Which of the following is NOT a major purine or pyrimidine base found in DNA and RNA?
Explanation
This question tests the ability to distinguish between the five major nitrogenous bases (A, G, C, T, U) and the minor bases that can also be found in nucleic acids, such as hypoxanthine.
Other questions
What are the three characteristic components of a nucleotide?
What is a molecule without a phosphate group, consisting of a nitrogenous base and a pentose, called?
In pyrimidines and purines, how are the carbon and nitrogen atoms conventionally numbered?
What is the key difference that defines a nucleic acid as DNA versus RNA?
How are successive nucleotides in both DNA and RNA covalently linked?
According to the Watson-Crick model, how many base pairs are there per helical turn in B-form DNA in aqueous solution?
What are the two primary forces that hold the DNA double helix together?
What is the structural characteristic of A-form DNA compared to B-form DNA?
What is a common feature of DNA sequences that can form hairpin or cruciform structures?
What is the term for the phenomenon where the absorption of UV light by a double-stranded nucleic acid increases upon denaturation?
What is the most important source of mutagenic alterations in DNA under normal physiological conditions?
What is the primary role of ATP in cellular metabolism?
What is the molar extinction coefficient at 260 nm for GMP at pH 7.0?
What is the term for a short nucleic acid polymer containing 50 or fewer nucleotides?
The chemical synthesis of DNA via the phosphoramidite method proceeds in which direction?
What is the consequence of the slow deamination of cytosine to uracil in DNA?
Which of the following enzymes uses S-adenosylmethionine as a methyl group donor for DNA methylation?
What is the approximate distance between vertically stacked bases inside the B-form DNA double helix?
Which of the following is a regulatory nucleotide that is produced in bacteria in response to amino acid starvation?
What is the consequence of forming a cyclobutane pyrimidine dimer in a DNA strand, as induced by UV light?
Which enzyme is responsible for linking a DNA fragment to a cloning vector?
In the Sanger dideoxy sequencing method, what is the role of a dideoxynucleoside triphosphate (ddNTP)?
Which of the following enzyme cofactors contains an adenosine moiety but does not participate directly in the cofactor's primary function?
What is the structural basis for Chargaff's rule that in any cellular DNA, the number of adenosine residues equals the number of thymidine residues (A = T)?
What type of RNA serves as an adapter molecule that translates the information in mRNA into a specific sequence of amino acids?
Which of the following is the most common form of DNA found under physiological conditions?
In a sample of DNA from an unknown bacterium, adenine makes up 32 percent of the total bases. What is the percentage of guanine?
What is the primary role of the enzyme reverse transcriptase in biotechnology applications like RT-PCR?
In Z-form DNA, what conformation do the purine residues typically adopt?
Why are the carbon numbers of the pentose ring in a nucleotide given a prime (') designation?
What is the typical result of RNA hydrolysis under alkaline conditions?
What type of damage does ionizing radiation such as x-rays and gamma rays typically cause to DNA?
What is the biological function of the Dam methylase in E. coli?
Which of the following is NOT a component of coenzyme A (CoA)?
What type of chemical bond links the base to the pentose in a nucleotide?
What are the common pyrimidine bases found in RNA?
The G tetraplex structure is formed most readily by DNA sequences with a very high proportion of which residue?
What is the effect of base-stacking interactions on the stability of the DNA double helix?
Which chemical agent is commonly used to cause selective removal of purine bases from DNA, resulting in an apurinic acid?
What is the primary function of messenger RNA (mRNA)?
What does a melting point (tm) of a DNA molecule, determined under fixed pH and ionic strength, allow one to estimate?
How many hydrogen bonds are formed between a guanine (G) and cytosine (C) base pair?
What is the typical conformation of a paired, double-stranded RNA helix?
In DNA, the two polynucleotide chains are oriented in which direction relative to each other?
What type of damage is typically caused by exposing DNA to near-UV radiation?
In the Sanger sequencing method, fragments are separated by electrophoresis based on what property?
What is the role of a primer in the DNA sequencing reaction catalyzed by DNA polymerase?
What is the primary characteristic of the backbone of both DNA and RNA?
What are the structural units of DNA called when they are in their free form, such as dAMP?