burkholderia cenocepacia, and Mycobacterium avium, are opportunistic pathogens and cause disease mainly in people suffering from immunosuppression or cystic fibrosis.

Questions and answers:
["
Q: How pathogenes interact with it's human host?
A: pathogen has a characteristic spectrum of interactions", '
Q: Can all bacteria in human body  be harmful?
A: exist on the skin or in the nose without causing any disease', '
Q: Which bacteria cause Rocky Mountain spotted fever disiease?
A: species of Rickettsia']
Bacterial infections may be treated with antibiotics, which are classified as bacteriocidal if they kill bacteria, or bacteriostatic if they just prevent bacterial growth. There are many types of antibiotics and each class inhibits a process that is different in the pathogen from that found in the host. An example of how antibiotics produce selective toxicity are chloramphenicol and puromycin, which inhibit the bacterial ribosome, but not the structurally different eukaryotic ribosome. Antibiotics are used both in treating human disease and in intensive farming to promote animal growth, where they may be contributing to the rapid development of antibiotic resistance in bacterial populations. Infections can be prevented by antiseptic measures such as sterilizing the skin prior to piercing it with the needle of a syringe, and by proper care of indwelling catheters. Surgical and dental instruments are also sterilized to prevent contamination by bacteria. Disinfectants such as bleach are used to kill bacteria or other pathogens on surfaces to prevent contamination and further reduce the risk of infection.

Questions and answers:
['
Q: What type of antibiotics called bacterocidal?
A: if they kill bacteria', '
Q: What kind of antibiotics are used for prevention of bacterial growth
A: bacteriostatic', '
Q: What is the drawback of using antibiotics if agriculture?
A: rapid development of antibiotic resistance in bacterial populations', '
Q: Besides in treating human disease where else are antibiotics used?
A: in intensive farming to promote animal growth', '
Q: What is common prevention method of infections in medicine?
A: sterilizing']
The ability of bacteria to degrade a variety of organic compounds is remarkable and has been used in waste processing and bioremediation. Bacteria capable of digesting the hydrocarbons in petroleum are often used to clean up oil spills. Fertilizer was added to some of the beaches in Prince William Sound in an attempt to promote the growth of these naturally occurring bacteria after the 1989 Exxon Valdez oil spill. These efforts were effective on beaches that were not too thickly covered in oil. Bacteria are also used for the bioremediation of industrial toxic wastes. In the chemical industry, bacteria are most important in the production of enantiomerically pure chemicals for use as pharmaceuticals or agrichemicals.

Questions and answers:
['
Q: What quality of bacteria is being widely used re-cyling?
A: ability of bacteria to degrade a variety of organic compounds', '
Q: What is being used in cleaning up oil spills?
A: Bacteria', '
Q: What other way is bacteria aiding to nature?
A: used for the bioremediation']
Because of their ability to quickly grow and the relative ease with which they can be manipulated, bacteria are the workhorses for the fields of molecular biology, genetics and biochemistry. By making mutations in bacterial DNA and examining the resulting phenotypes, scientists can determine the function of genes, enzymes and metabolic pathways in bacteria, then apply this knowledge to more complex organisms. This aim of understanding the biochemistry of a cell reaches its most complex expression in the synthesis of huge amounts of enzyme kinetic and gene expression data into mathematical models of entire organisms. This is achievable in some well-studied bacteria, with models of Escherichia coli metabolism now being produced and tested. This understanding of bacterial metabolism and genetics allows the use of biotechnology to bioengineer bacteria for the production of therapeutic proteins, such as insulin, growth factors, or antibodies.

Questions and answers:
['
Q: What sciences use bacteria?
A: molecular biology, genetics and biochemistry']
Bacteria were first observed by the Dutch microscopist Antonie van Leeuwenhoek in 1676, using a single-lens microscope of his own design. He then published his observations in a series of letters to the Royal Society of London. Bacteria were Leeuwenhoek's most remarkable microscopic discovery. They were just at the limit of what his simple lenses could make out and, in one of the most striking hiatuses in the history of science, no one else would see them again for over a century. Only then were his by-then-largely-forgotten observations of bacteria — as opposed to his famous "animalcules" (spermatozoa) — taken seriously.

