l6 forensic bio Flashcards
Acid phosphatase
An enzyme found in high concentration in semen.
Agglutination
The clumping together of red blood cells by the action of an antibody.
Allele
Any of several alternative forms of a gene located at the same point on a particular pair of chromosomes; for example, the genes determining the blood types A and B are alleles.
Antibody
A protein that destroys or inactivates a specific antigen; antibodies are found in the blood serum.
Antigen
A substance, usually a protein that stimulates the body to produce antibodies against it.
Antiserum
Blood serum that contains specific antibodies
Aspermia
The absence of sperm; sterility in males.
Chromosome
A rodlike structure in the cell nucleus, along which the genes are located; it is composed of DNA surrounded by other material, mainly proteins.
Deoxyribonucleic acid (DNA)
The molecules carrying the body’s genetic information; DNA is double stranded in the shape of a double helix.
Egg
female reproductive cell
Erythrocyte
A red blood cell
Gene
A unit of inheritance consisting of a DNA segment located on a chromosome.
Genotype
The particular combination of genes present in the cells of an individual.
Hemoglobin
A red blood cell protein that transports oxygen in the bloodstream; it is responsible for the red color of blood.
Heterozygous
Having two different allelic genes on two corresponding positions of a pair of chromosomes.
Homozygous
Having two identical allelic genes on two corresponding positions of a pair of chromosomes.
Hybridoma cells
Fused spleen and tumor cells; used to produce identical monoclonal antibodies in a limitless supply.
Locus
The physical location of a gene on a chromosome.
Luminol
The most sensitive chemical test that is capable of presumptively detecting bloodstains diluted to as little as 1 in 100,000; its reaction with blood emits light and thus requires the result to be observed in a darkened area.
Oligospermia
An abnormally low sperm count.
Monoclonal antibodies
A collection of identical antibodies that interact with a single antigen site.
Phenotype
The physical manifestation of a genetic trait such as shape, color, and blood type.
Plasma
The fluid portion of unclotted blood.
Polyclonal antibodies
Antibodies produced by injecting animals with a specific antigen; a series of antibodies is produced responding to a variety of different sites on the antigen.
Precipitin
An antibody that reacts with its corresponding antigen to form a precipitate.
Serology
The study of antigen–antibody reactions.
Serum
The liquid that separates from the blood when a clot is formed
Sperm
Male reproductive cell
X chromosome
Female sex chromosome
Y chromosome
Male sex chromosome
Zygote
The cell arising from the union of an egg and a sperm cell
amelogenin gene
A genetic locus useful for determining sex of a DNA contributor
amino acids
The building blocks of proteins; there are 20 common amino acids; amino acids are linked to form a protein; the types of amino acids and the order in which they’re linked determine the character of each protein.
buccal cells
Cells derived from the inner cheek lining
Chromosome
A rod-like structure in the cell nucleus, along which the genes are located; it is composed of DNA surrounded by other material, mainly proteins.
complementary base pairing
The specific pairing of base A with T and base G with C in double-stranded DNA
Electrophoresis
-technique for separating molecules
-electric current is used to move the molecules through a gel or other matrix
epithelial cells
The outer layer of skin cells; these DNA-bearing cells often fall off or are rubbed off onto objects retrieved from crime scenes
human genome
total DNA content found within the nucleus of a human cell
Hybridization
The process of joining two complementary strands of DNA to form a double-stranded molecule.
Low copy number
Fewer than 18 DNA-bearing cells.
Mitochondria
-structures supply energy to the cell
-maternally inherited DNA is found in each mitochondrion
Nucleotide
The unit of DNA consisting of one of four bases—adenine, guanine, cytosine, or thymine—attached to a phosphate–sugar group.
Multiplexing
A technique that simultaneously detects more than one DNA marker in a single analysis.
Picogram
One-trillionth of a gram, or 0.000000000001 gram.
Polymer
A substance composed of a large number of atoms; these atoms are usually arranged in repeating units, or monomers.
polymerase chain reaction (PCR)
-technique for replicating or copying a portion of a DNA strand outside a living cell
-leads to millions of copies of the DNA strand.
Primer
A short strand of DNA used to target a region of DNA for replication by PCR.
Proteins
Polymers of amino acids that play basic roles in the structures and functions of living things.
Replication
The synthesis of new DNA from existing DNA.
Restriction fragment length polymorphisms (RFLPs)
Different fragment lengths of base pairs that result from cutting a DNA molecule with restriction enzymes
Sequencing
A procedure used to determine the order of the base pairs that constitute DNA
short tandem repeat (STR)
A region of a DNA molecule that contains short segments consisting of three to seven repeating base pairs
substrate control
An unstained object adjacent to an area on which biological material has been deposited.
tandem repeat
A region of a chromosome that contains multiple copies of a core DNA sequence that are arranged in a repeating fashion.
touch DNA
DNA from skin cells transferred onto the surface of an object by simple contact
Y-STRs
Short tandem repeats located on the human Y chromosome.
t/f tandem repeats are useful for forensic scientists because they provide a way to distinguish one individual from another through DNA typing
true
advantages of working with short DNA fragments? (3pts)
- more stable, less likely to break apart
- quantity can be greatly amplified by PCR tech
- less subject to degradation due to adverse environmental conditions
which blood components are directly pertinent to the forensics aspects of blood identification? Why?
blood serum: contains antibodies and hormones that can provide info
red blood cells: carry antigens that determine blood types
t/f mitochondrial DNA is found in the nucleus of each cell and is inherited from both parents
false
the D antigen is also known as the …. antigen?
Rh
a paternity test is done involving a woman with type AB blood who has accused a man with type B blood of fathering her child who has tested AB. what can be determined in this case?
male could have fathered the child
what is a presumptive test?
indicate the possible presence of a substance, body tissue, or fluid, but they don’t definitively identify it, usually preliminary test
two commonly used_____ tests for blood are the Kastle-Meyer test and the Hemastix test
presumptive
which statement about mitochondrial DNA is incorrect?
a. located outside the cell’s nucleus
b. constructed in a loop configuration
c. many copies of it’s hypervariable regions are made by PCR
d. number of repeat segments found in the hypervariable regions are used to type mitochondrial DNA
d. number of repeat segments found in the hypervariable regions are used to type mitochondrial DNA
___ regions of mitochondrial DNA have been found to be highly variable in the human population for forensic determination
two
the presence of ___ indicates that a stain is seminal in nature
p30, an antigen specific to prostate and found in semen
the standard test used to determine whether blood is of human or animal origin is the___ test
precipitin
where are antibodies found?
in blood serum
t/f aspermia is an abnormally low sperm count
false
DNA is a..?
polymer
what is the difference between blood plasma and blood serum?
both liquid components of blood
-serum is plasma without clotting factors
-plasma retains clotting factors
