23. Gene expression at the transcriptional level requires _________________ to b

Question

23. Gene expression at the transcriptional level requires _________________ to bind DNA sequences called _____________________.

A) Transcription DNA: VNTRs

B) Transcription Factors: STRs

C) Transcription Factors: promoters

D) Transcription RNA: promoters

E) None of the above

24. Which is the enzyme responsible for carrying out transcription (DNA -> RNA)?

A) RNA replicase

B) RNA polymerase

C) DNA polymerase

D) RUBISCO

E) none of the above

25. In science, a theory is

a. something that is always true

b. explanation for natural phenomena supported by many lines of evidence

c. a concept that you try to prove experimentally

d. a guess based on previous observations

Explanation / Answer

Ques-1:

23. Gene expression at the transcriptional level requires _________________ to bind DNA sequences called _____________________.

Answer: C) Transcription Factors: promoters

Reason:

These three-RNA polymerase system enable eukaryote to promote "profound protein synthesis" to break down macromolecules & to synthesize macromolecules efficiently as eukaryotes are more complex compared to simple single celled prokaryotes & single celled eukaryotes.

RNA polymerase I: This is going to code for large rRNA precursors, 28S, 5.8S, and 18S rRNAs are mainly coded in eukaryotes by RNA polymerase along with mRNA, tRNA

RNA polymerase II: This is going to promote DNA to code for mostly proteins

RNA polymerase III: This is going to promote synthesis of tRNAs including a few snRNAs. This is also going to promote synthesis of 5S ribosomal - RNA along with some small functional RNAs.

Eukaryotic transcription: The three steps in eukaryotic transcription inside the nucleus of a cell include the following.

1. Initiation; 2. Elongation; 3. Termination

Initiation: Transcription is the process of synthesis of RNA from DNA in the presence of RNA polymerase inside the nucleus. Transcription is initiated by the binding of transcription factors and RNA polymerase II in eukaryotic cell nucleus where promoter region (GC rich region, TATA box) of DNA is located. Promoters are base pair sequences of DNA that potentially enable binding of RNA polymerase II to initiate transcription by unzipping the DNA for protein synthesis.

TATA-binding Protein (TBP): TATA-less promoters promotes transcription by promoting RNA polymerase type II using other factors such as nuclear proteins Transcription factor TFIIA during the transcription of DNA. Pre-initiation complex formed by TBP in the eukaryotic DNA (A- T rich TATA box absent) 35 nitrogen bases upstream followed by DNA melting due to formation of negatively charged bonding with DNA backbone using arginine and lysine amino acid residues of TBP. In this manner DNA –TBP protein interaction promotes transcription-using type II RNA polymerase using other transcription factors such as SL1, TFIIB, TFIIC, and TFIID.

24. Which is the enzyme responsible for carrying out transcription (DNA -> RNA)?

Answer: B) RNA polymerase

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.