Lecture 9/30 - E2

Question 1

What is the Manhattan Plot?

Answer 1

A plot used to show where SNIPs are above a certain threshold to provide evidence for being associated with disease genes in this region

Question 2

________ ______ ______ generate individual genetic profiles using labratory analysis of carefully selected markers followed by statistical evaluation.

Answer 2

Contemporary Forensic Methods

Question 3

_____ _____ ____ and _____ _____ _____ _____ contain repeateing DNA sequences less than 10bp or more than 10bp long can be used for genomic analysis.

Answer 3

Short tandem repeats (STRs)

Variable number tandem repeats (VNTRs)

Question 4

Are STRs or VNTRs used in forensic analysis?

Answer 4

STRs because of their broad representation

Question 5

What is the Combined DNA Index System (CODIS)?

Answer 5

The FBI’s extensive analysis culminating in selection of 13 independently assorting human STR markers

Question 6

What is the CODIS Marker Criteria?

Answer 6

1. Have known chromosome location
2. Have multiple alleles (8-16) in the population examined
3. Carry alleles that can be accurately amplified by PCR
4. Have distinct PCR product lengths that distinguish alleles from one another

Question 7

What is capillary (tube) gel electrophoresis and why is it used?

Answer 7

Used to automate the analysis of PCR-amplified STR fragments
Uses a florescent dye-tagged nucleotide that is incorporated during each CODIS marker PCR and the resultant DNA band can be detected

Question 8

When given the DNA profile results for the CODIS STRs, what does the horizontal axis indicate?

Answer 8

Fragment length

Question 9

When given the DNA profile results for the CODIS STRs, what do the numbers above the peaks represent?

Answer 9

Repeat length

Question 10

When given the DNA profile results for the CODIS STRs, what do double peaks indicate?

Answer 10

Heterozygous genotype

Question 11

When given the DNA profile results for the CODIS STRs, what do single peaks indicate?

Answer 11

Homozygous genotype

Question 12

When using CODIS for forensic analysis, what does law enforcement usually require?

Answer 12

A minimum of 13 CODIS markers to be scored with at least 10 providing useful information

Question 13

How are STR allele frequencies used?

Answer 13

To determine the probability that another person selected at random has the same genotype

Question 14

What term is defined as the number of copies of the allele in a population divided by the sum of all alleles in that population?

Answer 14

Allele frequency

Question 15

How do you calculated the probability (P) of a heterozygous individual having both alleles at a single locus?

Answer 15

P = 2pq
p and q are frequencies
p is from mom while q is from dad, but it can also be reversed. Therfore, multiple by 2 as well.

Question 16

What is the probability (P) of a genotype in a homozygous individual with an allele frequency p?

Answer 16

P = p^2

Question 17

How do you calculate the joint probability that a genotype will have a certain distribution at random?

Answer 17

Multiply all the genotype frequencies

Question 18

What are some of the issues related to crime scene DNA analysis?

Answer 18

DNA does not necessarily mean that the accused individual is guilty of any crime, only that the person was likely present