Question

biology exam 7
for questions 1 - 3, identify the function of each enzyme in dna replication.
(more than one option will be used)

1. helicase:
2. dna polymerase:
3. ligase:

a. read the dna template and assemble nucleotides.
b. connect the newly synthesized dna fragments.
c. prevent the dna from getting tangled.
d. separate the double - stranded dna into single strands.
for questions 4 - 8, match the letters to the correct component of the dna replication fork in the diagram below.

1. dna polymerase:
2. dna ligase:
3. topoisomerase:
4. leading strand:
5. lagging strand:

b.h.2: structure and function of dna in cells

1. transgenic organisms are...

a. likely to die soon after birth.
b. unlikely to have frameshift errors.
c. organisms with several mutations.
d. organisms with altered genetic code.

Explanation:

• DNA Polymerase: In DNA replication, DNA polymerase reads the DNA template and assembles nucleotides to form new DNA strands. In the diagram, the component labeled \(A\) (in the lower strand) is DNA polymerase as it is involved in the synthesis process.
• DNA Ligase: DNA ligase connects the newly - synthesized DNA fragments (Okazaki fragments in the lagging strand). In the diagram, the component labeled \(B\) is DNA ligase as it acts on the Okazaki fragments.
• Topoisomerase: Topoisomerase prevents the DNA from getting tangled by relieving the torsional stress ahead of the replication fork. In the diagram, the component labeled \(E\) is topoisomerase.
• Leading Strand: The leading strand is synthesized continuously in the \(5'\) to \(3'\) direction. In the diagram, the strand labeled \(D\) is the leading strand as it is synthesized without interruption.
• Lagging Strand: The lagging strand is synthesized discontinuously as Okazaki fragments. In the diagram, the strand labeled \(C\) is the lagging strand.

Answer:

1. \(A\)
2. \(B\)
3. \(E\)
4. \(D\)
5. \(C\)