Transcription Initiation: Sigma and General Transcription Factors

The video tutorial explains the process of transcription, focusing on the role of RNA polymerase in synthesizing mRNA from DNA. It covers the basics of RNA polymerase, its types, and its function in both prokaryotic and eukaryotic cells. The tutorial details the stages of transcription: initiation, elongation, and termination, highlighting the complexity of these processes, especially in eukaryotes. It also discusses the importance of transcription factors, such as the sigma factor in prokaryotes, and their role in facilitating RNA polymerase binding to DNA.

What is the primary role of mRNA in gene expression?

• To store genetic information

• To carry genetic information to ribosomes

• To synthesize DNA

• To degrade proteins

Where is RNA polymerase primarily located in eukaryotic cells?

• Nucleus

• Endoplasmic reticulum

• Mitochondria

• Cytoplasm

Which of the following is NOT a type of RNA polymerase found in humans?

• RNA polymerase I

• RNA polymerase IV

• RNA polymerase II

• RNA polymerase III

What are the three main processes involved in transcription?

• Elongation, Termination, Replication

• Initiation, Elongation, Termination

• Transcription, Translation, Replication

• Replication, Translation, Termination

In prokaryotes, which transcription factor is crucial for initiating transcription?

• Sigma factor

• Gamma factor

• Beta factor

• Alpha factor

What is the role of the sigma factor in prokaryotic transcription?

• To bind RNA polymerase to DNA

• To terminate transcription

• To degrade RNA

• To synthesize mRNA

Which region does the sigma factor bind to in prokaryotic DNA?

• -5 and -15 regions

• -20 and -40 regions

• -30 and -50 regions

• -10 and -35 regions

What replaces the sigma factor during the elongation phase in prokaryotes?

• NusA

• NusB

• NusC

• NusD

Which transcription factor binds to the TATAAA box in eukaryotes?

• Transcription factor 4C

• Transcription factor 3B

• Transcription factor 2D

• Transcription factor 1A

How do general transcription factors in eukaryotes compare to sigma factors in prokaryotes?

• They only bind to RNA

• They are identical in function

• They are more complex and numerous

• They are less important