Term
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Definition
-E. coli genome is circular ds DNA
-isn't a chromosome
-found in a structure called a nucleoid
-some are linear |
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Term
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Definition
occurs when additional turns are introduced into the double helix (positive) or turns are removed (negative)
-circular DNA responds by winding around itself for smaller spaces |
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Term
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Definition
| 40 to 50 supercoils around the protein core |
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Term
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Definition
-not absolutely essential under normal conditions
-can be ultimately dispensed; but have much of their DNA in plasmid form |
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Term
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Definition
| packed with genes, less than 5 MB |
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Term
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Definition
group of genes involved in a singled biochemical pathway and expressed in conjunction with one another
-not all genes of an operon are related |
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Term
| minimum number of genes necessary to maintain a living cell |
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Definition
-300 genes
-free living cell is capable of living on/in something |
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Term
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Definition
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Term
| lateral or horizontal gene flow |
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Definition
transfer of genes between species, even between highly unrelated species
-happens by means of conjugation, transduction, and transformation |
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Term
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Definition
-usually circular but some linear
-many copies per organelle, and many organelles per cell so you can have thousands of copies per cell |
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Term
| how many genes are in organeller genome |
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Definition
-10-100 genes; majority for respiratory complex, tRNA, and rRNA
-chloroplast have about 200 genes |
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Term
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Definition
-bacteria invaded eukaryotic cells and lived as endosymbionts
-mitochondrial gene segments have been found in chloroplast genomes
-eventually lost most of their genes |
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Term
| Why didn't all of the organeller genes get transferred to the nuclear genome |
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Definition
| some proteins need to be translated in the organelle due to hydrophobic interactions that would be difficult in the cytoplasm |
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