exam 3 part 3

The sigma subunit of bacterial RNA polymerase: a) contains the catalytic activity of the polymerase. b) remains part of the polymerase throughout transcription. c) recognizes promoter sites in the DNA. d) recognizes transcription termination sites in the DNA.

(c) recognizes promoter sites in the DNA

Which of the following statements is FALSE? (a) A new RNA molecule can begin to be synthesized from a gene before the previous RNA molecule's synthesis is completed. (b) If two genes are to be expressed in a cell, these two genes can be transcribed with different efficiencies. (c) RNA polymerase is responsible for both unwinding the DNA helix and catalyzing the formation of the phosphodiester bonds between nucleotides. (d) Unlike DNA, RNA uses a uracil base and a deoxyribose sugar.

(d) Unlike DNA, RNA uses a uracil base and a deoxyribose sugar

Which of the following choices best describes how transcription occurs? a) The top strand is the template strand; RNA polymerase moves along this strand from 5¢ to 3¢ . b) The top strand is the template strand; RNA polymerase moves along this strand from 3¢ to 5¢. c) The bottom strand is the template strand; RNA polymerase moves along this strand from 5¢ to 3¢. d) The bottom strand is the template strand; RNA polymerase moves along this strand from 3¢ to 5¢.

a) a) The top strand is the template strand; RNA polymerase moves along this strand from 5¢ to 3¢

It must be remembered that the general transcription factors and RNA polymerase are not sufficient to initiate transcription in the cell and are affected by proteins bound thousands of nucleotides away from the promoter.Proteins that link the distantly bound gene regulatory proteins to RNA polymerase and the general transcription factors include the large complex of proteins called the ________. a) activator b) terminator c) Mediator d) enhancer

c) mediator

You have a piece of DNA that includes the following sequence: 5'-ATAGGCATTCGATCCGGATAGCAT-3' 3'-TATCCGTAAGCTAGGCCTATCGTA-5' Which of the following RNA molecules could be transcribed from this piece of DNA? a. 5'-UAUCCGUAAGCUAGGCCUAUGCUA-3' b. None of the answers given is correct c. 5'-UACGAUAGGCCUAGCUUACGGAUA-3' d. 5'-AUAGGCAUUCGAUCCGGAUAGCAU-3'

d. 5'-AUAGGCAUUCGAUCCGGAUAGCAU-3'

Which one of the following is the main reason that a typical eukaryotic gene is able to respond to a far greater variety of regulatory signals than a typical prokaryotic gene or operon? a) Eukaryotes have three types of RNA polymerase. b) Eukaryotic RNA polymerases require general transcription factors. c) The transcription of a eukaryotic gene can be influenced by proteins that bind far from the promoter. d) Prokaryotic genes are packaged into nucleosomes

the transcription of a eukaryotic gene can be influenced by proteins that bind far from the promoter

In eukaryotic cells, general transcription factors are required for the activity of all promoters transcribed by RNA polymerase II. The assembly of the general transcription factors begins with the binding of the factor __________________ to DNA, causing a marked local distortion in the DNA. This factor binds at the DNA sequence called the __________________ box, which is typically located 25 nucleotides upstream from the transcription start site. Once RNA polymerase II has been brought to the promoter DNA, it must be released to begin making transcripts. This release process is facilitated by the addition of phosphate groups to the tail of RNA polymerase by the factor a) TFIIA, open reading frame b) TFIID, TATA box c) TFIIH, ori d) Sigma, lac

TFIID , tata