Show:
Chargaff's Rules
Enzymes
Central Dogma
Replication
Gene to Protein
100

It is hypothesized that each DNA strand replicates

A) Dispersed 

B) Conservative

C) Hemi-conservative

D) Semiconservative

D) Semiconservative

100

Binds to single-stranded DNA to prevent DNA from rewinding back

A) Single-stranded binding proteins (SSB)

B) Topoisomerase

C) DNA Ligase

D) Sliding Clamp

A) Single-stranded binding proteins (SSB)

100

Which of the following is not a true statement comparing prokaryotic and eukaryotic DNA replication?

  1. Both eukaryotic and prokaryotic DNA polymerases build off RNA primers made by primase.
  2. Eukaryotic DNA replication requires multiple replication forks, while prokaryotic replication uses a single origin to rapidly replicate the entire genome.
  3. DNA replication always occurs in the nucleus.
  4. Eukaryotic DNA replication involves more polymerases than prokaryotic replication.


C) DNA replication always occurs in the nucleus.

100

Which of the following does the enzyme primase synthesize?

  1. DNA primer
  2. RNA primer
  3. Okazaki fragments
  4. phosphodiester linkage

B) RNA primer

100

How many nucleotides are in 12 mRNA codons?

12

24

36

48

C) 36

200

Which of the following are purines?

A) Cytosine

B) Adenine

C) Thymine

D) Guanine

B & D Adenine and Guanine

200

Unwinds the double-stranded DNA helix, separating the two strands by breaking the hydrogen bonds between base pairs

A) Primase

B) Topoisomerase

C) Helicase

D) DNA Polymerase

 

C) Helicase

200

What does the Central Dogma state about the flow of genetic information


DNA>RNA>Polypeptide

200

In which direction does DNA replication take place?

  1. 5'-3'
  2. 3'-5'
  3. 5'
  4. 3'

A) 5'-3'

200

The RNA components of ribosomes are synthesized in the ________.

  1. cytoplasm
  2. nucleus
  3. nucleolus
  4. endoplasmic reticulum

C) nucleolus

The nucleolus is a dense region within the nucleus where ribosomal RNA (rRNA) is transcribed, processed, and assembled with proteins to form the subunits of ribosomes.

These subunits are then exported to the cytoplasm, where they combine to become functional ribosomes.

300

In humans, there is approximately 30% adenine.  What is the percentage of other nitrogenous bases?

 

D) [A]=30%, [T]=30%, [G]=20%, [C]=20%

According to Chargaff's rule, Adenine (A) is paired to Thymine (T)  Cytosine (C) is paired to Guanine (G)

[A]+[G]+[C]+[T]=100%

Here [A]=30% therefore % of [T] is also 30%

Therefore [G]+[C]= 100-60 = 40%  [G]=20 and [C]=20%

300

Binds to RNA primer and adds new DNA nucleotides to the 3' end of primer

A) RNA polymerase

B) DNA Polymerase III/δ

C) DNA Ligase

D) DNA Primase


B) DNA polymerase δ (eukaryotic cells) or

DNA polymerase III (prokaryotic cells)

300

During __An RNA sequence is converted into an amino acid sequence while during __a DNA sequence is converted into an RNA sequence.

A) Translation, Transcription

B) Transcription, Translation

C) Replication, Elongation

D) Initiation, Termination

A) Translation, Transcription

300

The ends of the linear chromosomes are maintained by

  1. helicase
  2. primase
  3. DNA pol
  4. telomerase

D) Telomerase

300

The binding of ________ is required for transcription to start.

  1. a protein
  2. DNA polymerase
  3. RNA polymerase
  4. a transcription factor

C) RNA polymerase

 RNA polymerase. Transcription initiation requires the binding of RNA polymerase to a DNA sequence called a promoter, which signals where the polymerase should begin transcribing. Transcription factors can also bind to specific regions of DNA, influencing the binding of RNA polymerase

400

DNA Replication occurs during which of the following phases?

A) S Phase of Interphase

B) G2 Phase of Interphase

C) G1 Phase of Interphase

D) Prophase of Interphase

A) Occurs during S phase of interphase

400

Links Okazaki fragments together

A) RNA polymerase

B) DNA Polymerase III/δ

C) DNA Ligase

D) DNA Primase

C) DNA Ligase

400

Which of the following components is not involved during the formation of the replication fork?

  1. single-strand binding proteins
  2. helicase
  3. origin of replication
  4. ligase

D) Ligase

During the formation of the replication fork, the following components are involved:

  • Helicase: Unwinds the DNA double helix at the origin of replication, creating the replication fork.

  • Single-strand binding proteins (SSBs): Bind to the separated DNA strands to keep them from reannealing or forming secondary structures.

  • Origin of replication: The specific sequence on the DNA where replication begins—this is where the replication fork starts to form.

  • DNA ligase is not involved in the formation of the replication fork.
    Instead, it functions later in replication to seal nicks in the sugar-phosphate backbone, especially between Okazaki fragments on the lagging strand.

400

During proofreading, which of the following enzymes reads the DNA?

  1. primase
  2. topoisomerase
  3. DNA polymerase
  4. helicase

C) DNA polymerase is the enzyme responsible for building new DNA strands by reading the existing template strand, and it also has the ability to proofread its own work, checking for and correcting any errors in the newly synthesized DNA

400

Cancer causing genes are called ________.

  1. oncogenes
  2. tumor suppressor genes
  3. transformation genes
  4. mutated genes

A) oncogenes

500

DNA strands are held together by 

A) Covalent bonds

B) Peptide bonds

C) Purine-Pyrimidine bonds

D) Hydrogen bonds

D) Hydrogen bonds

500

DNA proofreading – DNA polymerase (δ or III) corrects mispairing of bases as they occur during replication.

A) Only in eukaryotes

B) In both prokaryotes and eukaryotes

C) In both prokaryotes & eukaryotes, proofreads but does not correct

D) In both but prokaryotes only proofreads and does not correct

B) In both prokaryotes and eukaryotes

500

Which event contradicts the central dogma of molecular biology?

  1. Poly-A polymerase enzymes process mRNA in the nucleus.
  2. Endonuclease enzymes splice out and repair damaged DNA.
  3. Scientists use reverse transcriptase enzymes to make DNA from RNA.
  4. Codons specifying amino acids are degenerate and universal.

C) Scientists use reverse transcriptase enzymes to make DNA from RNA.

500

The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code explains this?

  1. complementarity
  2. nonsense codons
  3. universality
  4. degeneracy

D) Degeneracy; The feature of the genetic code that explains why both AUC and AUA codons specify isoleucine is degeneracy. Degeneracy means that multiple codons can code for the same amino acid. In this case, both AUC and AUA are part of the set of codons that specify isoleucine

500

Post-translational modifications of proteins can affect which of the following?

  1. protein function
  2. transcriptional regulation
  3. chromatin modification
  4. all of the above

D) All of the above