DNA 2 - MT2 - Part 1 Flashcards
Polymorphism
Is an inherited character from which different traits are present in a population
What are 3 examples of polymorphisms?
- Mouse fur colour
- Human eye colour
- Human blood type
Where is DNA polymorphism located?
On a specific chromosome that has appreciable variation in a population
What are genes and the expression of genes in an organism basic to? (2)
- Morphology
2. Functioning of the organism
What can DNA sequence be irrelevant in determining?
The organisms observable properties
What do many polymorphisms have nothing to do with?
Determining the characteristics of the organism that carry from one individual to another
What are 3 types of DNA polymorphism?
- SNP
- VNTRs
- STR
SNP
Single nucleotide polymorphism
Single nucleotide polymorphism
Is a site where different base pairs are found in different individuals
- the sight might be part of a gene or might be outside the gene sequences
VNTRs
Variable number of tandem repeats
STR
Short tandem repeats
What are VNTR regions?
Sites in the genome where a short DNA sequence (15-100bps long) is repeated over a distance of 1000-20,000 bp
What are STR regions?
Is similar to VNTR region, except that the repeated sequence is 2-9bp long and is repeated 7-40 times
- its a lot shorter
- the repeat number is polymorphic but the flanking sequence are not
What does each STR region have? (2)
- An unique name
2. Chromosome location
What do no 2 people have the same of?
Chromosome repeats
- expect maybe identical twins
What are 6 sources of DNA?
- Blood
- Semen
- Hair
- Bits of tissue
- Saliva
- bones
When should you use VNTR loci?
When there is a lot of source tissue and a lot of DNA is available
- DNA needs to be largely intact
- not used very much anymore
Southern blot
Is a method used in molecular biology for detection of a specific DNA sequence in DNA samples
What is souther blot a combination of? (2)
- Electrophoresis
- Hybridization
- combines transfer of electrophoresis separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization
What are the 6 steps in southern blotting?
- DNA digestion
- Gel electrophoresis
- Blotting
- Probe labeling
- Hybridization and washing
- Detection
What can restriction enzymes do?
They can cut DNA at specific sequences
- different restriction enzymes recognize and cut different sequences
- wanted the ability to move genes around
When do you use STR loci?
When a small amount of DNA is available
- the procedure involves PCR amplification of the STR region, using flanking sequences as primers and direct detection of the amplified DNA on a gel
What does 1 peak in the STR loci mean?
Homozygous
What does 2 peaks in the STR loci mean?
Heterozygous