Questions and answers:
['
Q: When was the first time bacteria were observed?
A: 1676', '
Q: Who discovered bacteria?
A: Dutch microscopist Antonie van Leeuwenhoek', '
Q: How was he able to see bacteria?
A: using a single-lens microscope of his own design', '
Q: How long did it take for his discovery to be taken seriously?
A: over a century']
Though it was known in the nineteenth century that bacteria are the cause of many diseases, no effective antibacterial treatments were available. In 1910, Paul Ehrlich developed the first antibiotic, by changing dyes that selectively stained Treponema pallidum — the spirochaete that causes syphilis — into compounds that selectively killed the pathogen. Ehrlich had been awarded a 1908 Nobel Prize for his work on immunology, and pioneered the use of stains to detect and identify bacteria, with his work being the basis of the Gram stain and the Ziehl–Neelsen stain.

Questions and answers:
['
Q: When was the first antibiotic discovered?
A: In 1910', '
Q: Who was the creator of antibiotic?
A: Paul Ehrlich', '
Q: What bacteria did he treat first?
A: Treponema pallidum', "
Q: Who based their research on Enrlich's stains works?
A: Gram stain and the Ziehl–Neelsen", '
Q: How was his discovery aknowledged?
A: had been awarded a 1908 Nobel Prize']
When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly (PCBA). The IPC preferred term for assembled boards is circuit card assembly (CCA), and for assembled backplanes it is backplane assemblies. The term PCB is used informally both for bare and assembled boards.

Questions and answers:
["
Q: What's the abbreviation for a printed wiring board?
A: PWB", '
Q: What organization likes the term "circuit card assembly" for boards that have already been assembled?
A: IPC', '
Q: What would we call a printed circuit board with embedded electronics, abbreviated PCA?
A: printed circuit assembly', "
Q: What's the more appropriate, but mostly unused, name for a printed circuit board when it doesn't have embedded components?
A: printed wiring board", '
Q: What abbreviation would the IPC use for an assembled circuit board?
A: CCA']
Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints increased efficiency. Traces were made with self-adhesive tape. Pre-printed non-reproducing grids on the mylar assisted in layout. To fabricate the board, the finished photomask was photolithographically reproduced onto a photoresist coating on the blank copper-clad boards.

Questions and answers:
['
Q: In the old PCB design method, what was used to connect component pin pads?
A: traces', '
Q: What did PCB designers used to employ on a mylar sheet?
A: photomask', '
Q: What were traces originally made out of?
A: self-adhesive tape', '
Q: Designers would rub on a dry transfer of what to make the process of laying out components simpler?
A: common component footprints', '
Q: What kind of metal coated the blank boards used to make PCBs?
A: copper']
Panelization is a procedure whereby a number of PCBs are grouped for manufacturing onto a larger board - the panel. Usually a panel consists of a single design but sometimes multiple designs are mixed on a single panel. There are two types of panels: assembly panels - often called arrays - and bare board manufacturing panels. The assemblers often mount components on panels rather than single PCBs because this is efficient. The bare board manufactures always uses panels, not only for efficiency, but because of the requirements the plating process. Thus a manufacturing panel can consist of a grouping of individual PCBs or of arrays, depending on what must be delivered.

Questions and answers:
['
Q: What process groups PCBs before transfer to a panel?
A: Panelization', '
Q: Is it more common for panels to have a single design or many designs?
A: a single design', '
Q: What type of panels can also be referred to as an "array?\'
A: assembly panels', "
Q: What step of the bare board manufacture would be impossible if panels weren't always used?
A: the plating process", "
Q: Besides assembly panels, what's the other type of panel?
A: bare board manufacturing panels"]