Historical Origins
These scientists demonstrated that the "transforming principle" was destroyed by DNA-digesting enzymes, but not by protein or RNA-digesting enzymes.
A) Who are Hershey and Chase?
B) Who are Avery, MacLeod, and McCarty?
C) Who are Watson and Crick?
D) Who are Meselson and Stahl?
B) Who are Avery, MacLeod, and McCarty?
This repeating structure provides structural support and stability to the DNA molecule and is composed of sugar and phosphate units.
A) What are nitrogenous bases?
B) What are hydrogen bonds?
C) What is the sugar-phosphate backbone?
D) What is a nucleosome?
C) What is the sugar-phosphate backbone?
This enzyme uses energy from ATP to unwind the DNA double helix, creating single-stranded templates for replication.
A) What is DNA ligase?
B) What is DNA primase?
C) What is DNA helicase?
D) What is DNA polymerase III?
C) What is DNA helicase?
This mechanism of replication, proven by Meselson and Stahl, results in two DNA molecules that each contain one original parent strand and one new strand.
A) What is conservative replication?
B) What is dispersive replication?
C) What is semiconservative replication?
D) What is progressive replication?
C) What is semiconservative replication?
These specialized short repeated DNA sequences protect the ends of linear chromosomes from deterioration and fusion with other chromosomes.
A) What are centromeres?
B) What are exons?
C) What are telomeres?
D) What are introns?
C) What are telomeres?
This 1952 experiment used radioactive isotopes (32P and 35S) to prove that DNA is the molecule used to reprogram bacterial cells during viral infection.
A) What is the Griffith experiment?
B) What is the Avery experiment?
C) What is the Hershey-Chase experiment?
D) What is the Meselson-Stahl experiment?
C) What is the Hershey-Chase experiment?
A single DNA nucleotide is composed of these three fundamental components.
A) What are a nitrogenous base, a ribose sugar, and a fatty acid?
B) What are an amino acid, a pentose sugar, and a phosphate group?
C) What are a phosphate group, a deoxyribose sugar, and a nitrogenous base?
D) What are adenine, thymine, and a phosphodiester bond?
C) What are a phosphate group, a deoxyribose sugar, and a nitrogenous base?
Because DNA polymerase cannot start a strand from scratch, this enzyme must first synthesize a short RNA primer.
A) What is DNA helicase?
B) What is DNA primase?
C) What is DNA polymerase I?
D) What is DNA gyrase?
B) What is DNA primase?
Regardless of whether it is the leading or lagging strand, DNA synthesis always proceeds in this specific chemical direction.
A) What is 3' to 5'?
B) What is 5' to 3'?
C) What is right to left?
D) What is left to right?
B) What is 5' to 3'?
This enzyme extends telomeres using an internal RNA template, which prevents chromosome shortening in certain cells like stem cells and cancer cells.
A) What is DNA polymerase III?
B) What is telomerase?
C) What is DNA ligase?
D) What is photolyase?
B) What is telomerase?
This researcher determined that in any given DNA molecule, the amount of Adenine always equals Thymine, and the amount of Cytosine always equals Guanine.
A) Who is Rosalind Franklin?
B) Who is Erwin Chargaff?
C) Who is Francis Crick?
D) Who is Bijal Karia?
B) Who is Erwin Chargaff?
While A-T pairs are held together by two hydrogen bonds, these two nitrogenous bases are more stable because they are held together by three.
A) What are adenine and thymine?
B) What are adenine and cytosine?
C) What are thymine and uracil?
D) What are cytosine and guanine?
D) What are cytosine and guanine?
Known as the main replicative enzyme in E. coli, it adds new nucleotides to the free 3' end of the growing DNA chain.
A) What is DNA polymerase I?
B) What is DNA polymerase II?
C) What is DNA polymerase III?
D) What is DNA primase?
C) What is DNA polymerase III?
This Y-shaped structure is formed where the two original DNA strands separate, enabling the synthesis of new strands.
A) What is a replicon?
B) What is an origin of replication?
C) What is a replication fork?
D) What is a chiasma?
C) What is a replication fork?
This specific repair mechanism fixes thymine dimers caused by UV light by using light energy to cleave the covalent linkage between bases.
A) What is excision repair?
B) What is mismatch repair?
C) What is photorepair?
D) What is proofreading?
C) What is photorepair?
Using Maurice Wilkins' DNA fibers, she performed X-ray diffraction studies to discover that the DNA molecule is helical.
A) Who is Martha Chase?
B) Who is Rosalind Franklin?
C) Who is Oswald Avery?
D) Who is Bijal Karia?
B) Who is Rosalind Franklin?
This covalent bond links the 5' phosphate group of one nucleotide to the 3' —OH of the next, forming the backbone of the DNA strand.
A) What is a hydrogen bond?
B) What is a peptide bond?
C) What is a phosphodiester bond?
D) What is an ionic bond?
C) What is a phosphodiester bond?
This enzyme is responsible for removing RNA primers from the lagging strand and filling the resulting gaps with DNA nucleotides.
A) What is DNA polymerase III?
B) What is DNA polymerase I?
C) What is DNA ligase?
D) What is telomerase?
B) What is DNA polymerase I?
These short DNA segments are synthesized discontinuously on the lagging strand in the direction away from the replication fork.
A) What are replicon fragments?
B) What are Okazaki fragments?
C) What are Chargaff's fragments?
D) What are Klenow fragments?
B) What are Okazaki fragments?
In this nonspecific repair process, a damaged section of DNA is recognized by the UvrABC complex, removed, and replaced by DNA polymerase.
A) What is photorepair?
B) What is mismatch repair?
C) What is excision repair?
D) What is replication?
C) What is excision repair?
These two researchers proposed the double helix model of DNA in 1953, despite not performing a single DNA-related experiment themselves.
A) Who are James Watson and Francis Crick?
B) Who are Avery and MacLeod?
C) Who are Hershey and Chase?
D) Who are Meselson and Stahl?
A) Who are James Watson and Francis Crick?
This term describes the orientation of the two strands of a DNA molecule, which run in opposite chemical directions to one another.
A) What is complementary?
B) What is semiconservative?
C) What are antiparallel strands?
D) What is bidirectional replication?
C) What are antiparallel strands?
This specific topoisomerase relieves the torsional strain (torque) generated ahead of the replication fork during the unwinding of DNA.
A) What is DNA helicase?
B) What is DNA ligase?
C) What is DNA polymerase I?
D) What is DNA gyrase?
D) What is DNA gyrase?
This macromolecular assembly coordinates the multiple enzymes involved in replication, allowing both strands to be synthesized simultaneously.
A) What is the ribosome?
B) What is the nucleosome?
C) What is the replisome?
D) What is the centrosome?
C) What is the replisome?
A deficiency in this enzyme would result in the failure of preformed DNA fragments (like Okazaki fragments) to link into a single continuous strand.
A) What is DNA helicase?
B) What is DNA primase?
C) What is DNA polymerase III?
D) What is DNA ligase?
D) What is DNA ligase?