Unit 6 - Genetic Variation in Prokaryotes

what do prokaryotic cells lack

nuclei and membrane bound organelles

what organelles do prokaryotic cells have

ribosomes for protein synthesis

what may some prokaryotic cells have

flagella for movement and capsule around cell wall

do prokaryotic cells have various shapes and arrangements

yes

bacterial genetics

single, circular bacterial chromosome in nucleoid region, often contain one or multiple plasmids

in the genes of prokaryotic cells what are “bonus” genes independent of

bacterial chromosome

in bacterial genetics what is coded for

traits such as antibiotic resistance and fertility factors

what is bacteria not

even though bacteria are asexual they are not clones

how is variation introduced in bacteria

mutations (chromosome and or plasmid replication), transformation, transduction, conjugation, transposable elements/transposons

mutations

changes in DNA during replication, grow and divide fast so errors happen and get passed on quickly

example of mutation

drug resistant bacteria

transformation

alteration of a bacterial cell’s genotype and phenotype by the uptake of naked, foreign DNA from the surrounding environment

transduction

phages carry bacterial genes from 1 host cell to another

generalized transduction

random genes are transferred

specialized transduction

genes adjacent to prophage site in temperate phages

conjugation

the direct transfer of genetic material between cells, bacterial “sex”

transposons

transposable genetic elements, “jumping genes”, pieces of DNA that move around within the genome