Which of the following are classified as pyrimidines?
thymine and cytosine
What type of bond is formed between the hydroxyl group of one nucleotide and the phosphate group of an adjacent nucleotide, forming the sugar-phosphate backbone of DNA?
phosphodiester bond
What types of bonds are formed between complementary DNA bases?
hydrogen bonds
Based on the following replication bubble, which of these statements is true?
W and Y are leading strands, X and Z are lagging strands
In E. coli, replication begins at which chromosome site?
oriC
What is the DNA replication fork?
It is the site where the DNA helix opens to two single DNA strands.
Okazaki fragments form on the lagging strand during DNA replication.
True
DNA replication in eukaryotes
initiates at multiple origins
DNA replication proceeds
semiconservatively
DNA replication occurs by adding
dNTPs to the 3′ end of the daughter strand
What are two distinguishing features of RNA?
RNA has a ribose sugar and uracil nitrogenous base.
What is the role of a promoter region of a gene?
Recruit transcription factors that form the initiation complex.
Which region(s) of a gene are not found within the mRNA transcript?
promoter and termination region
ou want to design a drug that prevents transcription of eukaryotic mRNAs but does not affect transcription of other RNAs. What enzyme would you target?
RNA polymerase II
Which of the following is part of a DNA molecule?
Promoter
Which enzyme is required to initiate 5′ capping of eukaryotic mRNA transcripts by removing the terminal phosphate group?
guanylyl transferase
Which of the following bacterial RNA polymerase subunits is found in the holoenzyme, but not the core enzyme?
σ (sigma)
What is the general name for the components of the spliceosome, which removes introns from mRNAs?
small nuclear ribonucleoproteins
What are catalytically active RNAs that can activate processes such as self-splicing?
ribozymes
What is the purpose of alternative splicing in eukaryotic cells?
Produce multiple polypeptide sequences from a single primary transcript.