mock exam

Question 1

Which characteristic would NOT be considered as a beneficial as a choice of forensic DNA marker?

Answer 1

dimorphic marker

Question 2

Which class of STR markers are most used for forensic DNA profiling?

Answer 2

tetranucleotide

Question 3

What is the quoted discriminatory power for a full DNA17 profile?

Answer 3

1 in a billion

Question 4

How many STRs are typed using a full DNA17 kit?

Answer 4

16

Question 5

Which “control sample” is used to check that the PCR is working as expected?

Answer 5

Positive PCR control

Question 6

Which sample type would NOT be collected using an indirect swabbing technique?

Answer 6

pubic hair

Question 7

What function does silica have during the DNA extraction?

Answer 7

Binding of DNA for purification

Question 8

Which PCR component would not be entered into every reaction tube?

Answer 8

Template DNA

Question 9

During the polymerase chain reaction, at what temperature is DNA denatured?

Answer 9

95 degrees Celsius

Question 10

What is the specific function of substrate control?

Answer 10

To monitor for background levels of DNA when samples are collected from substrates that are anticipated to have DNA already present on them.

Question 11

What is the specific function of DNA extraction negative control

Answer 11

to monitor for the introduction of DNA contamination during the extraction phase of the laboratory process. A DNA-free swab could be used.

Question 12

What is the specific function of PCR positive control

Answer 12

to ensure that the cr phase of the laboratory process is working correctly. DNA of know quality, quantity and profile would be used.

Question 13

what is the specific function of Environmental control

Answer 13

to monitor for the accumulation of background levels od DNA in the laboratory environment, including workbenches and instrumented

Question 14

What factors need to be considered when designing PCR primers for a new multiplex reaction?

Answer 14

product size - we aim to produce short per product so that there’s more chance the target region is intact

Question 15

Using correct terminology, describe what features e.g. full or partial DNA profile, you would expect to see on a forensic DNA profile electropherogram generated following standard laboratory processing of Buccal cell reference swab collected from a biologically female individual

Answer 15

full female DNA profile xox result at amelogenin marker

Question 16

Using correct terminology, describe what features e.g. full or partial DNA profile, you would expect to see on a forensic DNA profile electropherogram generated following standard laboratory processing of swab from the handle of a handgun recovered from a river

Answer 16

low quantity and low quality dna, with low molecular weight markers, also potentially showing DNA mixture

Question 17

Using correct terminology, describe what features e.g. full or partial DNA profile, you would expect to see on a forensic DNA profile electropherogram generated following standard laboratory processing of Single human head hair, containing no root

Answer 17

no dan profile as only the root of hair contains nuclear DNA

Question 18

Using correct terminology, describe what features e.g. full or partial DNA profile, you would expect to see on a forensic DNA profile electropherogram generated following standard laboratory processing of Swab of a bite mark on a male complainants skin, alleging a female bit him

Answer 18

expect a mixture of male and female DNA. female would be major contributor but may observe full both individuals

Question 19

p2

Answer 19

homozygous dominant allele

Question 20

2pq

Answer 20

heterozygous genotype

Question 21

p2

Answer 21

homozygous recessive