DNA Replication IB Bio (vision learning)

Why are triphosphate nucleotides required for DNA synthesis?

• Each phosphate contributes energy and a total of three are needed for each step.

• The bridge between each nucleotide must be three phosphates long.

• The breaking of the high-energy bond between the 2nd and 3rd phosphates provides the energy for DNA synthesis.

• Only triphosphate nucleotides fit into both DNA helicase and Okazaki fragments.

Select the comparison that is accurate.

• DNA helicase is like a word processor.

• Nucleotide triphosphates are like wrecking balls.

• DNA polymerase is like a copy machine.

• Phosphate bonds are like building blocks.

Study the table shown below. Identify the sequence of discoveries that occurs in the correct order.

• A

• B

• C

• D

Which of the following could NOT have been discovered if the Kornberg team had not first identified the primer responsible for starting DNA synthesis?

• Nucleotides occur in complementary base-pairs.

• DNA synthesis is semi-conserative.

• Replication begins at specific origins.

• DNA synthesis is unidirectional.

In the late 1970s, two research groups independently discovered what was responsible for separating the two strands of a DNA helix within a cell. The mechanism was identified as

• an enzyme called DNA ligase.

• an enzyme called DNA polymerase.

• an enzyme called DNA helicase.

• nucleotide triphosphates.

Which statement below BEST explains why biochemists often use in vitro reconstitution as a research method?

• It allows them to recreate a cellular event in isolation and manipulate it as necessary.

• It allows them to recreate and observe a cellular event in a natural environment

• It allows them to recreate and observe a reproductive event within the human body.

• It allows them to recreate a biochemical event using only synthetic materials.

A human body contains between 10 and 100 trillion cells. Each cell within a body contains the same DNA sequence (except on rare occasions). The reason each DNA sequence is identical is because

• the triphosphate nucleotides are the same in all cells.

• new DNA strands are made only by copying pre-existing DNA strands.

• there is only one pattern a DNA sequence can follow.

• there are only four nucleotides that make up a DNA sequence.

Inside a cell, the primers that are necessary for DNA polymerase to start working are made of

• RNA

• DNA Primer

• lagging strands.

• Okazaki fragments.

Based on the diagram, how many origins of replication are represented?

• 1
• 2
• 3
• 4

Tags

NGSS.HS-LS3-2

The picture below shows the steps of DNA replication beginning with step one and ending with step three.

​Because you are reusing the old, or parent, DNA strand DNA replication is said to be

• Semi- Conservative

• Semi-discontinuous

• Continuous

• Fully-Conserveative