Organismal DevelopmentPart 1

Prokaryotic Organisms and Protists

Sexual Reproduction

Asexual - Budding

Asexual – Binary Fission

Origin ofreplication

Cell wall

Plasmamembrane

Bacterialchromosome

E. coli cell

Two copiesof origin

Chromosome replication begins. Soon thereafter, one copy of the origin moves rapidly toward the other end of the cell.

Replication continues. One copy of the origin is now at each end of the cell.

Origin Origin

Replication finishes. The plasma membrane grows inward, and new cell wall is deposited.

Two daughtercells result.

Platyhelminthes - Regeneration

Asexual – Binary Fission

Origin ofreplication

Cell wall

Plasmamembrane

Bacterialchromosome

E. coli cell

Two copiesof origin

Chromosome replication begins. Soon thereafter, one copy of the origin moves rapidly toward the other end of the cell.

Replication continues. One copy of the origin is now at each end of the cell.

Origin Origin

Replication finishes. The plasma membrane grows inward, and new cell wall is deposited.

Two daughtercells result.

Transformation

Bacterial Transformation – a type of asexual bacterial reproduction where genetic material is passed from bacteria to bacteria. Bacterial plasmids are modified and then placed into a new bacteria. This modified bacterial plasmid gives the bacteria new and novel functions.

Bacterial Transduction

A+

Phage DNA

A+

Donorcell

B+

A+

B+

Crossingover

A+

A– B–

Recipientcell

A+ B–

Recombinant cell

Bacterial Transduction – a form of bacterial asexual reproduction that is carried out by a virus (bacteriophage).

Bacteriophages can carry full strands of fragments of DNA and will insert this DNA into the genome of bacteria. Eukaryotic viruses work in a similar fashion and also carry DNA.

Once inserted into the genome, this DNA will now be read as part of the original genome. The new bacterial genome will now have new and novel functions.

Conjugation in Bacteria

Bacterial Conjugation – this is another form of asexual reproduction in bacteria that allows for genetic variation. Two bacteria will become connected by a “sex pillus” and genetic material will be transmitted between the two. The new genetic material will become part of the original genome.

Sexual Reproduction

Cell Cycle with checkpoints(Is all going according to plan?)

G2 followed by Mitosis

Mitosis followed by cytokinesis