Honors Biology Unit 6 Final Examm

Semi-Conservative Replication

A process where a new DNA molecule is formed with one original strand and one newly synthesized strand.

DNA Polymerase

An enzyme that adds nucleotides to the 3’ end of the primer, proofreads base pairing, and performs mismatch repair.

Lagging Strand

A strand of DNA synthesized discontinuously, forming small fragments called Okazaki fragments, necessitating its own primer.

Transcription

The process of copying DNA into RNA.

RNA Processing

In eukaryotes, it includes capping, polyadenylation, and splicing to produce mature mRNA.

Initiation (Transcription)

RNA polymerase binds to a specific DNA sequence called the promoter to start transcription.

Elongation (Transcription)

RNA polymerase unwinds the DNA and adds complementary RNA nucleotides to the mRNA strand.

Termination (Transcription)

The process where RNA polymerase encounters a termination sequence, signaling the end of transcription.

Start Codon

A three nucleotide sequence that indicates where protein translation should begin.

Stop Codon

A three nucleotide sequence that signals the ribosome to stop translating mRNA.

RNA Splicing

The process of removing introns and joining exons in eukaryotic cells to create different proteins.

Mutagen

An outside agent that causes a genetic mutation.

Operons

Genetic regulatory systems used by prokaryotic cells to regulate gene expression.

Lac Operons

Inducible operons that require inactivation of a repressor protein to be activated.

Trp Operons

Repressible operons that are normally active and require activation of a repressor protein to be turned off.

Histones

Proteins that regulate gene expression by influencing DNA accessibility to transcriptional machinery.

Nucleosome

A section of DNA wrapped around a core of proteins, also known as chromatin.

Barr Body

An inactivated X chromosome in mammals that prevents aneuploidy.

Transcription Factors

Proteins that bind to specific DNA sequences to activate or repress transcription.

Alternative RNA Splicing

A process where a single gene can produce multiple mRNA transcripts through selective inclusion or exclusion of exons.

What is initiation in the context of transcription?

Initiation refers to the process where RNA polymerase binds to the promoter region of a gene and begins to unwind the DNA, allowing for the synthesis of RNA.

What is elongation during transcription?

Elongation is the phase of transcription where RNA polymerase moves along the DNA template strand, synthesizing RNA by adding ribonucleotides in a 5' to 3' direction