forensic exam Flashcards
what is forensic palynology?
study of pollen and spores
What is a spore?
asexual reproductive structure
found in algae, plants and fungi
Q: How can forensic palynology help in an investigation?
reveal location
where the person might have been season or time of year
How are pollen and spores identified?
morphology using light microscopy or scanning electron microscopy (SEM).
What is the significance of ridge patterns in fingerprint analysis?
The primary ridge patterns are loops, whorls, and arches.
each persons fingerprint is different.
How does touch DNA demonstrate Locard’s Principle of Exchange?
whenever a person comes into contact with an object or surface, they leave behind trace evidence (such as skin cells, hair, or DNA)
Why is it better to focus on non-coding DNA in forensic DNA analysis?
- highly variable between people
- does not affect bodily functions
- provides unique markers that can be used to differentiate between individuals.
Describe the role of DNA polymerase in DNA replication.
enzyme that creates new DNA strands by adding matching nucleotides to the template strand during replication.
What is the function of the promoter region in a gene?
The promoter is a DNA sequence that signals where transcription begins, allowing RNA polymerase to start making mRNA from the DNA template.
What is the role of DNA methylation in gene expression?
- DNA methylation adds methyl groups to DNA, at cytosine bases.
- This can stop genes from being activated by blocking transcription factors (silencing the gene)
What are the symptoms of carbon monoxide poisoning?
why do symptoms occur?
headache, dizziness, confusion, nausea, shortness of breath, sometimes loss of consciousness or death.
occurs because carbon monoxide binds to hemoglobin, preventing oxygen transport.
Describe first stage of decomposition
fresh; begins at death
files start to arrive
temp falls
breakdown of molecules
Describe stage 2 of decomposition
Bloated: Gases from bacteria cause swelling. Fluids ooze, and flies continue to arrive.
Describe stage 3 of decomposition
Decay: Gases subside, and fluids leak out. Maggots break skin, larvae pupate.
The body shrinks to 20% of its mass.
Describe stage 4 of decomposition
Post Decay: Only skin, hair, bones, and teeth remain. Flies are replaced by beetles and mites.
Describe stage 5 of decomposition
Skeletal: In dry conditions, only bones and teeth remain, about 10% of the original body mass.
How can forensic anthropology be used to estimate the age of a deceased individual?
skeletal remains
wear of teeth
fusion of bones
condition of the pubic symphysis.
What is livor mortis?
Livor mortis is pooling of blood in the lowest parts of the body due to gravity after death.
During livor mortis, where would we expect to find lividity in a hanging death?
lower extremities and the upper body
blood pools below the constriction point (e.g., the neck).
what does A always pair with?
always with T
what does C always pair with?
always with G
two types of DNA?
nuclear & mitochondrial
what cells have no nucleus and no mitochondria?
red blood cells
what cells have cell nucleus and many mitocondria?
cheek cells & sperm cells
what is the SRY gene
located in Y chromosome
responsible for instructing embryo to become male
Variable number tandem repeats (VNTRs)
50-1000 repeats of 15-100 nucelotides
short tandem repeats STRs
5-50 repeats of 2-5 nucleotide long sequences
do VNTRs & STRs numbers vary among people?
yes
what is Gel Electrophoresis?
lab technique that carries DNA fragments through a gel using electricity.
what does HETEROzygous mean?
the two alleles are different (eg. 15,19)
what does HOMOzygous mean?
the same allele (eg. 15,15)
what are the first species on corpse tissue?
blowflies and flesh flies
factors affecting oviposition & egg development
temperature lower than 10 degrees
wind
sunlight/shade
rainfall
do not lay eggs at night
