Bacterial Genetics

Single circular, cytoplasm

Bacterial Chromosome

• __ __ chromosomes = dsDNA

• Found in at the __ “nucleoid” region and genome of 600-6000 genes

Bacterial Plasmids

Extra chromosomal elements

Small circular, not, multiple

Bacterial Plasmids

• __ __ dsDNA

• Only few genes in plasmids

• Genetic information __ (is/not) essential to survival of cell

• One bacterial cell can have __ copies of a plasmid

DNA, single genes, operons

Eubacteria Gene Expression

• Bacterial genes present on __ (DNA/RNA) act as:

  • (1) __ __: Separate discrete units

  • (2) __: Multigene complexes transcribed from single promoters

Nuclear membrane, mRNA, coupled

Absence of a __ __ in bacterial cells allows simultaneous transcription and translation

• No introns or exons in eubacteria means NO __ processing

• Transcription and translation __ to cytoplasm of bacterial cells

70s, antibiotic

Bacterial ribosomes have the __ ribosome

• Target for many__ drugs

Binary Fission

Asexual reproduction of bacteria by cellular division

Rapidly, no spindles, identical

Bacterial cell reproduction

• Can take place __ (pace) and __ __ involved, such as in mitosis

• End product of 2 genetically __ daughter cells

One, before, 5’3’

Replication of bacterial main chromosome

• __ origin(s) of replication

• Replication occurs only __ (before/after) binary fission

• Direction of bacterial DNA synthesis is _’ → _’

Independently, many

Replication of plasmids

• Plasmids replicate __ of bacterial chromosome

• Bacterial cell may contain __ copies of a plasmid

Antibiotic, toxins, virulence, integrated, plasmid

Horizontal gene transfer

• Allows exchange of characteristics including: __ resistance, various __, __ factors

• Transferred DNA can be __ into host cell chromosome or maintained as extrachromosomal element (__)

• 3 methods - transformation, transduction, conjugation

Transformation

Uptake of DNA from environment by competent cells

Recombination, degradation, lysis, manipulation, cloning

Transformation

• Integration by__ (acceptance of external DNA to chromosome) OR __ (rejection of external DNA to chromosome)

• Recipient cell can take up external DNA released from another cell’s __

• Process frequently used in lab for genetic __ and gene __

Transduction

Transfer of genes from one bacterial cell to another via bacteriophage

Bacteriophage, cytoplasm, capsid

Transduction

• __ bind to surface of bacterial cell and “inject” genetic material into cell __

• protein __ remains intact of bacteriophage

Lytic Cycle

Bacterial cell bursts open to release new progeny bacteria after injection/infection

(Transduction outcome)

Lysogenic Cycle

Bacterial cell has bacteriophage DNA integrated into bacterial DNA but survives

(Transduction outcome)

Lytic, death

Bacteria in the lysogenic cycle can eventually re-enter the __ cycle and lead to bacterial cell __

(Transduction outcome)

Temperate bacteriophage

Bacteriophage that establish lysogeny in first bacteria with insertion of phage genome to second bacteria

Prophage

Name for bacteriophage DNA when inserted into host bacterial chromosome

Conjugation

Transfer of genetic information from donor to recipient cell via touch

F Plasmid

Specific genes on plasmid that are required for conjugation

R plasmid, non-pathogenic

_ __ is an F Plasmid variant that contains genes for antibiotic resistance

• __-__ bacteria can be a source of these plasmids

close, sex, bridges, species

Conjugation

• Requires __ contact of 2 bacterial cells via __ pili or __

• Conjugation can be seen in specific types of both gram (+) and (-) bacteria

  • May cross __ lines