Difference between revisions of "Libre Pathology talk:Study Group"

{{hidden|List three differences between DNA and RNA.|[[DNA (double stranded, thymine, deoxyribose, more stable; RNA single stranded, ribose, uracil]]}}

 

 

 

 

 

{{hidden|List three differences between somatic and germline mutations. |<center>[[Somatic: not passed on to progeny, only tumour or particular tissue cells with mutation, Germline: passed onto progeny, all cells have mutation * unless mosaicism or chimerism]]</center>}}

 

{{hidden|What is the difference between a missense and a non-sense mutation?|<center>[[Missense the new base pair does not change the amino acid found in the protein at that location, non-sense changes the amino acid in the protein at that location]]</center>}}

{{hidden|Define a frameshift mutation. |<center>[[deletion of a non-multiple of 3 which causes all further trinucleotide combinations to no longer code for the correct amino acid, often results in a premature stop codon]]</center>}}

{{hidden|Why are inversion mutations difficult to detect?|<center>[[When the are smal, e.g. only a few base pairs]]</center>}}

{{hidden|Describe the potential sequelae of a translocation mutation. |<center>[[when a segment on one chromosome is transferred to another, make a gene non-functional or can result in a fusion gene]]</center>}}

{{hidden|Translate the following: c.1524_1527delCGTA.|<center>[[a small deletion  of CGTA between the 1524 and 1527 base pairs]]</center>}}

{{hidden|List 5 features of SNPs.|<center>[[most common DNA sequence variation in humans, must occur in >=1% of a particular population, frequency of SNPs varies by groups, but responsible for >90% of human genetic variation, an can be found in any region of genome]]</center>}}

{{hidden|Define a regulatory SNP and a synonymous SNP?|<center>[[Regulatory SNP: occur in non-coding regions e.g. promoters where they affect mRNA expression and stability, as occur in the splice site where can result in abnormal protein production]</center>}}

{{hidden|What is the difference between a microstalellite and a minisattelite?|<center>[[Microsatellite = stretches of DNA with sequences of 2-4 base pairs repeated a few dozen times (STRP), minisatellite = variable number of tandem repeats 10-100bp in lenght]]</center>}}

{{hidden|Describe Hardy-Weinberg Equilibrium?|<center>[[Mathematical probability function to describe allelic and genotype frequency in a random mating scenario]]</center>}}

{{hidden|What factors can disrupt the H-W equilibrium?|<center>[[non random mating, migration, genetic drift, founder effects, mutation, natural selection]]</center>}}

{{hidden|What is linkage disequilibrium?|<center>[[The closer two genes are together on the chromosome the more likely they are to be found toghether in a population, during meiosis some exchange of material happens between the two chromosomes]]</center>}}

{{hidden|What are the three major steps of PCR?|<center>[[denaturing, primer annealing, strand extending]]</center>}}

{{hidden|What is the hallmark of PCR?|<center>[[The cycling at different temperatures, in the presence of key reaction components to traget and exponentially amplify a specific DNA target sequence]]</center>}}

{{hidden|What factors affect the method of genotyping chosen?|<center>[[throughput, type of variants that can be genotyped, equipment and costs, TAT, technical expertise, and multiplex ability]]</center>}}

{{hidden|Define sensitivity, specificity, positive predictive value and negative predictive value. |<center>[[Sensitivity = probability of a positive test in a disease, specificity = probability of a negative dest in a non-diseased patient ]]</center>}}

{{hidden|Define reproducibility and accuracy of an analytical test. |<center>[[Reproducability = probability of the test repeatedly producing the same reults in the same person, Accuracy = the degree to which the observed genotype matches the true genotype]]</center>}}

{{hidden|Describe briefly Sanger sequencing.|<center>[[DIdeoxynucleotides are used in a mix with deoxynucleotides, the Di*** terminate the chain, and so you get all possible lengths of chains so then you put them all in order and you can read (based on weight) which one is at each position]]</center>}}