Roots obtain oxgyen from air soil for respiration , In the absence or deficiency of `O_(2)` , root growth is restricted or completely stopped. How do the plants growing in marsh lands or swamps obtain their `O_(2)` required for root respiration ?
Roots obtain oxgyen from air soil for respiration , In the absence or deficiency of `O_(2)` , root growth is restricted or completely stopped. How do the plants growing in marsh lands or swamps obtain their `O_(2)` required for root respiration ?
Text Solution
AI Generated Solution
To answer the question about how plants growing in marshlands or swamps obtain the oxygen required for root respiration, we can break down the solution into several steps:
### Step-by-Step Solution:
1. **Understanding Root Respiration**:
- Roots of plants require oxygen (O₂) for respiration, which is essential for their growth and development. In normal conditions, roots obtain oxygen from the air in the soil.
**Hint**: Remember that roots need oxygen for cellular respiration, which is crucial for energy production.
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Roots obtain oxygen from air in the soil for respiration. In the absence or deficiency of oxygen (O_2) , root growth is restricted or completely stopped. How do the plants growing in swamps obtain their oxygen required for root respiration?
Plants do not require O_(2) for respiration and they never give out CO_(2) .
Knowledge Check
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. The first paragraph of Passage 1 primarily serves to
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. The first paragraph of Passage 1 primarily serves to
A
present a claim that is supported and developed over the course of the passage
B
introduce a controversy that the study described in the passage is intended to resolve.
C
identify a problem that the research discussed in the passage may help to address
D
offer a theory that is challenged by the findings presented in the passage
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. The author of Passage 1 suggests that an advantage of the method Lewis’s team used to grow microorganisms is that it
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. The author of Passage 1 suggests that an advantage of the method Lewis’s team used to grow microorganisms is that it
A
identifies the requirements for soil bacteria to thrive and replicates those features in artificial soil.
B
enables soil bacteria to take in more nutrients than they typically consume in natural settings.
C
directly affects the cell walls of bacteria rather than the proteins those bacteria produce.
D
allows researchers to make use of soil bacteria that they had previously been unable to exploit.
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. Which choice provides the best evidence for the answer to the previous question?
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. Which choice provides the best evidence for the answer to the previous question?
A
Lines 17-21 (“But only . . . now”)
B
Lines 28-32 (“To do . . . cells”)
C
Lines 32-34 (“We just . . . says”)
D
Lines 44-47 (“It’s likely . . . organically”)
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Explore conceptually related problems
For his 18th birthday in February Peter plants to turn a hut in the garden of his parents into a swimming pool with an artifical beach. In order to estimate the consts for heating the water and the house , peter obtains the data for the natural gas combustion and its price. What is the total energy (in MJ) needed for Peter's "winter swimming pool" calculated in 1.3 and 1.4? How much natural gas will he need, if the gas heater has an efficiency of 90.0% ? What are the different costs for the use of either natural gas or electricity ? Use the values given by PUC for your calculations and assume 100% efficiency for the electric heater. Table 1: Composition of natural gas {:("Chemical substance","mol fraction x",D_(1)H^(@)(KJ mol^(-1))^(-1),S^(@)(J mol^(-1)K^(-1))^(-1),C_(p)^(@)(J mol^(-1)K^(-1))^(-1)),(CO_(2(g)),0.0024,-393.5,213.6,37.1),(N_(2(g)) ,0.0134,0.0,191.6,29.1),(CH_(2(g)),0.9732,-74.6,186.3,35.7),(C_(2)H_(3 (g)),0.0110,-84.0,229.2,52.2),(H_(2)O_(g),-,-285.8,70.0,75.3),(H_(2)O_(g),-,-241.8,188.8,33.6),(H_(2)O_(g),-,0.0,205.2,29.4):} Equation J=E(A.Deltat)^(-1) =!! lambda "wall" . DeltaT. d^(-1) , where J= energy flow E along a temperature gradient (wall direction Z) par area A and time Deltat , d-wall thickness , lambda wall -heat conductivity , DeltaT - difference in temperature between the inside and the outside of the house.
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. The author of Passage 2 would most likely agree with which statement about the development of teixobactin?
