Session 3 Flashcards
Define a locus
Chromosomal position or location of a gene or DNA marker in a non coding region.
List differences between nDNA and mtDNA
- nDna is circular. Mt is linear
- Ndna is diploid.mtdna is haploid.
- Ndna fer generational recombinantion.
Mtdna non.( li paa fer cross over ) - Ndna ena mechanisms of replication repair.mt non.
- Donc nou kav deduce ki ndna ena moins risk of mutation ki mtdna.
- Ndna unique to the person.( except dan banes monozygotic twins ) mtdna li same as maternal relatives.
Define homologous chromosomes .
Consists of 1 maternal and 1 paternal chromosome.They are similar but not identical.Each having the same genes in the same order but the alleles for each trait may not be the same.
1 trait = how many alleles?
2 alleles
What is the name for the alternative possibilities for a genetic locus?
Alllele
Define recombination
Process by which progeny derives a combination of genes different from that of either parent.
NOMENCLATURE FOR DNA /GENETIC MARKERS
1. If marker is part of a gene ______?
2. If marker is not in protein coding region?
3. DNA markers falling outside the gene regions ?
Eg DYS19. Interprete!
- The gene name is used for designation.
- We put the gene name followed by the location of the eg STR and within which intron it is . Eg………..Genename+intron#
- Are designated by their chromosomal position.
1st chunk : D stands for DNA
2nd chunk : Y for chromosome number or X or Y
3rd chunk : S for single copy sequence
4th chunk : in order of discovery of locus.
Pou fer mapping of genetic markers to a chromosome location, ki phase of cell division nou soizir?
Just before metaphase akoz chromosomes condense into more compact form that can be observed under light microscope.
Interprete this : 12p3
Band 3 on the petite arm of chrm12
Prefix HUM
To indicate that it is from the human genome
Number of bp in the haploid human genome?
3billion
How many protein coding genes in the haploid human genome?
21k-25k
What is the rationale of naming chromosomes 1-23 etc ?
Their decreasing size.
Y is the smallest chromosome.
How large is mitochondrial DNA?
How many protein coding regions?
How many tRNA genes?
16,569bp
13 protein coding regions
22
Whats the origin of mtDNA?
Bacterial
How many copies of mtDNA per mitochondrion?
Several depending on cell type
How many mitochondria per cell?
Many, from 10’s to 100’s depending on cell type
How are mitochondria segregated between daughter cells during cell division?
Cytoplasmic segregation – no precise mechanism, roughly equal numbers in daughter cells
- Give a method of sequencing DNA
- Give a method of identifying transcripts
- Give a 4 methods of identifying disease-associated genes.
- Sanger Dideoxy method, second generation DNA sequencing : eg 454 life sciences , 3rd generation DNA sequencing: Heliscope Single molecule sequencer and pacific biosciences smrt , 4th generation DNA sequencing.
- Northern Blot Hybridisation ,Reverse Northern Blot,RT-PCR, quantitative PCR to evaluate transcript levels.
- Linkage analysis,GWAS, Identification of chromosomal abnormalities, Genomic DNA sequencing
Differentiate between :
SNPs and STRs
Processed pseudogenes and non processed pg
Processed pseudogenes and noncoding genes?
SNPs :
STRs:
In 2002-2007 : International Haplotype Mapping Project (HapMap). What was the purpose of Hap Map?
to better understand normal genetic variation among different individuals by examining millions of SNPs in 270 individuals representing 4 population groups.
Thanks to the asymmetric distribution of nucleotides, what happens to the strands? ( in mtDNA)
We get two strands. A heavy and a light strand.
