Indicate the answer choice that best completes the statement or answers the q or
ID: 99979 • Letter: I
Question
Indicate the answer choice that best completes the statement or answers the q or answers the question Exhibit 10A Consider the following diagrams showing a replication fork moving from left to right. The thick lines represent the template/parental strands. The 5 and 3 represent the ends of those template/parental strands 5" 3" 3' 1. Refer to Exhibit 10A. Which Okazaki fragment was synthesized earliest? a. A b. B d. D 2. The energetic driving force for nucleic acid synthesis is a. removal of pyrophosphate from the incoming nucleotide. b. removal of pyrophosphate from the growing strand c. removal of inorganic phosphate from the incoming nucleotide. d. removal of inorganic phosphate from the growing strand. 3. DNA polymerase III from E. coli a. is a large, multisubunit protein b. has a sliding clamp portion that anchors it to DNA c. has a polymerization site separate from the DNA binding site d. all of theseExplanation / Answer
1c.Okazaki fragments are short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication.
2.b.Removal of pyrophosphate from growing nucleotide chain.
3a.DNA polymerase 3 is a multisubunit enzyme each comprising , and subunits.
4.b.Ligating the final product is the function of ligases.
5c.Histone biosynthesis takes place only in eukaryotes.
6.True as DNA polymerases share the same functions in both the prokaryotes and eukaryotes but these are not identical.
8.b.The length of Okazaki fragments in the lagging strand is about 100-200 nucleotidesin eukaryotes and about 1000-2000 nucleotides in prokaryotes.
9.a.DNA - RNA - Protein; replication- transcription - translation
10.b.Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA (especially mRNA) by the enzyme RNA polymerase.
11.d.All these challenges are accepted by the cell and cell adopts mechanisms to overcome it by either forming okazaki fragments or the lagging starnds or helicases which separate two DNA strands.
12.d.Density gradient centrifugation was used.
13.b.Unwinding of DNA duplex is the first step required for the new DNA synthesis.
14.True- Mismatch repair requires both the strands.
16.d Mismatch repair can repair a single nucletide which is mismatched.
17.c.In DNA, uracil is readily produced by chemical degradation of cytosine, so having thymine as the normal base makes detection and repair of such incipient mutations more efficient.
18.d.3'5' (reverse) exonuclease activity mediates proofreading.
20c.Holliday described a mechanism of DNA-strand exchange that attempted to explain gene-conversion events that occur during meiosis in fungi.