pt 1. genome and genomics final review

transformation, transduction, conjugation

what are the 3 ways prokaryotes exchange genetic info?

the uptake of free DNA fragments from dead and lysed cells

what is transformation

transformation

Strep. gains antibiotic resistance by which genetic exchange method?

the transfer of DNA between bacteria, via a bacteriophage

^it transfers the first bacteria's DNA to the second bacteria it infects

what is transduction?

direct transfer of DNA through a pilus

what is conjugation?

1) donor cell with an F plasmid (fertility factor)

forms a pilus that connects to

2) a recipient cell

what are the two subjects of conjugation?

E. Coli shares plasmids carrying antibiotic resistance this way

what is an example of conjugation

a bacterial strain that can make all the amino acids and other molecules it needs from basic nutrients

- E coli only needs glucose, sale, and a nitrogen source

What is a prototroph?

a mutant that cannot synthesize all of the compounds it needs

what is an auxotroph?

an auxotroph that cannot produce leucine by itself. it must be grown on a medium that contains leucine.

leu- mutant of E. coli is an example of what?

okay

please review gene mapping for bacteria

Nonessential "accessory" chromosomes, such as plasmids or modified bacterial viruses.

what is a vector?

A sample of DNA molecules containing of gene of interest

what is donor DNA?

DNA molecules formed by fusion of donor DNA fragment and vectors (do not exist naturally)

what is recombinant DNA?

processes used to create copies of recombinant DNA.

what is DNA cloning?

mutations and recombination

what are the two major processes responsible for genetic variation?

heritable change in the genetic information encoded by the DNA

how are mutations defined?

it causes alleles of different genes to become grouped in different combinations

what does recombination do?

spontaneous and induced

what are the two main types of mutations?

- Mismatched base pairs

- Errors in DNA Replication by DNA polymerase

what are two sources of spontaneous mutations?

agents that enter the cell and cause sequence changes

what is a mutagen?

an altered codon ends up coding for the same amino acid

what is a synonymous mutation?

altered codon codes for a chemically similar amino acid

what is a conservative missense mutation?

altered codon codes for a chemically DISsimilar amino acid

what is a nonconservative missense mutation?

altered codon signals for termination/stop

what is a nonsense mutation?

frameshift

a base insertion or deletion causes what type of mutation?

changes in DNA that happen because of exposure to mutagens — things like chemicals, radiation, or certain biological agents

what are induced mutations?

when scientists intentionally cause induced mutations

what is mutagenesis?

- replace a base in the DNA

- alter a base in the DNA

- damage a base in the DNA

what are the three ways mutagens can affect DNA?

- spontaneous is caused by the cellular environment

- induced is caused by exogenous chemical agents

what is the difference between spontaneous mutations and induced muatation?

alkylation, oxidation, deamination, depuration

what are the four types of base excision repairs?

pyrimidine dimer, and bulky adduct

what are the two types of nucleotide excision repairs?

alkylation and pyrimidine dimer

what are the two direct repairs?

nonhomologous end joining occurs in G1 phase

homologous recombination occurs in G2 or S phase

what is the difference between nonhomologous end joining and homologous recombination?

Ku70-Ku80 complex

in NHEJ, what binds to the broken DNA ends to prevent degredation?

DNA Ligase IV, XRCC4, XLF

what ultimately reattaches the DNA in NHEJ?