Genetics and Genomics Flashcards
What are various technologies that effect your life?
- GMOs
- Biologicals and drug production
- Enzyme production
- Treatment of disease
What is a genome?
The complete genetic content of a cell or organism
What makes up the genome in Bacteria and Archaea?
-Chromosome(s)
-Plasmids
What makes up the genome in Eukarya?
-Chromosome(s)
-Plasmids
-Organelle Chromosomes
Chromosomes are considered to be _____ while plasmids are considered to be _____.
essential, non-essential
What is the shape of a chromosome and how big is it?
Circular and normally 1-12Mb
TRUE or FALSE? In the environment there are many different ways to arrange chromosomes and it varies form organism to organism.
TRUE
Bacterial and Archaeal genomes contain mostly _____. (___%)
Coding sequence 88%
Eukaryotic genomes are full of _____.
Non coding sequence
What are plasmids?
Circular dsDNA in microbes that can direct their own replication but they use host machinery
Plasmids encode for what?
Accessory functions that are not necessary for survival (antibiotic resistance and pigment production)
How do plasmids replicate?
Use host cell replication machinery and have plasmid encoded proteins that co-opt the cell’s replication proteins.
What is essential for plasmid replication?
Ori (origin of replication)
Plasmids are generally described as ______ DNA.
Selfish
How does plasmid segregation work for both a low copy number of plasmids and a high copy number of plasmids?
Low copy replication is coordinated with chromosome replication
High copy number of plasmids, random partitioning occurs.
What is the purpose of the toxin-antitoxin systems?
Preventing the activity of a toxin
Are toxins or antitoxins more stable?
Toxins
What happens to the plasmid if the antitoxin is lost?
Degraded
What are example targets for toxin-antitoxin systems?
- DNA gyrase
- mRNA
- Translation
- Peptidoglycan synthesis
What are the different ways a genome can change?
- Errors during DNA replication
- Spontaneous chemical changes
- DNA damage
When there is a genetic error what cell is affected?
Daughter cell
What is photoreactivation?
When a protein uses light to reverse a mutation in the gene
What is base excision repair?
Replacing one wrong nucleotide using DNA glycolase, AP endonuclease, DNA polymerase
What is methyl mismatch repair? How does it work?
Using methyl groups to mark errors for repair
- MutS recognizes mismatch
- MutH binds to nearest methylated GATC
- Non parent strand degraded
- DNA poly II fills gap
What is Recombination repair?
Used when there is 3-4 bp mess up and uses DNA recombination similar sequence to fix errors
What is SOS repair? When should you use SOS repair?
USE WHEN NOTHING ELSE WORKS
- DNA polymerase stops
- RecA binds
- SSB and PolV complex appears
- Error prone repair
- Polymerase begins again
What is horizontal gene transfer?
lateral gene transfer
What is conjugation?
- DNA moves between two living things
What is transduction?
- DNA is moved by virus
What is transformation?
- Ability to take up free DNA
Do self replicating DNA (plasmids) need to be maintain?
NO thee y self replicat
How does linear DNA integrate into the genome?
- Recombination of the genome
- Homologous recombination repair mech
Who studied transformation with treptococcus pneumoniae in mice?
Fred Griffith
Cells that are capable of transformation are generally called what?
“Competent”
What is artifical competence?
When transformation of the genes is carried out in the lab (heat shocks/ electroshocks)
What is the conjugation?
Movement of a plasmid from one live cell to another
How do plasmids conjugate?
They encode for conjugation machinery and can move DNA between bacteria that are not closely related
What are integrated plasmids capable of doing?
Facilitating genome movement
What is the F factor? How does it work?
Conjugable plasmid
- 1-2 copies per cell
- tra region encodes transfer
-oriT is start of site for transfer
- oriV is for replication
- contains toxin-antitoxin system
-takes 5 minutes to transfer
What is the difference between the Core genome and the pan genome?
- Core genome is common to all members of the species
- pan genome is found in some but not all members
