Term
| Two definitions of genetics |
|
Definition
Study of heredity Study of genes through their variation |
|
|
Term
|
Definition
The physical and functional unit of heredity Segment of DNA on a specific site of a chromosome |
|
|
Term
|
Definition
| Complete DNA sequence of an organism containing its genetic information |
|
|
Term
| structure of a chromosomal DNA |
|
Definition
circular, double-stranded molecule |
|
|
Term
| Definition of DNA (functional) |
|
Definition
| self-replicating genetic element |
|
|
Term
|
Definition
| in a nucleoid, attached to the plasma membrane |
|
|
Term
|
Definition
| small, circular, ds-DNA molecules |
|
|
Term
| Definition of plasmids (functional) |
|
Definition
| extrachromosomal genetic elements that exist and replicate independently of the bacterial chromosome |
|
|
Term
| How many genes does a plasmid have? |
|
Definition
|
|
Term
| What do plasmids code for? |
|
Definition
| Traits that are not essential for normal metabolism, growth, or cellular respiration |
|
|
Term
| Fertility factors (F) - genes that they carry are responsible for what? |
|
Definition
| cell attachment and plasmid transfer between bacterial strains during conjugation |
|
|
Term
|
Definition
| direct the formation of a sex pili that attach the F+ cell to an F- cell |
|
|
Term
| Resistance factors (R) - the genes that R factors carry code for what? |
|
Definition
| code for enzymes that can destroy or modify antibiotics or heavy metals |
|
|
Term
| What can R factors confer? |
|
Definition
|
|
Term
|
Definition
| bacterial proteins that destroy other bacteria |
|
|
Term
|
Definition
| kill bacterial cells of the same or similar species that lack the factor |
|
|
Term
| Why are Col plasmids advantageous to a bacterium? |
|
Definition
| a bacterium containing the plasmid can kill its competitors |
|
|
Term
|
Definition
| carry instructions for structures, enzymes, or toxins that enable the bacterium to become pathogenic |
|
|
Term
| What are virulence plasmids advantageous to the bacterium? |
|
Definition
| better able to resist host defenses |
|
|
Term
| What do genes of Metabolic plasmids do? |
|
Definition
Carry genes for enzymes that degrade substances such as aromatic compounds, pesticides, and sugars (e.g. bumps/nodules on roots of legumes) |
|
|
Term
| define transposable elements |
|
Definition
| DNA segments that carry the genes that are required for transposition |
|
|
Term
|
Definition
| movement from one location in a DNA chromosome to another location in the same or a different chromosome |
|
|
Term
| What kind of genes do transposable elements carry? |
|
Definition
| antibiotic resistance genes that can be transposed to other plasmids or to the bacterial chromosome |
|
|
Term
| Define genetic recombination |
|
Definition
| Exchange between 2 DNA molecules of segments that are composed of identical or nearly identical nucleotide sequences (homologous sequences) |
|
|
Term
| What does genetic recombination result in? |
|
Definition
| recombinant (recombined from 2 sources of DNA) DNA molecule |
|
|
Term
| 2 steps of genetic recombination |
|
Definition
- transfer of DNA from one cell to another
- transferred donor DNA may be integrated into the recipient's chromosome
|
|
|
Term
| 3 steps in horizontal gene transfer |
|
Definition
- transformation
- conjugation
- transduction
|
|
|
Term
|
Definition
| DNA fragments released from dead donor bacteria are taken up directly from the extracellular environment by living recipient bacteria; then the donor DNA recombines w/the bacterial chromosome |
|
|
Term
|
Definition
| the ability of bacteria to take up extracellular DNA and to become transformed |
|
|
Term
|
Definition
| transfer of DNA from a living donor bacterium to a recipient bacterium and is mediated by a sex pili |
|
|
Term
| 4 Steps in F+ conjugation |
|
Definition
- F pili bind to outer membrane protein on recipient bacteria to initiate mating.
- direct contact creates a cytoplasmic bridge
- copy of the F+ plasmid is transferred from a donor to the recipient bacterium
- The recipient becomes F+ and can make a sex pili
|
|
|
Term
| High frequency recombinant (Hfr) cell |
|
Definition
| a cell in which an F plasmid has integrated itself into the bacterial chromosome |
|
|
Term
| 3 Steps of Hfr conjugation |
|
Definition
- Transfer of a part of chromosomal DNA from an Hfr donor to a recipient
- Connection breaks before transfer of the entire chromosome is completed
- There is a transfer of some chromosomal DNA but not F plasmid, so the recipient cell is still F-; however the cell is recombinant
|
|
|
Term
Differences in how two bacteria come into contact b/w Gram - and Gram + bacteria |
|
Definition
Gram -: sex pilus Gram + : surface molecules |
|
|
Term
|
Definition
| transfer of fragments of DNA from one bacterium to another by a bacteriophage |
|
|
Term
| What is a bacteriophage's role in transduction? |
|
Definition
| a bacteriophage functions as a vector to introduce DNA from donor bacteria into recipient bacteria by infection |
|
|
