Download Bacterial Reproduction

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1/6/2014
Probity: virtue, integrity
Task: Copy the drawing below. Identify the
organism. Label the areas identified by
arrows.
Hint: small
“hairs”
Hint: outer
cover
Hint:
used for
moving
Hint: inner
lining
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Most difficult: loop of
DNA
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Bacterial Reproduction
Introduction
Bacteria can reproduce in one of two ways:
1.
Asexually
2.
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Sexually
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Asexual Reproduction
Binary Fission:


one parent involved
offspring are identical to parent & each other
Advantages:
1. simple: only 1 parent
2. offspring are fully formed (no maturation needed)
3. very fast (20 min. in ideal conditions)

after 24 hrs:
1 bacterium
2x106 kg of cells
(enough to cover the earth)
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Asexual Reproduction
Disadvantages:
• no genetic variety
• one unfavourable environmental condition can wipe out
whole population
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Asexual Reproduction
Binary Fission:
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Asexual Reproduction
Binary Fission:
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Sexual Reproduction
two parents involved
 offspring are genetically different
to parents & to each other
Advantages:
 genetic variety i.e. some are able to adapt to
unfavourable conditions (ex: antibiotic resistance)

Disadvantages:
1. more complex: slower because must find a
compatible partner
2. no new individuals produced
(i.e. no increase in population)
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Bacterial Conjugation
donor recipient
cell (+)
cell ( - )
plasmid
• plasmid copies itself
• passes through pili
(cytoplasmic bridge) into
recipient cell
pili
• cells separate with both
cells containing the
plasmid
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Homework



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In text book: read pages 148-149
Quiz Wednesday
Test Friday
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