DNA vocab

DNA

the molecules carrying the body’s genetic information

chromosome

a rod like structure in the cell nucleus along which the genes are located and it’s composed of DNA surrounded by other materials, mainly proteins

polymer

a substance composed of a large number of atoms; these atoms are usually arranged in repeating units, or monomers

nucleotide

the unit of DNA consisting of one of four bases—adenine, guanine, cytosine, or thymine—attached to a phosphate-sugar group

complementary base pairing

the specific pairing of base A with T and base C with G in double-stranded DNA

proteins

polymers of amino acids that play basic roles in the structures and functions of living things

amino acids

the building blocks of proteins

human genome

the total DNA content found within the nucleus of a human cell; it is composed of approximately three billion base pairs of genetic information

repliction

the synthesis of new DNA from existing DNA

polymerase chain reaction (PCR)

a technique for replicating or copying a portion of a DNA strand outside a living cell; the technique leas to millions of copies of the DNA strand

primer

the short strand of DNA used to target a region of DNA for replication by PCR

hybridization

the process of joining two complimentary strands of DNA to form a double stranded molecule

tandem repeats

a region of a chromosome that contains multiple copies of a core DNA sequence that are arranged in a repeated fashion

restriction fragment length polymorphisms

different fragment lengths of base pairs that result from cutting a DNA molecule with restriction enzymes

short tandem repeat

a region of a DNA molecule that contains short segments consisting of three to seven repeating base pairs

electrophoresis

a technique that uses an electrical field within a gel to separate molecules by their size and charge

multiplexing

a technique that simultaneously detects more than one DNA marker in a single analysis

amelogenin gene

a genetic locus useful for determining gender

V-STR’s

short tandem repeats located on the human Y chromosome

mitochondria

small structures located outside the nucleus of a cell; supply energy to the cell; maternally inherited

sequencing

a procedure used to determine the order of the base pairs that constitute DNA

picogram

one-trillionth of a gram

low copy number

fewer than 18 DNA-bearing cells

epithelial cells

the outer layer of skin cells; these DNA-bearing cells often fall off or rubbed off onto objects retrieved from crime scenes

touch DNA

DNA from skin cells transferred onto the surface of an object by simple contact

substrate control

an unstained object adjacent to an area on which biological material has been deposited

buccal cells

cells derived from the inner cheek lining