Exam 2 Review - Mutations and Gene Regulation

These flashcards cover key concepts about mutations, gene regulation in prokaryotes, and eukaryotic transcription control related to an upcoming exam.

What are mutations classified by?

Mutations can be classified by the chromosomes or proteins they affect.

What is an induced mutation?

An induced mutation is caused by mutagens, which are environmental factors like chemicals and radiation that alter DNA structure.

What is the difference between somatic mutations and germline mutations?

Somatic mutations occur in somatic body cells, while germline mutations occur in cells that give rise to gametes.

What is a missense mutation?

A missense mutation is a mutation that changes the sequence of amino acids in the protein.

What is the role of the lac operon in gene regulation in prokaryotes?

The lac operon is an inducible operon that regulates gene expression in bacteria, allowing transcription to occur when lactose is present.

What is meant by 'positive regulation' in gene expression?

Positive regulation is when certain factors enhance the transcription of genes, often in response to specific signals.

What is the impact of DNA methylation on gene expression?

DNA methylation can repress gene expression by altering the binding of transcription factors and RNA polymerase to DNA.

What is the difference between euchromatin and heterochromatin?

Euchromatin is loosely packed and transcriptionally active, while heterochromatin is tightly packed and generally transcriptionally inactive.

What is a nonsense mutation?

A nonsense mutation stops the protein from being produced by creating a premature stop codon.

How does the presence of glucose affect the expression of lac genes?

The expression of lac genes is dependent on the absence of glucose and the presence of allolactose.

What are transcription factors?

Transcription factors are proteins that help initiate and regulate the transcription of genes.

What happens during the lytic cycle of viral reproduction?

During the lytic cycle, viruses replicate within the host cell and eventually burst out to infect other cells.

What is the role of histone acetylation in gene regulation?

Histone acetylation activates transcription by reducing the strength of the interaction between histones and DNA.

What is a silent mutation?

A silent mutation is a mutation that does not change the protein at all.

What do general transcription factors do?

General transcription factors bind to the promoter region and assist RNA polymerase in finding the promoter for transcription initiation.

What is a transcription elongation regulation?

Transcription elongation regulation is a mechanism by which the host cell can prevent the viral transcription process after it begins.

What is the effect of allolactose on the lac repressor?

Allolactose binds to the lac repressor, inhibiting it and allowing transcription of the lac operon to begin.

What is the significance of viral early genes during infection?

Viral early genes are transcribed first to produce proteins that regulate the host's machinery for viral reproduction.