Module 5 - Bacterial Genetic Analysis and Manipulation Flashcards
Which scientist wondered whether sexual crossing/genetic exchange occurred in bacteria?
Joshua Lederberg
What type of mutants can ONLY grow if the growth medium contains the appropriate amino acids or vitamins?
Nutritional mutants
How to describe this condition: met- strain needs methionine but NOT proline to grow in the medium
met- pro+
How to describe this condition: pro- strain requires proline but NOT methionine to grow in the medium
pro- met+
What kind of chromosomes do bacterial cells exhibit (GENERALLY)
Single, circular
What structures are known as smaller, circular DNA molecules that replicate independently of the chromosome?
Plasmids
What are accessory functions that plasmids contain genes for?
- Antibiotic resistance
- Degradation of toxic substances
What is the term used to describe the hereditary material of a bacterial cell, including BOTH the chromosome(s) and any existing plasmids?
Genome
What is bacteria Streptomyces responsible for? What kind of chromosome does it exhibit?
- Producing soil bacteria
- Linear chromosome
What is bacteria Borrelia burgdorfer responsible for? What kind of chromosome does it exhibit?
- Causative agent of human Lyme’s disease
- Linear chromosome
What is bacteria Agrobacterium tumefaciens responsible for? What kind of chromosome does it exhibit?
- Plant tumor
- Circular chromosome, linear chromosome, and 2 large circular plasmids
What is the term use to classify each chromosome and plasmid?
Replicon
In cells containing plasmids, each cell has a controlled number of plasmid numbers known as the …?
Copy number
What makes plasmids incompatible?
When they cannot exist stably within a population of cells
What happens during plasmid incompatibility?
Cell loses count of how many copies of each of the two plasmids exist within the cell
What is the term used to describe the typical or representative characteristics of a species?
Wild-type strain
What is Sinorhizobium meliloti?
- Nitrogen-fixing bacteria
- Most commonly studied wild-type strain
A cell or strain possessing a mutation, or a change in its DNA sequence relative to the comparable sequence in the wild-type strain is called?
A mutant
What is another term for “form of the gene”?
Allele
What is the term that describes a loss in gene function, regaining of function of previously mutated gene, or modification of gene function (results in phenotypic change)
Mutation
What are two other ways that mutations arise besides spontaneously?
- UV light
- DNA-damaging chemicals
How are genes named?
Three-letter, lowercase, italicized
What is the term that describes the alleles within an organism?
Genotype
What method of detecting mutants involves plating bacteria on a selective growth medium that only allows strains with a particular combination of phenotypic characteristics to grow and form a colony?
Phenotypic Selection
What method of detecting mutants does not prevent the growth of cells with a wild-type phenotype rather all cells form colonies under the tested conditions?
- Usually necessary for recovering mutants for which there are no identified conditions under which they can grow
Screening
What method of detecting mutants are colonies lifted from one plate using a piece of sterile velvet cloth and then deposited onto a fresh plate?
Replica plating
What question did Esther Lederberg’s experiment prove?
Can fitness increase through mutation without a direct selection for that that?
How did Salvador Luria and Max Delbruck further investigate whether mutations originate randomly and spontaneously?
Investigated the generation of resistance in E. coli to infection with the bacteriophase T1
What is the term given to bacterial proteins that cleave DNA at specific sequences?
Restriction enzymes
Short DNA sequence, usually of 4, 6, or 8 base pairs are also known as?
Restriction site
What does the restriction site recognize?
Palindromic site
What is term to describe reverse and put together
Ligate
What makes the separate pieces of DNA easy to ligate?
Sticky ends
What is the term to describe a cut somewhere in the middle of a chain
Endonuclease
What results after ligation and annealing?
2 new recombinant DNA
