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The origin of cells

Topic 1
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He boiled a nutrient broth
2
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An open flask
b
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A swan neck flask with distilled water
3
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Margulis 1981
➢ Key points:
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About 2 billion years ago a bacterial cell took up residence inside a
eukaryotic cell

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The eukaryotic cell acted as a “predator” bringing the bacterial cell inside

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The eukaryotic cell and the bacterial cell formed a symbiotic relationship, in
which both organisms lived in contact with one another

1

The origin of cells
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Topic 1
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When it comes in contact with a specific type
of green algae, it enters the adult stage, in which chloroplasts from
the ingested algae are retained in its digestive tract
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Its colour becomes green

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It can carry out photosynthesis

The 64 codons
➢ All genetic molecules include codons that code for different parts of the proteins
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3-letter combination of DNA coding for a specific amino acid

➢ Inj nearly all organisms the same codon makes the same amino acid
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Slight variations, due to evolution

➢ Mitochondria have a DNA code that resembles more bacteria than eukaryotes
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The more DNA two organisms have in common the more closely related
they are to one another
2



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