DNA Structure/Replication Quiz

Question 1

What are the four macromolecules?

Answer 1

Carbohydrates
Lipids
Protein
Nucleic Acids (DNA/RNA)

Question 2

What is the full name for DNA?

Answer 2

Deoxyribonucleic acid

Question 3

What does DNA do?

Answer 3

• It is found in all living material and contains the genetic material
• It directs and controls the cellular functions
• It is the only molecule capable of making an exact copy of itself

Question 4

Where is DNA found?

Answer 4

In the nucleus

Question 5

What are histones?

Answer 5

Histones are proteins that DNA wraparound to form nucleosomes. These proteins help with the packaging of chromosomes (in eukaryotic cells).

Question 6

How is a nucleosome formed?

Answer 6

DNA wraps around a set of 8 histones twice to form a nucleosome. These help the DNA fit inside the nucleus.

Question 7

What is a chromatin?

Answer 7

Nucleosomes that are packed into coiled fibers, found in the nucleus.

Question 8

How are chromosomes formed?

Answer 8

Chromatin fibers condensing at the time of reproduction.

Question 9

What is the DNA backbone made of?

Answer 9

Phosphates and deoxyribose sugars.

Question 10

What is the distance between each pair of bases?

Answer 10

0.34 nm

Question 11

How often does DNA make a full twist? How many base pairs is this?

Answer 11

Every 3.4nm, 10 base pairs.

Question 12

What are the 4 nitrogen bases?How do they pair? How many nitrogen bonds between them?

Answer 12

Guanine and Cytosine (3 bonds)
Adenine and Thymine (2 bonds)

Question 13

How far apart are the two sides of DNA?

Answer 13

2nm (the diameter of DNA)

Question 14

What is DNA made up of?

Answer 14

Nucleotides

Question 15

What are nucleotides comprised of?

Answer 15

A phosphate group, a deoxyribose sugar, and a nitrogen base.

Question 16

What is a pyrimidine?

Answer 16

Made up a single nitrogen ring (Cytosine and Thymine)

Question 17

What is a purine?

Answer 17

Made up of double nitrogen rings (Adenine and Guanine)

Question 18

What is a polymer?

Answer 18

Something made up of repeating units. DNA is a polymer because it is made up of nucleotides.

Question 19

Is the sugar end 3’ or 5’?

Answer 19

3’

Question 20

Is the phosphate end 3’ or 5’?

Answer 20

5’

Question 21

If one strand is 5’——-3’, then what is the opposite strand?

Answer 21

3’——-5’, because DNA is antiparallel.

Question 22

What does antiparallel mean?

Answer 22

The strands go in opposite directions.

Question 23

During which phase of the cell cycle does DNA replication take place?

Answer 23

Synthesis

Question 24

What did Stahl and Meselson do for DNA replication?

Answer 24

They demonstrated that the DNA was semi-conservative.

Question 25

What does semi-conservative mean?

Answer 25

The process results in two strands, each with one half of the DNA strand being "old" and half is "new".

Question 26

What does gyrase do?

Answer 26

Relieves tension.

Question 27

What does helicase do?

Answer 27

It attaches to the origin of replication and separates the double stranded DNA molecule by breaking the hydrogen bonds between the base pairs.

Question 28

What does SSBP do?

Answer 28

It binds to the single strands of DNA to prevent the two sides from rejoining.

Question 29

What does anneal mean?

Answer 29

Connecting/joining

Question 30

What does primase do?

Answer 30

Primase places RNA primers to indicate to DNA polymerase III where to join nucleotides.

Question 31

What does DNA polymerase III do?

Answer 31

Polymerase III joins free floating nucleotides to the parent strand according the Chargraff's rule.

Question 32

In RNA, which nitrogen base does uracil replace?

Answer 32

Thymine (think gold)

Question 33

What does DNA polymerase I do?

Answer 33

Removes the RNA primers and fills them in with the correct base pairs.

Question 34

What does ligase do?

Answer 34

Ligase connects the gaps between the Okazaki fragments and the nucleotide segments by creating phosphodiester bonds.

Question 35

What is a replication bubble?

Answer 35

The opened up area created by helicase.

Question 36

How long can RNA primers be?

Answer 36

Anywhere from 10-60 nucleotides long.

Question 37

In which direction can DNA polymerase III exclusively work?

Answer 37

5' to 3'

Question 38

What is the leading strand?

Answer 38

The strand that is able to be synthesized continuously.

Question 39

What is the lagging strand?

Answer 39

The strand synthesized discontinuously in the short segments called Okazaki fragments.

Question 40

What is the name of the sugar in DNA?

Answer 40

Deoxyribose sugar.

Question 41

What bonds to the first carbon on sugar?

Answer 41

A nitrogen base.

Question 42

What is the name of the bond between the sugar and the nitrogen base?

Answer 42

A glycosol bond.

Question 43

Where is the phosphate attached to the sugar?

Answer 43

The fifth carbon.

Question 44

What type of bond is located between the sugar and phosphate?

Answer 44

Phosphodiester bond.

Question 45

In DNA, what is found at the 2nd carbon?

Answer 45

H (hydrogen)