Ch.8 Microbial Genetics Flashcards
Genetics: the study of —, how they carry —, how information is —, and how genes are —
- genes
- Information
- Expressed
- Replicated
Chromosomes: structures containing — that physically carry — information; the — contain —
- DNA
- Hereditary Information
- Chromosomes contain genes
Genes: Segments of — that encode ——, usually —
- DNA
- Functional products
- Proteins
Genome: all the —— in a —
- Genetic Information
- Cell
Genotype:
~ The — makeup of an organism
~ The information that — for all the particular — of the organism
~ ——
- Genetic
- Codes, Characteristics
- Potential Properties
Phenotype: — of the genes
~ —, — properties
~ the — of genotype
- Expression
- Actual, Expressed
- Manifestation
Regulation of Bacterial Gene Expression:
~ — genes are expressed at a — rate
~ Other genes are expressed as needed
* — genes
* — genes
* — repression
- Constitutive, Fixed
- Inductively
- Repressive
- Catabolite
Pre-transcriptional Control:
~ Repression inhibits —— and decreases ——
* Mediated by —, proteins that block transcription
* Default position of a repressive gene is —
- Gene Expression, Enzyme Sythesis
- Repressors
- On
Pre-Transcription Control:
~ Induction turns — gene expression
* Initiated by an —
* Default position for a inducible gene is —
- On
- Inducer
- Off
Operon Model of Gene Expression:
~ Promoter: segment of DNA where —— intiates — of structural genes
- RNA polymerase
- Transcription
Operon Model of Gene Expression:
~ Operator: segment of DNA that —— of structural genes
Controls transcription
Operon Model of Gene Expression:
~ Operon: set of — and — sites and the structural genes they —
- Operator & Promoter
- Control
Operon Model of Gene Expression:
~ In an inducible operon, structural genes are not — unless an — is present
* In the absence of lactose, the — binds to the —, preventing —
* In the presence of lactose, lactose (inducer) binds to the —; the repressor cannot bind to the — and — occurs
- Transcribed, Inducer
- Repressor, Operator, Transcription
- Repressor, Operator, Transcription
Operon Model of Gene Expression:
~ In repressible operons, structural genes are — until they are turned —
* Excess — is a — that binds and activated the repressor to bind to the operator, stopping — synthesis
- Transcribed, Off
- Tryptophan, Corepressor, Tryptophan
Positive Regulation:
~ Catabolite repression: inhibits cells from using — sources other than —
- carbon
- Glucose
Positive Regualtion:
~ Cyclic AMP (cAMP) builds up in a cell when — is not available
~ cAMP binds to the ——, initiating — and allowing the cell to use —
- Glucose
- Lac promoter, Transcription, Lactose
Changes in Genetic Material:
~ Mutation: a — change in the —— of DNA
~ Mutations may be —, —, or —
- Permanent
- Base Sequence
- Neutral, Beneficial, or Harmful
Mutagens: agents that ——
Cause mutations
Spontaneous Mutations: occur in the absence of a —
Mutagen
Types of Mutations:
~ ——: change in one base in DNA
Base Substitution (point mutation)
Types of Mutations:
~ ——: Base substitution results in change in an amino acid
Missense Mutation
Types of Mutations:
~ ——: Base substitution results in a nonsense (stop) codon
Nonsense Mutation
Types of Mutations:
~ Frameshift mutation: — or — of one or more — pairs. Shifts the translation “——“
- Insertion or Deletion
- Nucleotide
- Reading Frame
Chemical Mutagens:
~ Nitrous Acid: causes — to bind with — instead of —
- Adenine
- Cytosine
- Thymine
Chemical Mutagens:
~ Nucleoside Analog: incorporates into — in place of a ——; causes mistakes in ——
- DNA
- Normal Base
- Base Pairing
Radiation:
~ Ionizing radiation (X-rays and Gamma Rays) causes the formation of ions that can oxidize — and break the ——— backbone
- Nucleotides
- Deoxyribose-phosphate
