Microbial Genetics Part 2 Flashcards by Brina Quintanilla Reyes

What are the 4 ways that bacteria get genetic variation ?

Mutations
Transduction
Transformation
Conjugation

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What does genetic transfer mean?

Movement of genetic information between organisms

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When does genetic transfer occur in eukaryotes?

During fertilization of an egg

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When does genetic transfer occur in prokaryotes ? However when it does happened??

It doesn’t happened
It isn’t needed

dna is transferred from a donor to a recipient cell

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What does genetic recombination mean?

Combining genes (DNA) from two different dna molecules

( donor cell and recipient cell pretty much )

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What is the donor cell doing in genetic transfer ?

Giving up dna

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What is the recipient cell doing in genetic transfer?

Receives the DNA

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When new DNA combines with the host DNA ( already, personal dna ), what is it called?

Genetic recombination

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What’s the 4 steps of genetic recombination?

DNA from one cells sees that they can pair
DNA donor joins together with DNA recipient
they join by recA protein catalyzes
recipient has its own dna and donor dna now

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What are the 3 methods genetic transfer in bacteria?

transformation
transduction
conjugation

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What’s the end result for all of the 3 methods of dna transfer ?

Gaining a new gene

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What does transformation mean ?

Getting a new gene by naked dna ( free floating dna )

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What does naked dna mean in transformation, genetic transfer ?

Free floating dna in the environment

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What is Frederick Griffith known for and what year did he discover it?

Transformation, 1928

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What was Frederick Griffith experiment on? And what disease ?

On rats
Using streptococcus pneumonia

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What are the 3 steps to genetic transformation?

recipient cell takes donor dna
donor dna aligns with complementary bases
recombination occurs between donor dna and recipient dna

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What is the end result and gain what for transformation ( genetic transfer )?

Gaining a new gene
Through the use of naked dna
( free floating dna in the environment )

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What is conjugation ?

The direct cell to cell contact through a plasmid that makes a new gene

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What is the F plasmid ( f factor )? And causes what to occur?

Fertility sex pilus, what causes conjugation to occur

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What’s another name for f plasmid ?

Donor, male, F+ and F factor

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What’s another name for F- cell?

Recipient, female, f-

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What’s another name for sex pilus?

Conjugation pilus

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What does the sex pilus allow?

The direct cell to cell contact

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What is a plasmid?

Small extra chromosomal double stranded DNA

What does HFr stand for?

High frequency recombination cell

HFr doesn’t have ___ instead they contain the ___ of ___

HFr doesn’t have plasmids Instead they contain the genes Of The plasmids

HFr is the transfer of what?

Plasmid genes and chromosomal dna

What are the 4 steps of normal conjugation?

- F+ cell extend sex pilus to F- cell - the cells come together to transfer ( through fusion of cell membranes ) - a single stranded copy of the F+ cell is transferred to the F- cell - both cells now have the gene F+

When normal conjugation is done, can the new F+ give to another cell, even after being a F- and now F+?

Yes, cause it was F- turned into F+

What happened when the F factor integrates in the host chromosome dna ?

It makes HFr

What is the 4 steps of HFr transfer in conjugation ?

- f factor is integrated into host DNA - converts f factor into HFr - HFr crosses over to F-Cell However we only get a portion of gene plasmids mix in with chromosomes - F- cell Stays F-, even after HFr Because it didn’t fully get plasmid Only contains portion of the genes of plasmids

In normal F plasmid conjugation, is F+ found in the cytoplasm or chromosome ?

Cytoplasm

In HFr conjugation, is it found in cytoplasm or in Chromosome ? And why?

Chromosome Because it’s integrated

Can HFr still perform conjugation?

Yes

What’s the big difference in F plasmid and HFr ?

F plasmid - only transfer plasmids HFr - gene plasmid and chromosome

Does HFr have a plasmid?

What does HFr contain?

Gene plasmid and chromosome

What is transduction ?

Transfer of genetic material by virus

What does bacteriophage mean?

A virus that infects a bacteria

What are bacteriophages?

Obligate intracellular parasites

What does transduction undergo? ( 2 types of methods ) ( not 2 types of transduction )

Lytic bacteriophage Temperate of lysogenic phage

What are the steps of lyric bacteriophage? (4)

- virus injects dna in bacteria - dna synthesis occurs, producing virus babies ( progeny ) - cell lysis, and release progeny - repeats

What does progeny mean?

The offspring of a virus that is released

Can lytic cycle enter the temperate lysogenic phage cycle?

Can lysogenic ( temperate ) cycle enter the lytic cycle?

Yes

What is the steps of temperate of lysogenic phage cycle? (4)

- bacteriophage inserts into the bacteria chromosome ( this is called prophage ) - Binary fission occurs - every time it divides it has that prophage - Eventually it’ll be ready to make virus babies, so it’ll cut itself out and move into the lytic cycle

What is a prophage?

Bacteriophage that inserts into a bacteria’s chromosome

What are the 2 types of transduction ?

Generalized transduction Specialized transduction

What are the steps to generalized transduction? (5)

- injects DNA virus into DONOR cell - makes copies ; breaking down the dna chromosome - these piece are either virus or DNA Chromosome & PICKS UP RANDOM PIECE ( the chromosome ) - bacteria dna infects a new host with the new dna - recombination occurs ( dna from donor & recipient dna together ) Gains new gene

Is generzalized transduction random selecting?

Yes

What are the steps for specialized transduction? (6)

- prophage integrates with bacterial DNA - prophage take out specific Chromosome - prophage matures & cell lyses - bacteriophage infects another bacteria, instead now it has virus & piece of chromosomes - integrates into bacteria DNA - recipient now has virus, gene, and its own dna integrated into the Chromosome

Is specialized transduction specific chromosome selection?

Yes

Big difference in generalized transduction and specialized transduction?

Generalized - random choosing of dna or virus Specialized - prophage, virus goes into chromosome - specific choosing of Chromosome

What is an r factor?

Codes for resistance to antibiotics, very important medically

What are the 2 groups of genes in r Factor?

RTF r determinant

What does RTF mean?

Resistance transfer factor

What does r Determinant mean?

Genes for detoxifying enzymes Usually carried on transposons

What is a transposable gene?

Small segments of dna which can move from one region of dna to another region