Genetics Flashcards
How many base pairs does E.Coli have?
5x10^6
How many base pairs does human cell have?
3x10^9
How many proteins does E.Coli Gene encode?
2000
How many proteins does human cell gene encode?
100,000
Define conditional lethal mutation
It’s a mutation only lethal under restrictive conditions (but may function under permissible conditions)
What is a silent mutation?
Change of codon but still codes for the same amino acid
What is a missense mutation?
Change in codon that causes change in amino acid being made
What is a non-sense mutation?
Change in codon that produces a stop signal
What is a frame shift mutation?
One or more base are added or deleted leading to shift the reading frame = inactive protein
4 examples of naturally transformable bacteria?
1) streptococcus pneumonia
2) haemophilus influenzae
3) Neisseria gonorrhoea
4) vibrio cholera
Define transformation?
Taking naked DNA
(usually dead bacteria)
Define transduction?
Gene transported by bacteriophage from one bacteria to another
Give 4 example on lysogenic conversion?
Corynebacterium diphtheria
Vibrio cholera
Clostridium botulinum
Streptococcus pyogenes
Define conjugation?
Plasmids move by cell-cell contact
Define the two types of competence in transformation
Natural competence
&
Artificial competence
(by electroporation)
What are the states of a bacteriophage?
Lytic & temperate (lysogen)
What are the phage & bacteria called during lysogeny?
The phage: Prophage
The bacteria: lysogen
Define lysogenic conversion
Change of lysogen phenotype after the phage encodes an observable function
What is the toxin produced from streptococcus pyogenes & what is the disease?
Erythrogenic toxin which causes scarlet fever
Generalized vs specialized transduction ?
Generalized: All of the capsid is filled with random bacterial genome
Specialized: a specific part of bacterial genome is mixed with the virus’ own genome in the capsid
How is the genome for virulence exchanged ?
By generalized transduction
How is the genome for antibiotic resistance exchanged ?
Generalized transduction
Or Transposons
How is the genome for multiple antibiotic resistance exchanged ?
Conjugation
