Amoeba Sisters: DNA Replication Quiz

Questions and Answers

Why does DNA need to replicate before cells divide?

So that each cell has a full copy of DNA

Total number of deoxyribose (sugar) in the image?

Total number of nitrogenous bases in the image?

Total number of hydrogen bonds in the image?

3 Signup and view all the answers

What is phosphate depicted as in the DNA diagram?

A green circle Signup and view all the answers

What is helicase?

Enzyme that unzips the double-stranded DNA by breaking the hydrogen bonds holding the bases together Signup and view all the answers

What is DNA polymerase?

Enzyme that builds a new DNA molecule by adding complementary strands of DNA to the original, unzipped DNA molecule Signup and view all the answers

What is primase?

Enzyme that synthesizes a primer so DNA polymerase knows where to begin working Signup and view all the answers

What is ligase?

Enzyme that binds or 'glues' fragments of DNA together Signup and view all the answers

What does helicase do in the DNA replication process?

Unwinds or unzips DNA strands Signup and view all the answers

What does primase tell polymerase?

Where to start Signup and view all the answers

What does polymerase do in DNA replication?

Builds new DNA using the original DNA strand Signup and view all the answers

What does ligase do with the fragments of DNA?

Binds or 'glues' fragments of new DNA to old DNA Signup and view all the answers

Explain what is meant by the 'lagging' strand and why this occurs.

It replicates at a slower pace because it is being replicated in the opposite direction of the replication fork. Signup and view all the answers

Study Notes

DNA Replication Overview

DNA replication ensures that each new cell receives a complete set of genetic information.
Before cell division, replication provides a full copy of DNA to daughter cells.

Key Components of DNA

Deoxyribose Sugar: Essential sugar in DNA, appears 6 times in the provided diagram.
Nitrogenous Bases: Fundamental components of DNA, also represented 6 times in the diagram.
Phosphate Groups: Illustrated as green circles in DNA structures, linking the sugar molecules.

DNA Replication Enzymes

Helicase:
- Enzyme responsible for unwinding the double-stranded DNA.
- Breaks hydrogen bonds between nitrogenous bases to separate strands.
DNA Polymerase:
- Synthesizes new DNA strands by adding complementary bases to the original DNA strand.
Primase:
- Creates an RNA primer that signals DNA polymerase where to initiate synthesis of new DNA.
Ligase:
- Joins DNA fragments together, sealing gaps between newly synthesized strands.

DNA Replication Steps

Helicase unzips the two strands of DNA to prepare for replication.
Primase lays down primers to guide the starting point for DNA polymerase.
DNA polymerase constructs new DNA strands by utilizing the original template.
Ligase connects any broken pieces of DNA, ensuring a continuous strand.

Lagging Strand

The lagging strand is synthesized more slowly as it replicates in the opposite direction of the replication fork.
This strand requires multiple primers and is built in short fragments, resulting in more complex replication.

Description

Test your understanding of DNA replication with this quiz based on the Amoeba Sisters video recap. Answer questions related to the components of DNA and its replication process. Perfect for biology students looking to reinforce their knowledge of genetics.