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3 Cards in this Set
- Front
- Back
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Organisation of DNA into Chromosomes |
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Structure of Chromosomes |
●DNA wrapped round histone protein to fix in to place ●DNA HISTONE complex is coiled X2 which means that long molecules of DNA can be condensed into single chromosome,so lots of genetic info can be stored ●A cell in Interphase has chromosomes dispersed throughout the nucleus so not visible as separate structures ie in prophase ● C can only be seen as a distinct structure when nucleus is about to divide after DNA molecule replicated by S-CR ●each sister chromatic contains a genetically identical DNA molecule ●Diploid Org inherit full set of chromosomes from each parent,so diploid cells have homologous pairs of chromosomes ●Humans have a diploid number 2n=46 , other species differ |
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Karyotype |
●1 member of pair is from mother and is called maternal chromosome the other member Is from the father and called paternal chromosome ● Homologous pairs carry the same genes at the same locus ●But they do not necessarily carry the same alleles of the gene ●Homologous pairs are not genetically identical |
