GENES The gene is a nucleic acid sequence that is necessary for function of gene product. Gene may be a protein coding gene whose transcribed RNA is translated into proteins or RNA only genes. Protein coding genes may be solitary or families or tandem repeats NON –CODING SEQUENCE The non coding sequence are genes that do not encode the protein. The amount of non-coding sequence in DNA of organism varies among species. Eg-Human genome -98% non-coding genes Prokaryotes -10% non-coding genes Types of Non coding sequences The non coding sequences can be in the form of following Introns Anti leader and Anti trailer sequence Promoter sequence Enhancers Pseudogenes Gene fragments Telomeres Non-coding functional RNA Cis-Trans regulatory elements INTRONS Introns are non-coding sequence that transcribed into RNA But precursor mRNA removed by splicing during processing. The eukaryotic genome has large amount of introns...
DNA As Genetic material 1. GRIFFTH EXPERIMENT It is also called as as transformation principle . It involve in bacterial transformation. Frederick giffth proposed this experiment. The pneumonia bacteria which causes pneumonia is used for this experiment Strains of bacteria: 1.Rough strain It has rough appearance It is avirulent and non pathogenic It does not have capsule 2.Smooth strain It has smooth glistering appearance It has capsule made of polysaccharide It is virulent pathogenic Strains S types- SI, SII and SIII R types-RI,RII and RIII Both S and R types differ in each other antigen Smooth forms may be mutated to rough forms but the changes are not reversible Procedure Step 1 The laboratory mice inject With live RII pneumonia The mice suffered no illness Because RII pneumonia is avirulent Step 2 But when mice inject with Virulent SIII pneumonia The mice suffere...
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