Quiz 2

Question 1

Consider what you know about DNA replication and select the correct statement(s) below:

a.) The lagging strand is the DNA that comprises Okazaki Fragments that are newly synthesized.
b.) Lipids are a category of macromolecules not involved in DNA replication (enzymes, templates, monomers, macromolecules).
c.) Replication occurs by a conservative mechanism where two parent strands serve as a template for the synthesis of two nascent strands. After replication, the parent strands anneal back together.
d.) Commences at promoter regions where the replication machinery, including DNA polymerase, assembles after RNA polymerase synthesizes a short, complementary RNA “primer.”
e.) All of the above are false.

Answer 1

a, b

Question 2

Suppose that the coding region of a gene contains 1,800 base pairs, with 570 in exon 1, 440 in exon 2, and 810 in exon 3 (not counting the stop codon). The post-transcriptionally-modified mRNA of the splice variant in which exon 2 was spliced out would be composed of _______ base pairs.

a.) 1230
b.) 1360
c.) 990
d.) more info required

Answer 2

1360

Question 3

A double stranded DNA from part of a chromosome

Top (5’ to 3’)
Bottom (3’ to 5’)

What strands could act as template strands for RNA transcription?

Answer 3

The Bottom Strand

Question 4

Given your knowledge of DNA replication and RNA transcription, what below is UNTRUE?

a.) DNA and RNA polymerase both read the template DNA in a 3’–>5’ direction, and synthesize the new, growing polynucleotide 5’–>3’
b.) DNA polymerase III requires double stranded nucleic acid in order to bind to, and initiate DNA replication.
c.) Primase is required for DNA and RNA polymerase to bind to the DNA backbone during replication and transcription, respectively.
d.) All of the above are true.

Answer 4

c.) Primase is required for DNA and RNA polymerase to bind to the DNA backbone during replication and transcription, respectively.

• Only required for DNA polymerase
  -> RNA polymerase does not need primer to initiate nucleic acid synthesis

Question 5

Which aspect of the 1928 Griffith experiment contributed most significantly to the understanding of bacterial genetics?

a.) The distinction between the S and R strains of Streptococcus pneumoniae.
b.) The use of heat to kill bacteria.
c.) The observation that uptake of extracellular genetic material can occur in bacteria, a process called transformation.
d.) The identification of the polysaccharide capsule in virulent bacteria that relates to pathogenicity.

Answer 5

c.) The observation that uptake of extracellular genetic material can occur in bacteria, a process called transformation.