Unit 2 Test Study Guide: Genetic Testing & Screening

Vocabulary and key concepts from the Unit 2 Test Study Guide covering Sanger sequencing, restriction enzymes, and gel electrophoresis.

Sanger Sequencing

A technique used to determine the order of bases (A, T, C, G) in a DNA region.

Template DNA

The DNA whose sequence is being determined in a sequencing reaction.

Primer

A short strand of nucleic acid that provides a starting point for DNA polymerase during DNA synthesis.

DNA Polymerase

An enzyme that builds a new DNA strand by adding nucleotides.

dNTPs

Normal A, T, C, G building blocks that allow DNA synthesis to continue.

ddNTPs

Chain-terminating versions of A, T, C, G where each type is labeled so the ending base can be identified.

3' OH Group

A chemical group lacking in ddNTPs, which prevents the attachment of the next nucleotide and halts strand growth.

Sanger Gel Reading Order

Reading the gel from bottom to top yields the newly synthesized DNA sequence in the $5'$ to $3'$ direction.

Restriction Enzymes

Proteins originally found in bacteria that recognize specific DNA sequences and cut DNA at restriction sites.

Restriction Sites

Specific DNA sequences that are cut by restriction enzymes, often displaying palindromic symmetry when read in the $5'$ to $3'$ direction on both strands.

Linear DNA Fragment Formula

A rule stating that for linear DNA, the $\text{number of fragments} = \text{number of cuts} + 1$.