Estructura molecular de genes y cromosomas

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Copyright (c) by W. H. Freeman and Company Chapter 9 Molecular Structure of Genes and Chromosomes

Transcript of Estructura molecular de genes y cromosomas

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Chapter 9

Molecular Structure of Genes and Chromosomes

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9.5 The solenoid model of condensed chromatin

Figure 9-31

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9.2 Simple-sequence DNAs are concentrated in specific chromosomal locations

Figure 9-6

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9.6 A model for chromatin packing in metaphase chromosomes

Figure 9-35

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9.6 Experimental demonstration of chromatin loops in interphase chromosomes

Figure 9-36

Sites A-F are separated by millions of bp of linear sequence but are physically close to each other in interphase nuclei

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9.6 Heterochromatin consists of chromosome regions that do not uncoil

Figure 9-39

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9.6 Chromosome painting distinguishes each homologous pair by color

Figure 9-0

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9.6 Stained chromosomes have characteristic banding patterns

Figure 9-38

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DEFINICION MOLECULAR DE GEN

Un gen es una secuencia completa de ADN que es necesaria para la sintesis de uno o más polipéptido funcional en un momento determinado.

Regiones de ADN que codifican para moleculas de ARN como ARNt y ARNr tambien son consideradas genes.

En eucariotes, los genes permanecen en medio de segmentos no codificantes, no funcionales de ADN.

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9.1 Simple and complex transcription units are found in eukaryotic genomes

Figure 9-2

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9.2 Genomes of higher eukaryotes contain much nonfunctional DNA

Figure 9-3

Amongst eukaryotes, cellular DNA content does not correlate with phylogeny.

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9.3 The two classes of mobile elements

Figure 9-10

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Los elementos moviles probablemente tienen influencia significativa en la evolución

Mutaciones espontaneas pueden resultar de la inserción de un elemento movil dentro o cerca de una unidad de un gen.

Recombinación homologa entre elementos móviles pueden contribuir a la duplicación u otros re arreglos, incluyendo duplicacion de intrones , recombinación de intrones para creas nuevos genes y control de expresión de genes.

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9.5 Nucleosomes are complexes of histones

Figure 9-30

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9.7 Human mtDNA

Figure 9-44