DNA Repliction and PCR

​DNA replication and PCR

Multiple Choice

In what phase of the cell cycle does DNA replication take place?

• G1

• S

• G2

• Prophase

Multiple Choice

Which of the following units are repeatedly joined together to form a strand of DNA?

• Amino Acids

• Nucleotides

• Fatty Acids

• Polysaccharides

Multiple Choice

Nitrogen bases are joined by which type of bond?

• polar bonds

• hydrogen bonds

• phosphate bonds

• deoxyribose bonds

Multiple Choice

Adenine bonds with _____

• Cytosine

• Thymine

• Guanine

• Uracil

Multiple Choice

Cytosine bonds with ____

• Adenine

• Thymine

• Guanine

• Uracil

DNA Replication

DNA Replication

 Replication = DNA copies itself exactly

 (Occurs within the nucleus)


Any mistake in copying = mutation

 (repair mechanisms) 


DNA mutation


gene or chromosomal mutation

A. Basic Facts of DNA
Replication

1. Complementary
base pairing

makes replication

possible

C - G
A - T

A. Basic Facts of DNA
Replication

2. One side of DNA molecule is a

template

for making the other side
(strand)

B. Process of DNA
Replication

1.
Uncoil & unzip DNA molecule

 Enzyme (-ase) breaks

weak

Hydrogen Bond

between bases

B. Process of DNA
Replication

2. Enzyme brings in complementary

N-bases

DNA Replicase

B. Process of DNA
Replication

3. Insert N-bases

Replication Fork

C

-

G

A

-

T

C. Semi-conservative
replication

1.

Each new DNA

molecule

contains

one old strand

&

one new strand

Multiple Choice

Which enzyme is responsible for unwinding the DNA double helix prior to replication?

• DNA polymerase I

• DNA polymerase III

• Helicase

• Ligase

Multiple Choice

Which enzyme fixes the Okazaki fragments in the lagging strand?

• Helicase

• Polymerase

• Ligase

• Primerase

Multiple Choice

The separation of the two single strands of DNA creates a ‘Y’ shape?

• enzyme

• unzip

• A replication fork

Multiple Choice

If the percentage of DNA is made of 30% Thymine, what is the correct percentage of Guanine?

• 30
• 15
• 20
• 60

Multiple Choice

The process of DNA replication is called semi conservative because it results in

• none of these

• two DNA molecules. One original molecule and one with two new strands

• two exact copies with new strands

• two identical molecules, each with 1 original strand and one new.

Multiple Choice

Which enzyme is responsible for adding DNA nucleotides?

• Topoisomerase

• DNA polymerase III

• Ligase

• Primase

Reorder

order of replication

• 3

• 4

• 1

• 2

1

2

3

4

• 1
• 2
• 3
• 4

Read the text in your book about PCR

Write an outline how PCR takes place.

Step 1
Step2
Step3

​​https://www.nature.com/scitable/topicpage/the-biotechnology-revolution-pcr-and-the-use-553/

PCR

Multiple Choice

What is the purpose of PCR?

• To produce millions of copies of DNA.
• To produce millions of copies of a specific region of DNA
• To add nucleotides to a DNA sequence
• To watch polymerase work.

Multiple Choice

Why does PCR require a specific type of polymerase?

• Taq polymerase can withstand the range of temperatures in PCR without denaturing.
• Taq polymerase is the most inexpensive type of polymerase.
• Taq polymerase is the most common type of polymerase.
• A specific type of polymerase is unnecessary.

Multiple Choice

What is the denaturation step?

• mutating RNA polymerase

• Cooling DNA to allow primers to form

• separating DNA helix in a cold environment

• separating DNA helix with using heat

Multiple Choice

Does PCR require a primer?

• Yes

• No