10.3 Sampling DNA variation in a genome

Question 1

What is meant by “ SSR loci are highly polymorphic”?

Answer 1

SSR exhibit a high degree of variability in the number of repeat units among individuals in a population. Many alleles exist in the population. A person carries only two alleles at a given locus

Question 2

What is the process of DNA fongerprinting

Answer 2

DNA fingerprint is unique to any one individual, except identical twins
To examine 13 SSR’s at the same time, you would label the 13 primers with dyes that fluoresce in different colours, and the combine all the primer pairs in the same PCR reaction tube
After gel electrophoresis, you could then identify the allelic variants for each SSR locus based on the fluorescent colours and sizes of the PCR products

Question 3

What is the purpose of COIDS database that is maintained by the FBI?

Answer 3

It is a database that keeps record of people’s DNA fingerpritning which could match someone at a crime scene or prove innocence. It keeps data from all 13 SSR loci

Question 4

What kind of PCR is used for DNA fingerprinting?

Answer 4

Multiplex PCR

Question 5

Short hybridization probes can distinguish single-base mismatches:

Answer 5

Hybridization of short (< 40 bases) oligonucleotides to sample (target) DNAs (allele-specific hybridization)
If there is no mismatch between probe and target, hybrid will be stable at high temperature
If there is a mismatch between probe and target, hybrid will not be stable at high temperature

Question 6

What probes are used on microarrays for genotyping?

Answer 6

hybridization probes: are short, single-stranded sequences of nucleic acids (either DNA or RNA) that are used in molecular biology to detect the presence of complementary sequences (target sequences) in a sample.

Question 7

Allele-specific oligonucleotides(ASO) are _____________________________

Answer 7

attached to a solid support (like a silicon chip)

Question 8

Genomic DNA is used to probe the __________

Answer 8

ASO chip (microarray)

Question 9

What are steps of preparing genomic DNA:

Answer 9

1. Fragmented
2. Adapter attached
3. Amplified by PCR and denatured to make single stranded
4. Fluorescent dye coupled to end of single-stranded DNA