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. As used in line 79, “caveats” most nearly means
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. In the last sentence of Passage 2, the author uses the phrase “five years and £500 million” primarily to
Passage 1 is adapted from Brian Handwerk, “A New Antibiotic Found in Dirt Can Kill Drug-Resistant Bacteria.” ©2015 by Smithsonian Institution. Passage 2 is adapted from David Livermore, “This New Antibiotic Is Cause for Celebration—and Caution.” ©2015 by Telegraph Media Group Limited. Passage 1 “Pathogens are acquiring resistance faster than we can introduce new antibiotics, and this is causing a human health crisis,” says biochemist Kim Lewis of Line Northeastern University. Lewis is part of a team that recently unveiled a promising antibiotic, born from a new way to tap the powers of soil microorganisms. In animal tests, teixobactin proved effective at killing off a wide variety of disease-causing bacteria—even those that have developed immunity to other drugs. The scientists’ best efforts to create mutant bacteria with resistance to the drug failed, meaning teixobactin could function effectively for decades before pathogens naturally evolve resistance to it. Natural microbial substances from soil bacteria and fungi have been at the root of most antibiotic drug development during the past century. But only about one percent of these organisms can be grown in a lab. The rest, in staggering numbers, have remained uncultured and of limited use to medical science, until now. “Instead of trying to figure out the ideal conditions for each and every one of the millions of organisms out there in the environment, to allow them to grow in the lab, we simply grow them in their natural environment where they already have the conditions they need for growth,” Lewis says. To do this, the team designed a gadget that sandwiches a soil sample between two membranes, each perforated with pores that allow molecules like nutrients to diffuse through but don’t allow the passage of cells. “We just use it to trick the bacteria into thinking that they are in their natural environment,” Lewis says. The team isolated 10,000 strains of uncultured soil bacteria and prepared extracts from them that could be tested against nasty pathogenic bacteria. Teixobactin emerged as the most promising drug. Mice infected with bacteria that cause upper respiratory tract infections (including Staphylococcus aureus and Streptococcus pneumoniae) were treated with teixobactin, and the drug knocked out the infections with no noticeable toxic effects. It’s likely that teixobactin is effective because of the way it targets disease: The drug breaks down bacterial cell walls by attacking the lipid molecules that the cell creates organically. Many other antibiotics target the bacteria’s proteins, and the genes that encode those proteins can mutate to produce different structures. Passage 2 Many good antibiotic families—penicillin, streptomycin, tetracycline—come from soil fungi and bacteria and it has long been suspected that, if we could grow more types of bacteria from soil—or from exotic environments, such as deep oceans—then we might find new natural antibiotics. In a recent study, researchers [Kim Lewis and others] found that they could isolate and grow individual soil bacteria—including types that can’t normally be grown in the laboratory—in soil itself, which supplied critical nutrients and minerals. Once the bacteria reached a critical mass they could be transferred to the lab and their cultivation continued. This simple and elegant methodology is their most important finding to my mind, for it opens a gateway to cultivating a wealth of potentially antibioticproducing bacteria that have never been grown before. The first new antibiotic that they’ve found by this approach, teixobactin, from a bacterium called Eleftheria terrae, is less exciting to my mind, though it doesn’t look bad. Teixobactin killed Gram-positive bacteria, such as S. aureus, in the laboratory, and cured experimental infection in mice. It also killed the tuberculosis bacterium, which is important because there is a real problem with resistant tuberculosis in the developing world. It was also difficult to select teixobactin resistance. So, what are my caveats? Well, I see three. First, teixobactin isn’t a potential panacea. It doesn’t kill the Gram-negative opportunists as it is too big to cross their complex cell wall. Secondly, scaling to commercial manufacture will be challenging, since the bacteria making the antibiotic are so difficult to grow. And, thirdly, it’s early days yet. As with any antibiotic, teixobactin now faces the long haul of clinical trials: Phase I to see what dose you can safely give the patient, Phase II to see if it cures infections, and Phase III to compare its efficacy to that of “standard of care treatment.” That’s going to take five years and £500 million and these are numbers we must find ways to reduce (while not compromising safety) if we’re to keep ahead of bacteria, which can evolve far more swiftly and cheaply. Which choice best describes the relationship between Passage 1 and Passage 2 ?
NCERT EXEMPLAR ENGLISH-MORPHOLOGY OF FLOWERING PLANTS-Very Short Answer Type Questions
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03:08
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01:25
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- Which of the following plants parts in garlic and onion are edible ?
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- In epigynous flower , ovary is situated below the ……… .
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- Add the missing floral organs of the given floral formula of Fabaceae.
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- Name the body part modified for food storage in the following {:((a...
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