Chapter 9 Flashcards
What is Horizontal Gene Transfer?
genes passed between individual members of a different species through non-reproductive mechanisms
How does DNA travel in bacteria?
unidirectional, with no complete diploid stage forms
Traits of bacterial genome
extra chromosome, small, circular
What are the three ways that bacteria receive genetic material?
Conjugation
Transformation
Transduction
What is the plasmid?
extrachromosomal genetic elements that are capable of autonomous replication
What is Conjugation?
unidirectional transfer of genetic material between donor and recipient bacteria cells via direct contact
What are transconjugants?
recipients containing donor DNA
What are Hfr cells (high-frequency cells)?
donor cells with F factor integrated into the donor bacterial chromosome
What are Fâ cells?
cells that contain F plasmid that carry some bacterial genes
What are Merozygotes?
partial diploid bacterial cells containing F plasmid carrying some bacterial genes
How does antibiotic resistance come about?
the action of genes located on R plasmids that can be transferred naturally
What is transformation?
a bacterium takes up DNA from the medium
recombination takes place between introduced genes and the bacterial chromosome
What are transformants?
cells that receive genetic material
What are competent cells?
cells that take up DNA
Definition of cotransformed
cells that are transformed by two or more genes
What is the Competence Factor?
when some bacteria take up DNA, a particular time in their growth cycle when they produce a specific protein called the competence factor
Traits of Transduction
bacteriophage (bacterial viruses) carry DNA from one bacterium to another
Usually occurs between bacteria of the same or closely related species
Traits of virulent phages
reproduce through lytic cycle, always kill host cell
Temperate Phages
inactive prophage DNA integrates into bacterial chromosomes
What is the Lytic Cycle?
phage multiply within the host cell, and release progeny phage
What is the Lysogenic Cycle?
Phage either multiply via the lytic cycle or in a quiescent state in the bacterial cell
What do bacteriophages transfer to bacteria?
genes (T2, 4, 5, 6, 7)
What is a retrovirus?
RNA viruses that have been integrated into the host genome (HIV and AIDS)
What is Reverse Transcriptase?
synthesizing DNA from RNA or DNA template
