Module 12 - DNA Replication

Question 1

Below is one strand from part of the amelogenin gene. What is the nucleotide sequence of the other strand?

5’-CCCTGGGCTCT-3’

A: 3′ -ACTGTTAGATT-5′
B: 3′ -GGGACCCGAGA-5′
C: 5′ -GGGACCCGAGA-3′
D: 3′ -CCCTGGGCTCT-5′
E: 5′ -CCCTGGGCTCT-3′

Answer 1

The correct answer is B because the strand has to be in the opposite direction of each other (5’ 3’ goes with 3’ 5’).

C goes with G, A goes with T.

Question 2

Two DNA Chains

Answer 2

Complementary and Antiparallel.

Question 3

Copying DNA (Replication)

Answer 3

1. DNA strands are separated.
2. Every single strand is used as a template to make a complementary strand.
3. Two identical DNA molecules are produced

Question 4

Enzymes Perform Replication

Answer 4

• Helicases unwind DNA double helix.
• Single Stranded Binding Proteins hold separated DNA strands apart.
• Primase makes a starting point (primer).
• DNA polymerase connects new complementary bases.
• Ligase attaches pieces together.

Question 5

How would DNA replication be affected if ligase were not available?

A: The template strands would not be able to separate.
B: Replication would result in many small segments of DNA instead of a complete molecule.
C: Complementary RNA would be produced but not complementary DNA.
D: The DNA strands would separate but replication would not be able to start.
E: The DNA strands produced by replication would not be complementary to the template strands.

Answer 5

The correct answer is B, there will be small sections of the DNA but not as a whole.

Question 6

You need many copies of the amelogenin gene, which you will make using Polymerase Chain Reaction (PCR). You will need to follow the steps of replication. Which of the following would allow you to begin?

A: Add short stretches of single-stranded DNA complementary to the sequence at either end of the gene.
B: Add DNA polymerase enzyme.
C: Break the covalent bonds that hold the double helix together.
D: Break the hydrogen bonds that hold the double helix together.

Answer 6

The correct answer is D because breaking the hydrogen bonds will allow the primer to get into the DNA.

The sequence goes: D - A - C

Question 7

Which of the strands of DNA could act as a primer for the DNA sequence shown below?

5’-CCCTGGGCTCTGTAAATGTTTCTAAGTG-3’
3’-GGGACCCGAGACATTTACAAAGATTCAC-5’

A: 3′ -ACTGTTAGA-5′
B: 3′ -AAATTTGGC-5′
C: 3′ -ATGCTTTGA-5′
D: 5′ -GGGACCCGA-3′
E: 5′ -CCCTGGGCT-3′

Answer 7

E is complementary to the bottom strand.

E: 5′ -CCCTGGGCT-3′

Question 8

Amelogenin gene

Answer 8

Use to determine the sex of the person. People with two amelogenin genes indicate there are both X and Y chromosomes, meaning that their sex is male.

Question 9

Short Tandem Repeat (STRs)

Answer 9

Simple sequence repeats, different people have different numbers of repeats in their chromosomes.

Question 10

What is the chance that someone might have 5 and 7 repeats for the STR THO1 just by accident?

A: 1/200
B: 1/206
C: 1/600
D: 1/1200
E: 1/2600

Answer 10

D: 1/1200

5 repeats STR THO1 has the possibilities of 1/200 and 7 repeats STR THO1 has the possibilities of 1/6.

Question 11

In his experiments using bacteria and mice, Griffith discovered that:

a. heat-killed bacteria can kill mice
b. non-pathogenic bacteria can never be made to cause disease
c. some substances from pathogenic cells could be transferred to non-pathogenic cells, making them pathogenic
d. the capsule from pathogenic bacteria could transform non-pathogenic bacteria

Answer 11

c. some substances from pathogenic cells could be transferred to non-pathogenic cells, making them pathogenic

Question 12

Avery, MacLeod, & McCarty showed that pathogenic cells treated with _____ could no longer transform the non-pathogenic bacterial cells.

a. DNase
b. lipase
c. protease
d. RNase

Answer 12

a. DNase

Question 13

Hershey & Chase labeled protein with radioactive _____ and DNA with radioactive _____.

a. phosphorus; phosphorus
b. phosphorus; sulfur
c. sulfur; phosphorus
d. sulfur; sulfur

Answer 13

c. sulfur; phosphorus

Question 14

Hershey & Chase ultimately found radioactive DNA in the _____ meaning that the DNA was _____ the cells and was the genetic material.

a. pellet; inside
b. pellet; outside
c. solution; inside
d. solution; outside

Answer 14

a. pellet; inside

Question 15

What are genes?

Answer 15

Hereditary information is carried on chromosomes.
- Visible upon cell division in light microscopy
- Later determined to consist of DNA and protein
- Protein was assumed to be the genetic material!

Question 16

Conclusion from Griffith’s experiment

Answer 16

A substance from the dead S. pneumoniae cells caused heritable change in R cells.

The R cells were transformed:
- genetically altered by taking up the genetic material from an outside source
- Transforming principle