DNA Vocab

DNA

The molecules carrying the body's genetic information.

Chromosome

A rod-like structure in the cell nucleus where genes are located; composed of DNA and proteins.

Polymer

A substance made up of a large number of atoms arranged in repeating units called 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, composed of approximately three billion base pairs of genetic information.

Replication

The synthesis of new DNA from existing DNA.

Polymerase Chain Reaction (PCR)

A technique for replicating a portion of a DNA strand outside a living cell, resulting in millions of copies of the DNA strand.

Primer

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

Tandem Repeats

A region of a chromosome that contains multiple copies of a core DNA sequence arranged in a repeating fashion.

Restriction Fragment Length Polymorphisms

Different fragment lengths of base pairs resulting from cutting a DNA molecule with restriction enzymes.

Short Tandem Repeat

A region of a DNA molecule with 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.

Amelogenin Gene

A genetic locus useful for determining gender.

Y-STRs

Short tandem repeats located on the human Y chromosome.

Mitochondria

Small structures located outside the nucleus of a cell that supply energy to the cell and are maternally inherited.

Sequencing

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

Picogram

One-trillionth of a gram.

Epithelial Cells

The outer layer of skin cells that bear DNA and often fall off or are rubbed off onto objects retrieved from crime scenes.

Substrate Control

An unstained object adjacent to an area where biological material has been deposited.

Buccal Cells

Cells derived from the inner cheek lining.

Multiplexing

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

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.

Touch DNA

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