Plate 15 - Bacterial
Reproduction
Sexual vs. Asexual Reproduction
Asexual – no change in genetic
makeup of daughter cells, all are
identical
Sexual – daughter cells are
genetically different than parents
Gametes
Gametes – sex cells (sperm &
egg), the result of meiosis
Binary Fission
Binary = 2
Fission = split
apart
Asexual
reproduction
Occurs after a
period of growth
Binary Fission Steps
1.
2.
3.
4.
5.
DNA replication (time
frame is minutes or
hours)
Protein synthesis (~ 40
minutes)
Replication of structures
(7 minutes)
Cytoplamic separation &
pinching (7 minutes)
New cell walls form (7
minutes)
DNA
DNA is copied by cell
enzymes (transcription)
Makes 2 copies (looped
DNA)
Cytoplasm
Increase in
metabolism
causes rapid
manufacture of
cytoplasm &
structures
Causes increase
in mass of cell &
length
Effects of Antibiotics
Penicillin acts to weaken
cell wall
Cell wall is so weak that
cell bursts and dies (like
using paper instead of
concrete blocks for
walls)
Only works on growing
cells
Mature cells are NOT
affected
Daughter Cells
“Daughter” is
a misnomer,
but still used
(not female)
Generation Time
Genetically determined, different species
different times to undergo binary fission
Ex: E. coli = 20 minutes
Environment also determines the
generation time (cold temperatures slow
it down)
Measured from the start of one binary
fission event to the start of the next