Chapter 16 Flashcards
The corrections of error in base pairing made during DNA replication is done by ?
DNA polymerase
Mismatched pairs are removed and replaced by DNA polymerase ? T or F
True
What is the purpose of excision repair?
To correct damage that distorts the DNA double helix
The two types of excision repair
Nucleotide and base excision repair
What is the differance in Nucleotide excision repair and base excison repair?
Nucleotide removes and repairs the entire nucleotide
base excision removes and repairs only the incorrect base
The purpose of recombinational repair?
Corrects the DNA that has both bases of a pair missing or damaged
Rec A aligns the damaged DNA with the second copy of the genome. T or F
True
The SOS response purpose is ?
It is an inducible repair system, used when damage is too far for normal mechanisms
In the absence of DNA damage what occurs to the SOS gene
LexA binds to SOS gene promoter, inhibiting expression
What occurs during SOS repsonse when DNA is damaged ?
RecA protiens are expressed and they localize the damaged ss DNA strands
Rec A serves as a locator for LexA, which allows for it to bind. It activates the degradation of Lex A, thus inhibting SOS genes. T or F
False
It allows for SOS genes to be expressed for transcritption
def of vertical gene transfer
transfer of genes from parents to progeny
horizontal gene transfer
genes from one independent mature organism to another
In horizontal gene transfer genes can only be transferred to the same species, not different species. T or F
false
they can do both
Conjugation def.
DNA transferred from a donor
DNA that is acquired directly from enviroment is called conjugation. T or F
False
transformation
DNA that is transported in a bacteriophage
transduction
Integration
Donor DNA Pairs with recipients DNA and recombines
What is the DNA fate in the recipient
Integration-pairs
Separate existence of DNA- stays seperate
Degradation-Crispr
How are genetic elements able to move within and between genomes?
Via transposition
What are other ways to call the elements that are able to move within and between genomes?
Transposable elements or transposons
Composite transposon
contain gene unrelated to transposition
In simple transposition what enzyme catalyzes the excision of the mobile genetic element
Transposase
what occurs in replicative transposition?
mobile geneic element remains at original site in DNA
Copy is inserted to the new DNA site
Small double stranded DNA molecules
Conjugative plasmids
What type of plasmid can have their own replication orgins and replicate autonomously and stability inherited
Conjugative plasmid
The F factor is how many base pairs long?
100,000 bp
Bears genes responsible for cell attachment and plasmid transfer between E.coli cells
F factor
The F factor contains 30 plasmid transfer genes in the tra operon
False they contain 28
Episome that can exist outside chromosome or be integrated? T o F
true
extrachromosomal f factor carrying genes for sex pilus formation and plasmid transfer
F+ strain
Hfr Conjugation
Donor transfers chromosomal genes but does not change recipients into f+cells
Immunity genes
resistance genes that exist in nature to protect antibiotic producing microbes from their own antibiotics
where can resistance genes can be found
bacterial chromosomes
plasmids
transposons
other mobile genetic elements
can be transferred to other cells by HGT, their genes code fro enzymes that destroy or modify drugs
resistant plasmids
