DNA

13.3 DNA Replication

Copying the Code

• DNA is double-stranded

• Semiconservative with replicated

• 1 New (pink) and 1 Original (blue)

• Just need 1 strand to get the other

• A always w/ T and C always w/ G

Replication Enzymes

• Helicase=Splits the Bases

• Primase=Start point to copy

• DNA Polyermase=Connects bases

• Ligase=Glues lagging DNA

• Telomerase=Adds telomeres to ends of the DNA strands

Multiple Choice

What is the LAST step of the completion of DNA replication?

• Telomeres are added to ends of DNA

• Ligase glues Okazaki fragments

• DNA polymerase proofreads

• Topoisomerase relieves supercoiling

Multiple Choice

This enzyme synthesizes short RNA sequences to guide DNA Polymerase

• Primers

• DNA Primase

• DNA Polymerase

• Topoisomerase

Multiple Choice

This enzyme is responsible for creating telomeres added to the ends of DNA

• Topoisomerase

• Telomerase

• DNA Helicase

• DNA Primase

Multiple Choice

Why is it crucial that living things are able to replicate their DNA?

• Each cell must have its own DNA
• Less copies of DNA are needed when a new cell is created
• A cell needs multiple copies of DNA
• Only muscle cells need DNA 

Multiple Choice

Which enzyme seals okazaki fragments together on the lagging strand?

• Topoisomerase
• Helicase
• Polymerase
• Ligase

Multiple Choice

What is the purpose of DNA replication?

• Cut the DNA 
• Make more cells
• Apoptosis
• Duplicate the DNA

Multiple Choice

What is the shape of DNA?

• Double helix
• Triple helix
• Flat, bilayer
• Three-pronged rigid ladder

Multiple Choice

Nitrogenous bases are joined by which type of bond?

• polar bonds
• ionic bonds
• covalent bonds
• hydrogen bonds

Multiple Choice

Adenine bonds with ______________.

• Guanine
• Thymine
• Cytosine
• Adenine

Multiple Choice

Based on the diagram, the enzyme (represented in gray) is most likely...

• DNA polymerase
• DNA Ligase
• Nuclease
• Helicase

Multiple Choice

Which sequence of DNA bases would pair with this partial strand
CAT TCA CTG

• ATG TGA CAG
• TAC ACT GTC
• GTA AGT GAC
• CAT TCA CTG

Multiple Choice

Which enzyme is responsible for adding nucleotides?

• Topoisomerase
• DNA Polymerase
• Ligase
• Primase

Multiple Choice

What is the backbone of DNA made of?

• Nitrogen bases
• Amino acids
• Double H
• Sugar & Phosphate

Multiple Choice

This enzyme is capable of breaking Hydrogen bonds found between the bases of DNA

• Topoisomerase

• DNA Helicase

• DNA Polymerase

• Exonuclease

Multiple Choice

This enzyme is capable of breaking Hydrogen bonds found between the bases of DNA

• Topoisomerase

• DNA Helicase

• DNA Polymerase

• Exonuclease

Prokaryotic DNA Replication

• Simple Interphase S Phase

• One starting point

• Copies in both directions

• Produces 2 circular chromosomes

Eukaryotic DNA Replication

• Replicates in Interphase S phase

• Many starting points in your 46 strands of DNA (23Mom/23Dad)

• Copies in both directions until the entire chromosome is copied while enzymes check for errors

• Chromosomes don't condense until Mitosis Prophase

• Large amount of DNA=Complex

Multiple Choice

Where is the DNA found in a eukaryotic cell? 

• floating around in the cytoplasm 
• in the nucleus 

Multiple Choice

DNA is found in the nucleus

• Prokaryote
• Eukaryote

Multiple Choice

DNA is a single strand and circular in shape

• Prokaryote
• Eukaryote

Multiple Choice

DNA is free floating, not in a nucleus

• Prokaryote
• Eukaryote

Multiple Choice

When in the Cell Cycle does DNA Replication occur?

• S phase

• M phase

• Mitosis

• Interphase

• Cytokinesis

Multiple Choice

When in the Cell Cycle does DNA Replication occur?

• S phase

• M phase

• Mitosis

• Interphase

• Cytokinesis

Multiple Choice

In rapidly dividing cells, telomerase helps to prevent genes near the ends of chromosomes from being ______ or _____during replication.

• damaged or lost

• copied or replicated

• copied or lost

• copied or damaged

Multiple Choice

Telomerase adds short, repeated DNA sequences to ____ as the chromosomes are replicated.

• telomeres

• chromeres

• protermeres

• eukaremeres

Multiple Choice

Because the ends of a DNA molecule are difficult to replicate, cells use a special enzyme, called ____, to do the job.

• telomerase

• colomerase

• beoemerase

• polymerase

Multiple Choice

The tips of eukaryotic chromosomes are known as ____

• telomeres

• solomeres

• polymeres

• trimeres

Multiple Choice

During DNA replication, the DNA molecule produces ___ new complementary strands.

• two

• one

• four

• countless

Multiple Choice

The principal enzyme involved in DNA replication is called _____

• DNA polymerase

• DNA replicator

• DNA telomere

• DNA solution

Multiple Choice

DNA replication is carried out during the S phase of the cell cycle by a series of ____

• enzymes

• molecules

• pseudocells

• polymemes

Multiple Choice

DNA replication is _____, which means that each DNA molecule resulting from replication has one of the two original strands and one new strand.

• semiconservative

• conservative

• expansive

• cohorting

Multiple Choice

During replication, each strand of the double helix of DNA serves as a ____ for the new strand.

• template

• cohort

• energy source

• axis

Multiple Choice

During replication, the two strands of each DNA molecule ____.

• separate

• join together

• chemically change

• physically change

Multiple Choice

Before a cell divides, it duplicates its DNA in a copying process called replication during the ___ phase of the cell cycle.

• S

• C

• P

• K

Multiple Choice

Because each strand can be used to make the other strand, the strands are said to be ______.

• complimentary

• supplementary

• equal

• twin

Multiple Choice

Before a cell divides, its DNA must first ____

• be copied.

• be joined.

• be completed.

• be isolated.

Multiple Choice

Before a cell divides, its DNA must first ____

• be copied.

• be joined.

• be completed.

• be isolated.

Eukaryotic Replication

• DNA only copies in 5'-3' direction

• Leading Strand-Continuously follows the helicase enzyme in the 5'-3' direction (longer strand)

• Lagging Strand-Copies in the opposite direction of leading strand but still in 5'-3' direction (many short strands)

• Okazaki Fragments-Short segments of lagging DNA

Telomeres

• Protects the ends of DNA strand

• Short repeating segments of DNA that code for nothing meant to protect the real DNA code

• Prevents gene loss or damage