extrachromasomal (prokary) gentic Flashcards
What is a transposon?
A plasmid with sequences homologous to a host cell chromosome capable of reverse integration and excision.
B sequence with integrated conjugative plasmids.
C mobile stretch of DNA able to jump from location to another in a cell.
OPTION C
B is a highfrequency of recombnation strain (Hfr)
> these are cells with integrated conguative plasmids, so did not have it in the first place but homologously recombinated - hula hoop
Which of these is not a method by which prokaryotes transfer DNA from cell to cell A Conjugation B Transformation C Binary fission D Transduction
Binary fission is the process by which a prokaryotic cell divides.
Which of these is not a method of DNA repair? Homologous recombination Base excision repair Non-homologous end joining Mismatch repair Homologous end joining
HOMOLOGUS END JOINING is not realll
> homologous directed reapir is real
mitochondira not capable of A binary fission B restriction (cutting) C transcription D translation E dna replication
OPTION B
chlorplast and mitchodria both replicatbe by binary fission!
which bacteria genus is not naturally competent to take up extracelluar DNA?
Escherichia - e.coli as we have to treat them woth chemicals
> competence: the ability of a cell to alter its genetics by taking up extracellular (“naked”) s..s DNA from its environment (transformation)
quite risky, only 2% pro can do this but can be made artifically competant
Competence allows for rapid adaptation and DNA repair of the cell.
Which of these methods of genetics transfer is mediated by prokaryotic viruses?
Transposition
Transformation
Conjugation
Transduction
Transduction occurs when some host cell DNA fragments are accidentally packaged by virus in a capsid after infection.
These capsules then go onto ‘infect’ other cells, but the DNA fragment can recombine with a homologous sequence
PROCESS OF ELIMINATION
What is an episomal plasmid?
Plasmid with sequences analogous to a host cell chromosome, not capable of reversible integration and excision
Plasmid with sequences analogous to a host cell chromosome, capable of reversible integration and excision
Plasmid with sequences homologous to a host cell chromosome, capable of irreversible integration and excision
Plasmid with sequences homologous to a host cell chromosome, capable of reversible integration and excision
Plasmid with sequences homologous to a host cell chromosome, capable of reversible integration only
OPTION D
episomal plasmid has sequences that are homologous to the host cell chromosome and is capable of both reversible integration and excision
> form of homologus recombination
how do the dna contentns of chromosome and alssmid differ?
chromosome has essential - rna ploymerase
plasmid has extra useful and junk genes - anitbiotic resistance
> not all prokary have plasmids!
what gene is needed in order to conjugate A rhab gene B tra gene C myoD gene D lac Y gene E pG01 plasmid
tra genes (transfer genes) that allow conjugation to occur by forming a pillus! > only 1/4 of plasmids have this ability!
what do sequence do transposase enzymes recognise?
the transpoable elements made up of short inverted repeats
> transposon betweeen DNA, conjugation between cells
what is a heteroplasmic mitcohondria/cell?
normal and mutant mitochondira genome present in the cell = impaired functin
> homoplamsic mutant and also therre is homoplasmic normal function
true or false?
prokaryotes only do horizonatal gene transfer, eukaryotes only do vertical gene transmission
FALSE!- prokary can do both!
> binary fission = vertical / down a lineage
> conjugation, transdution, transmission = horizontal between lineages
how many genes does mitcohondrial genome have?
37! but it is small with only 16kbp!
> chloroplast genome is larger (150kbp)
What is a tnp gene?
A A gene containing a singular insertion sequence
B The gene that produces a transposable element
C A gene that codes for a transposon
D The gene within an insertion sequence that codes for transposase
E The gene that recognises transposable elements
OPTION D
An insertion sequence contains a single tnp gene encoding for TRANSPOSASE which recognise transposable elements/inverted repeats.
A - The tnp gene does not contain an insertion sequence. The IS contains the gene.
B - Transposable elements are made of inverted repeats and flank the insertion sequence.
C - A transposon is a mobile gene mafe by a pair of IS that sandwich the chunk of DNA
E - The gene codes for ENZYME which then recognises a transposable element.
