Concept explainers
Choose the phrase from the right column that best fits the term in the left column.
a. transformations | 1. requires supplements in medium for growth |
b. conjugation | 2. a method for mutagenizing genes in bacterial genomes |
c. transduction | 3. small circular DNA molecule that can integrate into the chromosome |
d. lytic cycle | 4. the core genes that define a bacterial species plus all of the genes unique to individual strains |
e.lysogeny | 5. transfer of DNA requiring direct physical contact |
f. episome | 6. integration of phage DNA into the chromosome |
g. auxotroph | 7. infection by phages in which lysis of cells releases new virus particles |
h. pangenome | 8. transfer of naked DNA |
i. gene targeting | 9. transfer of DNA between bacteria via virus particles |
a.
To determine:
The phrase that describes “transformation.”
Answer to Problem 1P
Correct answer:
Transformation: transfer of naked DNA.
Explanation of Solution
Transformation is the process by which the bacterium transforms into another by receiving the naked DNA molecule. This process does not require physical contact like conjugation or virus particles like transduction.
b.
To determine:
The phrase that describes “conjugation.”
Answer to Problem 1P
Correct answer:
Conjugation: transfer of DNA requiring direct physical contact.
Explanation of Solution
Conjugation is the process by which the donor bacterium forms a conjugation tube and then transfers the DNA through this tube into the recipient bacterium. A conjugation is a form of sexual reproduction that takes place in the higher eukaryotes.
c.
To determine:
The phrase that describes “transduction.”
Answer to Problem 1P
Correct answer:
Transduction: transfer of DNA between bacteria via virus particles.
Explanation of Solution
Transduction is the process the transfer of the bacterial DNA takes place through virus particles also known as a bacteriophage, which attacks the bacteria and carries it’s DNA and then integrates this DNA into another bacterium while causing infection.
d.
To determine:
The phrase that describes “lytic cycle”.
Answer to Problem 1P
Correct answer:
Lytic cycle: infection by phages in which lysis of cells releases new particles.
Explanation of Solution
The bacteriophage is the virus that attacks bacteria, hence named bacteriophage. The term phage implies ‘to eat,’ thus bacteriophage means ‘eating bacteria.’ The bacteriophage performs two types of life cycle inside the host. The latent or lysogenic cycle and the virulent lytic cycle.
e.
To determine:
The phrase that describes “lysogeny.”
Answer to Problem 1P
Correct answer:
Lysogeny: integration of phage DNA into the chromosome.
Explanation of Solution
Lysogeny is another form of the viral life cycle in which it does not kill the host buts integrates its DNA inside the host’s DNA and then replicates, causing latent infection. The lysogenic bacteria can be converted into lytic bacteria through some external agents.
f.
To determine:
The phrase that describes “episome.”
Answer to Problem 1P
Correct answer:
Episome: small circular DNA molecule that can integrate into the chromosome.
Explanation of Solution
Episomes are the small circular DNA fragments like plasmid that can replicate on their own and can also integrate into the chromosomes and then replaced along with the chromosomes.
g.
To determine:
The phrase that describes “auxotroph”.
Answer to Problem 1P
Correct answer:
Auxotroph: requires supplements in medium for growth.
Explanation of Solution
Auxotrophs are the special type of organisms that require a certain type of nutrients in the medium from an external source as they cannot synthesize the substrate or enzyme and require it for their proper growth and multiplication. These microbes are used to test the importance of specific substrates in growth and reproduction.
h.
To determine:
The phrase that describes “pangenome.”
Answer to Problem 1P
Correct answer:
Pangenome: the core genes that define a bacterial species plus all of the genes unique to individual strains.
Explanation of Solution
The pangenome is the entire genetic material of an organism. It consists of diploid content of the genome and all the genes that are unique to that specific organism. Hence, it represents the genetic composition of the entire species of an organism.
i.
To determine:
The phrase that describes “gene targeting.”
Answer to Problem 1P
Correct answer:
Gene targeting: a method for mutagenizing genes in bacterial genomes.
Explanation of Solution
Gene targeting is the method of bringing about changes in the gene of the desired organism. This technique belongs to the field of DNA recombinant technology and is used to remove the defective genes or incorporate desired genes inside the DNA and then improve the variety of existing species.