Radiation:
~ UV radiation cause ——
Thymine dimers
Radiation:
~ — separate thymine dimers back to the original ——
- Photolyases
- Two Thymines
Radiation:
~ Nucleotide excision repair: — cut out incorrect — and fill in correct — from other causes as well
- Enzymes
- Bases
- Bases
The Frequency of Mutation:
~ Spontaneous mutation rate = 1 in 10^ — replicated base pairs or 1 in 10^ — replicated genes
~ Mutagens increase the mutation rate to per 10 ^ — or 10^ — replicated gene
- 9
- 6
- -5, -3
Genetic Transfer and Recombination:
~ Genetic Recombination: exchange of — between —— molecules; creates — diversity
- Genes
- Two DNA
- Gentic
Genetic Transfer and Recombination:
~ Crossing Over: —— break and rejoin, resulting in the insertion of —— into the —
- Two Chromosomes
- Foreign DNA
- Chromosome
Genetic Transfer and Recombination:
~ Vertical Gene Transfer: transfer of genes from an — to its —
- Organism
- Offspring
Genetic Transfer and Recombination:
~ Horizontal gene transfer: transfer of genes between — of the ——
- Cells
- Same Generation
Genetic Exchange in Bacteria:
~ Recombinant: any organisms that contained — that — in another organism
- Genes
- Originated
Genetic Exchange in Bacteria:
~ DNA transfer between bacterial cells typically involves small pieces of DNA in the form of — or ——
- Plasmids
- Chromosomal Fragments
Plasmids:
~ Plasmids are ——— pieces of —
~ 1 to 5% the size of a — chromosome
~ Often code for — that enhance the — of a —
- Self-replicating circular, DNA
- Bacterial
- Proteins, Pathogenicity, Bacterium
Genetic Exchange in Bacteria:
~ One bacterium donates — to another — is a type of genetic transfer termed —
- DNA (donor)
- Bacterium (recipient)
- Recombination
Genetic Exchange in Bacteria:
~ —— gives a portion of its total DNA
Donor Cells
Genetic Exchange in Bacteria:
~ —(——) receive the DNA from donor cell
Recipient (competent cells)
——— in bacteria involves a portion of the cell’s DNA being transferred from donor to recipient
Horizontal Gene Transfer
——— occurs during reproduction when genes are passed from an organism to its offspring
Vertical Gene Transfer
Conjugative Plasmid: carries genes for —— and — of the plasmid
- Sex pili
- Transfer
Dissimilation Plasmids: encode — for the — of — compounds
- Enzymes
- Catabolism
- Unusual
Plasmids:
~ Resistance factors (R factors): encode ——
Antibiotic resistance
Conjugation in Bacteria:
~ Conjugation: — transferred from one — to another
~ Requires — to — contact via ——
- Plasmids, Bacterium
- Cell-to-Cell, Sex pili
Conjugation in Bacteria:
~ Donor cells carry the —(——) and are called — cells
~ — cells contain the — factor on the chromosome
- Plasmid (F factor), F+
- HFR, F
Transformation in Bacteria:
~Transformation: genes transferred from one — to another as “ —“ —
- Bacterium
- “Naked” DNa
Transduction in Bacteria:
~ DNA is transferred from a donor cell to a recipient via a —
Bacteriophage
Transduction in Bacteria:
~ Generalized transduction: — bacterial DNA is packaged inside a — and transferred to a — cell
- Random
- Phage
- Recipient
Transduction in Bacteria:
~ Specialized Transduction: — bacterial genes are packaged inside a — and transferred to a — cell
- Specific
- Phage
- Recipient
Transposons
~ Transposons are segment of DNA that can — from one — of — to another
~ ——— that code for transposable that cuts and reseal DNA
~ —Transposons carry other genes (e.g. antibiotic resistance)
- Move, Region, DNA
- Contain Insertion Sequences (IS)
- Complex
Genes and Evolution:
~ Mutations and recombination create ——
~ Diversity is the —— for —
~ Natural selection acts on — of organisms to ensure the — of organisms fit for a particular environment
- Cell Diversity
- Raw Material, Evolution
- Populations, Survival
