Drama 🎭
Question: This scientist, along with James Watson, proposed the 3D model of the DNA double helix in 1953. Options:
A) Linus Pauling
B) Maurice Wilkins
C) Francis Crick
D) Frederick Sanger
Answer: C) Francis Crick
Question: If one strand of DNA reads "A-T-T-G-C," what would the sequence of its complementary strand be? Options:
A) T-C-C-A-T
B) T-A-A-C-G
C) C-G-G-T-A
D) U-A-A-C-G
Answer: B) T-A-A-C-G
Question: In a classic crime scene drama, what is the term for the unique pattern of DNA fragments used to identify a person, often seen as a series of bars on an X-ray film?
Options:
A) A chromatogram
B) An autoradiogram
C) A karyotype
D) A DNA fingerprint
Answer: D) A DNA fingerprint
During the process of DNA denaturation (melting), the double helix separates into single strands. This transition is typically monitored by measuring the "Hyperchromic Shift." What exactly happens to the DNA sample during this shift?
A) The solution becomes more viscous.
B) The absorbance of UV light at 260 nm increases.
C) The DNA begins to emit visible blue light.
D) The phosphodiester backbone is chemically hydrolyzed.
B (Absorbance increases because unstacked bases absorb more light).
Question: The crucial X-ray diffraction image "Photo 51" was taken by this scientist, whose work was critical evidence for the helical structure Options:
A) Maurice Wilkins
B) Rosalind Franklin
C) Erwin Chargaff
D) Raymond Gosling
Answer: B) Rosalind Franklin
Question: What is the fundamental repeating unit of eukaryotic chromatin, consisting of DNA wrapped around histones? Options:
A) Nucleosome
B) Replisome
C) Ribosome
D) Centrosome
Answer: A) Nucleosome
Question: When DNA is denatured by heat, its UV light absorption at 260 nm increases. This physical phenomenon is known as:
Options:
A) The Bohr Effect
B) Hyperchromicity
C) Fluorescence
D) Quenching
Answer: B) Hyperchromicity
JACPOTTTTTTT (free points - 167p)
167p
Question: The Hershey-Chase "blender" experiment used which radioactive isotope to specifically label DNA? Options:
A) ¹⁴C (Carbon-14)
B) ³⁵S (Sulfur-35)
C) ³²P (Phosphorus-32)
D) ¹⁵N (Nitrogen-15)
Answer: C) ³²P (Phosphorus-32)
Question: Which enzyme is responsible for "unzipping" the DNA double helix at the replication fork? Options:
A) DNA Polymerase
B) Helicase
C) Primase
D) Ligase
Answer: B) Helicase
Question: You have a sample with a mixture of DNA, RNA, and proteins. To study the DNA, you need to purify it. Which of the following steps is typical in a DNA purification protocol?
Options:
A) Adding dideoxynucleotides to stop synthesis
B) Using phenol-chloroform to separate proteins from nucleic acids
C) Running the sample on an agarose gel
D) Exposing the sample to X-rays
Answer: B) Using phenol-chloroform to separate proteins from nucleic acids 🎰🎰🎰
In the Kornberg model of DNA replication, the synthesis of Okazaki fragments on the lagging strand creates a series of nicks. Which enzyme is responsible for catalyzing the formation of the final phosphodiester bond to "seal" these nicks?
A) DNA Polymerase III
B) DNA Primase
C) DNA Ligase
D) Topoisomerase
C (Ligase uses ATP or NAD+ to join the 3'-OH and 5'-phosphate).
Question: In the Meselson-Stahl experiment, what was the distribution of DNA bands after two rounds of replication in a ¹⁴N medium? Options:
A) One heavy band, one light band
B) One intermediate (hybrid) band only
C) One intermediate band, one light band
D) One heavy band, one intermediate band
Answer: C) One intermediate band, one light band
Question: Which of the following is a characteristic of "heterochromatin" as opposed to "euchromatin"?Options:
A) It is loosely packed
B) It is transcriptionally active
C) It remains highly condensed throughout the cell cycle
D) It is rich in gene sequences
Answer: C) It remains highly condensed throughout the cell cycle
In Maxam-Gilbert sequencing, which hazardous chemical is used specifically to modify and cleave the DNA at Guanine (G) residues?
A) Hydrazine
B) Dimethyl sulfate (DMS)
C) Piperidine
D) Formic acid
B) Dimethyl sulfate (DMS) 🤑🤑🤑
According to W.A. Bickmore’s Chromosome Structural Analysis, the 10 nm fiber represents the first level of DNA compaction. When this fiber further coils into the 30 nm fiber (the solenoid or zigzag model), which specific component is essential for stabilizing this higher-order structure?
A) The H1 "linker" histone
B) Non-histone chromosomal proteins (NHCs)
C) Telomerase RNA
D) The RNA Polymerase II complex
A (Histone H1 pulls nucleosomes together to facilitate the 30 nm compaction).
Question: In the late 1800s, this Swiss physician isolated a substance from the nuclei of white blood cells that he called "nuclein," which we now know as DNA. Options:
A) Albrecht Kossel
B) Friedrich Miescher
C) Phoebus Levene
D) Thomas Hunt Morgan
Answer: B) Friedrich Miescher
Question: The "Kornberg enzyme" (DNA Polymerase I) is unique in E. coli because it possesses which specific enzymatic activity required for removing RNA primers? Options:
A) 3' → 5' exonuclease
B) 5' → 3' exonuclease
C) 5' → 3' endonuclease
D) 3' → 5' polymerase
Answer: B) 5' → 3' exonuclease
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THIS ONE IS EASYYYYYY
Question: The Sanger method of DNA sequencing relies on the inclusion of which specific molecule to terminate chain elongation?
Options:
A) dNTPs
B) ddNTPs
C) RNA Primers
D) Formamide
Answer: B) ddNTPs
In the Maxam-Gilbert chemical degradation method, different reagents are used to modify specific bases. According to the protocols outlined in Brown’s Genomes 3, which reagent (in the presence of high salt) is used to specifically target and cleave only at Cytosine (C) residues?
A) Dimethyl sulfate (DMS)
B) Formic acid
C) Piperidine
D) Hydrazine
D (Hydrazine alone reacts with C+T; adding 1.5 M NaCl suppresses the T reaction, making it C-specific).