Transcript Organismal Development 1 PPT

Organismal Development
Part 1
Prokaryotic Organisms and Protists
Sexual Reproduction
Asexual - Budding
Cell wall
Origin of
replication
Asexual – Binary
Fission
E. coli cell
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.
Replication finishes.
The plasma membrane
grows inward, and
new cell wall is deposited.
Two daughter
cells result.
Two copies
of origin
Origin
Plasma
membrane
Bacterial
chromosome
Origin
Platyhelminthes - Regeneration
Cell wall
Origin of
replication
Asexual – Binary
Fission
E. coli cell
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.
Replication finishes.
The plasma membrane
grows inward, and
new cell wall is deposited.
Two daughter
cells result.
Two copies
of origin
Origin
Plasma
membrane
Bacterial
chromosome
Origin
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
Phage DNA
A+ B+
A+ B+
Donor
cell
A+
Crossing
over
A+
A– B–
Recipient
cell
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