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Chapter 14 Solutions
Genetics: From Genes to Genomes
- Conjugation involves which of the following: a. transfer of plasmids among bacteria b. sexual reproduction of Eukaryotes c. uptake of free DNA from the environment d. integration of a virus into a chromosomearrow_forwardDefine the following terms: a. nonreplicative transposition b. transposable element c. bacterial transformation d. transduction e. conjugationarrow_forwardAlfred Hershey and Martha Chase performed experiments to show that A: the genetic material was DNA contained in the bacteriophage, which entered bacteria during phage infection. B:the genetic material was RNA contained in the bacteriophage, which entered bacteria during phage infection C:the genetic material was protein contained in the bacteriophage, which entered bacteria during phage infection D:none of these choices are correctHomework question i am lost onarrow_forward
- Section two. Match horizontal gene transfer mechanism with best definition. Answers are used more than once. а. Transduction b. Transformation Conjugation c. 44. requires two live cells, where the recipient receives donor DNA 45. involves a virus 46. usually a plasmid is transferred 47. does not require a virus or another cell 48. "sex" for bacteria 49. occurs because of mistake made in chromos ome packaging by a virus 50. Frederick Griffith coined this term.arrow_forwardDefine the following terms: a. lytic cycle b. prophage c. transduction d. lysogeny e. nuclocapsidarrow_forwardThe figure above shows a schematic of genes and transcription control elements from phage λ. Use this figure as an aid to help you describe the molecular events involved in: a) The establishment of lysogeny b) The establishment of a lytic life cyclearrow_forward
- Choose the one answer that fits best. Which of the following statements regarding bacteria is NOT correct? a. During conjugation, two bacteria exchange genetic information directly via pili b. Bacterial populations have a higher mutation rate because their DNA Polymerases do not have proofreading capability c. Bacterial growth by binary fission is exponential and each division usually takes only a couple of hour or less d. Plasmids carry just a few genes and are replicated independently from the bacterial chromosome e. Cocci that are arranged in clusters/bunches are called staphylococciarrow_forwardGenetic information can be transferred horizontally from one bacterial cell to another cell of the "same generation" (versus daughter cells), leading to genetic recombination, by all of the following EXCEPT: A. Gene expression (transcription/translation/protein synthesis) B. Transformation C. Conjugation D. Transduction E. None of the other four answers (all are mechanisms of “horizontal transfer” genetic recombination)arrow_forwardOne of the reasons why phage therapy has not been applied widely is that bacteria can become resistant to bacteriophages as well, through mutations in genes encoding for specific proteins. What would be a protein in the bacterial cell that, if mutated, would make that cell resistant to phage infection?arrow_forward
- In a genetics lab, Kim and Maria infected a samplefrom an E. coli culture with a particular virulent bacteriophage. They noticed that most of the cells werelysed, but a few survived. The survival rate in theirsample was about 1 × 10−4. Kim was sure the bacteriophage induced the resistance in the cells, whileMaria thought that resistant mutants probably alreadyexisted in the sample of cells they used. Earlier, for adifferent experiment, they had spread a dilute suspension of E. coli onto solid medium in a large petri dish,and, after seeing that about 105colonies were growingup, they had replica-plated that plate onto three otherplates. Kim and Maria decide to use these plates totest their theories. They pipette a suspension of thebacteriophage onto each of the three replica plates.What should they see if Kim is right? What shouldthey see if Maria is right?arrow_forwardBriefly discuss the following questions in 3 to 5 sentences. What is horizontal gene transfer? What are the three mechanisms for this to occur in bacteria? What are the components needed for the processes of transformation, conjugation, and transduction? How does each process occur? What genes are involved in each process? How do generalized and specialized transduction differ? What is the end result of each? What is recombination? What is the importance to bacteria & archaea? What are the two types of recombination? What are the details of each type? What components are needed for each type?arrow_forwardBacterial conjugation has medical consequences. For example, certain plasmids contain genes that code for toxins. The causative agent of a deadly form of food poisoning, E. coli 0157, synthesizes a toxin that causes massive bloody diarrhea and kidney failure. This toxin is now believed to have originated in Shigella, another bacterium that causes dysentery. Similarly, the growing problem of antibiotic resistance is partly attributable to the spread of antibioticresistant genes among bacterial populations. Antibiotic resistance develops because antibiotics are overused in medical practice and in livestock feeds. Suggest a mechanism by which this extensive use promotes antibiotic resistance.arrow_forward
- Biology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage Learning