EXAM 3: ch. 13 Y/mito testing

Question 1

___ provide a higher power of discrimination and are the PREFERRED method whenever possible

Answer 1

autosomal STRs

Question 2

due to capabilities for male specific amplification ___ is useful in female-male mixtures

Answer 2

Y-STR

Question 3

due to high copy number __ may be the only source of surviving DNA in highly degraded/ low quantity specimens (hair)

Answer 3

mitochondrial (mtDNA)

Question 4

Y chromosome DNA analysis uses :

Answer 4

• Y chromosome testing
• Y-STR haplotype databases
• interpretation of results: exclusion, inconclusive, inclusion

Question 5

Mitochondrial DNA analysis uses:

Answer 5

• thousands of copies, 37 gene products and non coding regions
• heteroplasmy
• location and structure of mt DNA
• maternal inheritance
• issues with sequence quality

Question 6

why are autosomal DNA markers shuffled with each generation?

Answer 6

because 1/2 comes from each parent

Question 7

__ and ___ markers are passed down from generation to generation without changing (except mutation)

Answer 7

Y and Mitochondrial

Question 8

___ lineages can be traced via mitochondrial DNA sequences and ___ can be followed via Y markers

Answer 8

maternal
paternal

Question 9

why are genetic markers called “haplotpye”?

Answer 9

because there is only a single allele

Question 10

where is Y used?

Answer 10

• forensic evidence examination (sperm vs epithelial cells)
• paternity testing (find father)
• missing persons (paternal tests as reference)
  -historical and genealogical investigations (Y-STR)
• human migration patterns (Y-SNPs)

Question 11

advantages of Y-STR and mtDNA

Answer 11

advantages:
- extend possible reference samples beyond a single generation( benefit missing persons/geneaology)
- family members have indistinguishable haplotypes unless mutations have occurred

Question 12

disadvantages of Y-STR and mtDNA

Answer 12

• lower power of discrimination due to no genetic shuffling with recombination
• family members have indistinguishable haplotypes unless mutations have occurred

Question 13

advantages of Y

Answer 13

• male specific, can enable male profile in a mixture with high female DNA (sexual assault case)
• additional mixtures (fingernail scrapings, saliva on skin)
• paternity and trace family lineages

Question 14

disadvantages of Y

Answer 14

• cannot be used to distinguish brothers or paternal relatives
• lower discrimination power (no product rule)

Question 15

the Y chromosome has ____ and __ pseudoautosomal regions

Answer 15

“non recombining (NRY)”
2 (PAR 1 and PAR 2)

Question 16

___ combine with the X chromosome

Answer 16

PAR 1 and PAR 2

Question 17

true or false: the Y chromosome has eucharomatic and heterochromatic regions

Answer 17

true

Question 18

Y-SNPS exhibit ___ and Y SNPS ____

Answer 18

• more variability ; haplotypes,higher mutation rate, used in forensic application
• used in ancestry studies (haplogroups)

Question 19

Y chromosome has duplicated palindromic regions so…

Answer 19

some YSTRloci occur more than once, leads to more than one peak