Bacterial Reproductive Methods

Bacterial Reproductive Methods

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Bacterial Reproduction:

Can be asexual or sexual

Three Main Methods:1. Binary Fission (asexual)2. Conjugation (sexual)3. Spore Formation (hibernation)

41. Binary Fission(division by half): DNA replicatedBacteria cell splits into two identical bacterial cellsContains an exact copy of the original cell's DNAOther examples; amoeba undergoes binary fission as well.5

6binary fission animationMultiplying bacteria2. ConjugationDirect transfer of genetic material between two bacterial cells that are temporarily joined

DNA transfer is one-wayDonor: male (has a special segment of DNA called Fertility Factor, F-factor, F+)Receptor: female(does not have F-factor, F-)Male donor has sex pili to attach to the female recipientThe F-factor contains approximately 25 genes and codes for the production of sex piliA cytoplasmic bridge forms between the two bacteria, allowing for DNA to be transferred

SEX PILUSDONORRECIPIENT

F Plasmid

HFr Conjugation3. Spore formation(mini hibernation)A method of reproduction, in which the bacteria forms protective spores when the environment is unfavourable.

Essential to protect bacterial genes

Spores are refer to endospores

Endospores: small spores which develop asexually inside the bacterial cell that consists of the bacterium's DNA surrounded by a protective cell wall.Remind class what happens in an unfavourable condition; relate to evolution14Endospore Formation: The bacterium undergoes dehydrationProtective 3 layer coat formsThe cell wall breaks apart Endospore remains dormant until conditions are favourable (absorbs water to break open the spore and creates a new cell wall

Endospore: a portion of the cytoplasm and a copy of the bacterial chromosome undergoes dehydration and gets surrounded by a three layer covering.15

Endospore: a portion of the cytoplasm and a copy of the bacterial chromosome undergoes dehydration and gets surrounded by a three layer covering.16

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Bacterial Reproduction Videoendospore formation