DNA Fingerprinting

Vocabulary flashcards based on DNA fingerprinting lecture notes.

DNA (Deoxyribonucleic Acid)

The genetic material in our cells; no two people (except identical twins) have the exact same DNA.

DNA Fingerprinting (DNA Profiling)

A technique used by scientists to distinguish between individuals of the same species using samples of their DNA.

Alec Jeffreys

English geneticist who invented the process of DNA fingerprinting at the University of Leicester in 1985.

Trace Evidence

Small amounts of biological evidence left at crime scenes; the source of DNA needed for DNA fingerprinting.

Biological Evidence

Includes saliva, blood, semen, skin, hair roots, body tissue cells, and urine.

Chromosomes

Structures in the nucleus of cells that contain DNA; most human cells have 23 pairs (46 total).

Genes

Smaller segments within chromosome pairs that control the traits of an organism and can vary between individuals.

Nitrogenous Bases

Adenine (A), Thymine (T), Guanine (G), and Cytosine (C); form pairs according to the base pairing rule (A-T, C-G).

Base Pairing Rule

Adenine (A) binds only with Thymine (T), and Cytosine (C) binds only with Guanine (G).

Double Helix

The shape of DNA, where two strands twist together; sides are made of sugar and phosphate, and rungs are made of paired nitrogenous bases.

Deoxyribose

The sugar in DNA, from which DNA gets its name.

Nuclear DNA

DNA in chromosomes, inherited from both parents, and virtually identical in all cells of an individual’s body.

Mitochondrial DNA

DNA in the form of a circular loop, inherited only from the mother.

Human Genome

The total amount of DNA in a cell, contained in both the nucleus and mitochondria; consists of approximately 3 billion base pairs.

Exons

Encoded DNA with directions to build molecules; make up only 1.5% of the genome and code for about 24,000 genes.

Introns

Un-encoded DNA that does not code for the production of molecules; makes up 98.5% of DNA and may function in gene splicing.

Polymorphisms

Non-coded DNA segments that contain unique patterns of repeated base sequences that are unique to individuals.

Variable Numbers of Tandem Repeats (VNTR)

Repeating DNA sequences that are 9 to 80 bases in length.

Short Tandem Repeats (STR)

Repeating DNA sequences that are 2 to 5 bases in length.

PCR (Polymerase Chain Reaction)

A technique that makes thousands of copies of segments of DNA that investigators want to analyze.

Primers

Short segments of complimentary DNA that base-pair with the template DNA upstream of the region of interest and serve as recruitment sites for the polymerase

Gel Electrophoresis

A process that separates RFLPs according to their length, creating a DNA Fingerprint.

CODIS (Combined DNA Index System)

The United States’ Electronic database of DNA profiles.