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New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.
Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.
Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.
To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.
The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.
Q.
It can be inferred from the passage that the replica plating method is effective for which of the following reasons?
Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.
Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.
To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.
The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.
Q.
It can be inferred from the passage that the replica plating method is effective for which of the following reasons?
- a)It allows researchers to determine the relative sizes of different populations of bacteria.
- b)It shows that no new mutant strains developed after transfer from the original agar plate.
- c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.
- d)It demonstrates that no tryptophan was present in the original agar culture.
- e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
New research by Paul Fildes and K. Whitaker challenges the theory that...
The replica plating method is discussed in the third paragraph. The first two sentences describe the process, while the third sentence explains what was learned by using this method. The correct inference about the effectiveness of the replica plating method will be a virtual rephrasing of the facts presented in the third paragraph.
(A) We cannot infer that the replica plating method allows researchers to determine the relative sizes of different populations of bacteria. The population sizes of various bacteria populations were never discussed.
(B) CORRECT. The last sentence of the passage states that “the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate,” citing this as proof that “the mutants were in fact genetically present or preadapted.” In other words, the mutant strains did not develop after transfer from the original agar plate.
(C) The only type of bacteria mentioned in the passage was bacteria typhosum, so we cannot infer that the replica plating method eliminates the possibility that the agar culture was contaminated by a different type of bacteria.
(D) The role of tryptophan is discussed in the first and second paragraphs. This answer choice goes too far by asserting that “no tryptophan was present in the original agar culture.” We do not have enough information to make that inference.
(E) According to the first paragraph, “the necessary metabolites for bacterial reproduction” are defined as the substances “necessary for their (bacteria’s) regular function.” In the case of bacteria typhosum, that substance is tryptophan. We do not have enough information to infer that the replica plating method establishes that the original agar culture contained tryptophan. If fact, the presence of mutant strains of bacteria on the replica plates would contradict this statement rather than support it.
(A) We cannot infer that the replica plating method allows researchers to determine the relative sizes of different populations of bacteria. The population sizes of various bacteria populations were never discussed.
(B) CORRECT. The last sentence of the passage states that “the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate,” citing this as proof that “the mutants were in fact genetically present or preadapted.” In other words, the mutant strains did not develop after transfer from the original agar plate.
(C) The only type of bacteria mentioned in the passage was bacteria typhosum, so we cannot infer that the replica plating method eliminates the possibility that the agar culture was contaminated by a different type of bacteria.
(D) The role of tryptophan is discussed in the first and second paragraphs. This answer choice goes too far by asserting that “no tryptophan was present in the original agar culture.” We do not have enough information to make that inference.
(E) According to the first paragraph, “the necessary metabolites for bacterial reproduction” are defined as the substances “necessary for their (bacteria’s) regular function.” In the case of bacteria typhosum, that substance is tryptophan. We do not have enough information to infer that the replica plating method establishes that the original agar culture contained tryptophan. If fact, the presence of mutant strains of bacteria on the replica plates would contradict this statement rather than support it.
Most Upvoted Answer
New research by Paul Fildes and K. Whitaker challenges the theory that...
Understanding the Replica Plating Method
The effectiveness of the replica plating method used by Fildes and Whitaker can be inferred from its ability to demonstrate that no new mutant strains developed after the transfer from the original agar plate. Here’s how:
Key Reasons for Effectiveness
- Transfer of Growth Patterns: The replica plating technique allowed researchers to imprint the growth patterns from the original agar plate onto new plates. This direct transfer means that if the mutants were not present in the original sample, they would not appear in the replicas.
- Identical Locations: The mutants found on the replica plates were located in the same positions as on the original plate. This consistency indicates that the mutants were already part of the original culture and were not formed due to environmental conditions or the transfer process.
- Genetic Origin Confirmation: By demonstrating that the mutants were present in both the original and replica plates, Fildes and Whitaker confirmed that these mutant strains existed genetically prior to the experiment, negating the theory of environmental training.
Implications of the Findings
- No New Mutants: The results imply that the experimental conditions did not induce new mutations. Instead, the mutants were pre-existing, showing that the concentration of tryptophan or growth conditions did not lead to the emergence of new strains.
- Challenges Previous Theories: This evidence undermines the previous assumption about training bacteria to mutate by environmental stressors, reinforcing the genetic basis of the mutants' appearance.
In conclusion, option 'B' accurately reflects the core finding that no new mutant strains developed as a result of the transfer, underscoring the genetic stability of the bacterial populations.
The effectiveness of the replica plating method used by Fildes and Whitaker can be inferred from its ability to demonstrate that no new mutant strains developed after the transfer from the original agar plate. Here’s how:
Key Reasons for Effectiveness
- Transfer of Growth Patterns: The replica plating technique allowed researchers to imprint the growth patterns from the original agar plate onto new plates. This direct transfer means that if the mutants were not present in the original sample, they would not appear in the replicas.
- Identical Locations: The mutants found on the replica plates were located in the same positions as on the original plate. This consistency indicates that the mutants were already part of the original culture and were not formed due to environmental conditions or the transfer process.
- Genetic Origin Confirmation: By demonstrating that the mutants were present in both the original and replica plates, Fildes and Whitaker confirmed that these mutant strains existed genetically prior to the experiment, negating the theory of environmental training.
Implications of the Findings
- No New Mutants: The results imply that the experimental conditions did not induce new mutations. Instead, the mutants were pre-existing, showing that the concentration of tryptophan or growth conditions did not lead to the emergence of new strains.
- Challenges Previous Theories: This evidence undermines the previous assumption about training bacteria to mutate by environmental stressors, reinforcing the genetic basis of the mutants' appearance.
In conclusion, option 'B' accurately reflects the core finding that no new mutant strains developed as a result of the transfer, underscoring the genetic stability of the bacterial populations.
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Question Description
New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? for GMAT 2025 is part of GMAT preparation. The Question and answers have been prepared according to the GMAT exam syllabus. Information about New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for GMAT 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer?.
New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? for GMAT 2025 is part of GMAT preparation. The Question and answers have been prepared according to the GMAT exam syllabus. Information about New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for GMAT 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer?.
Solutions for New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for GMAT.
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Here you can find the meaning of New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer?, a detailed solution for New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria.Rather, these mutants were already present in the original sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains, they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments, Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found on an original agar plate to a series of replica agar plates.The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations of the mutant strains on the original agar plate.Q.It can be inferred from the passage that the replica plating method is effective for which of the following reasons?a)It allows researchers to determine the relative sizes of different populations of bacteria.b)It shows that no new mutant strains developed after transfer from the original agar plate.c)It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.d)It demonstrates that no tryptophan was present in the original agar culture.e)It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.Correct answer is option 'B'. Can you explain this answer? tests, examples and also practice GMAT tests.
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