Concept explainers
Streptomyces coelicolor has a linear chromosome. Interestingly, there are no genes that encode essential proteins near the ends of the chromosome in this bacterium. Why do you think this is the case?
Streptomyces coelicolor is characterized by a soil-dwelling Gram-positive, filamentous bacterium, which belongs to Streptomyces genus. It is well known for their capability to generate complex secondary metabolites such as antibiotics. It is considered as the best studied Streptomyces strain. Therefore, it becomes a model organism for all Streptomyces species.
Explanation of Solution
Most eukaryotic organisms possess linear chromosomes and their end portions are termed as telomeres. Telomeres comprised of repetitive DNA molecules and lacks genes. During the replication of DNA, since the ends of the linear chromosomes are fragile, some of the DNA telomere is lost. As a result, it is difficult to replicate the DNA ends accurately.
Similarly, the Streptomyces bacteria have linear plasmids and linear chromosomes with terminal inverted repeats. Therefore, the above explained situation is seen in the Streptomyces species.
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Chapter 13 Solutions
Prescott's Microbiology
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- Why are prokaryotes able to replicate so much more quickly than eukaryotes? (Hint: What cellular components must be copied before a cell splits in two?) Why is this difference in replication rate an important part of our vulnerability to bacterial pathogens?arrow_forwardWhy does conjugation occur in bacteria?arrow_forwardBelow is a diagram of the general structure of the bacteriophagel chromosome. Speculate on the mechanism by which it forms aclosed ring upon infection of the host cell. 5'GGGCGGCGACCT:double@stranded region-3' 3'- double@stranded region:CCCGCCGCTGGA5'arrow_forward
- Bacterial cells were coinfected with two types of bacteriophage lambda: One carried the c+ allele and theother the c allele. After the cells lysed, progeny bacteriophage were collected. When a single such progeny bacteriophage was used to infect a new bacterialcell, it was observed in rare cases that some of theresulting phage progeny were c+ and others were c.Explain this result.arrow_forwardConjugation is sometimes called bacterial mating. Is it a form ofsexual reproduction? Explain.arrow_forwardWhat 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_forward
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