DNA Replication

Which of the following must happen first in order for DNA replication to occur?

• DNA polymerase binds to the leading strand
• DNA is unwound
• Hydrogen bonds form between bases
• chromosomes condense

Okazaki fragments form on the:

• lagging strand
• leading strand
• base-pairs
• 5' end

Which of the following is required for DNA replication to occur?

• DNA helicase
• DNA ligase
• DNA polymerase
• all of these

A nucleotide consists of:

• a nitrogen base
• a nitrogen base and a sugar
• a nitrogen base, sugar, and phosphate
• two nitrogen bases, a sugar, and a phosphate

The "rungs" of the DNA ladder are made of:

• phosphates and bases
• sugars 
• sugars and phosphates
• bases

A DNA strand has the following bases: A A G C C A. What are the bases on its complimentary strand? 
 

• T T G C C A
• A C C G A A 
• T T C G G T 
• C C A T T C

If a DNA molecule is found to be composed of 40% thymine, what percentage of guanine would be expected. 

• 10%
• 20%
• 40%
• 80%

The enzymes that break hydrogen bonds and unwind DNA are:

• primers
• ligases
• helicases
• polymerases

DNA replication results in:

• 2 completely new DNA molecules
• 2 DNA molecules that each contain a strand of the original
•  1 new DNA molecule, 1 old molecule is conserved
• 1 new molecule of RNA

During replication, what enzyme adds complimentary bases?

• helicase
• synthesase
• ligase
• polymerase