DNA REPLICATION

Why does DNA need to be replicated?

• so mRNA can make a copy of it

• so each cell that results from cell division has the exact DNA

• so that new nitrogen bases can be synthesized

• so that new amino acids can be synthesized

What happens first in DNA replication?

• DNA must "unzip" (double helix strands separate into single strands)

• nitrogen bases must be synthesized

• amino acids must be synthesized

• none of the above

After the DNA double helix separates, each single strand begins to

• form an RNA molecule

• form proteins when tRNA brings amino acids to the unzipped DNA molecule.

• form a double strand when free nitrogen bases in the nucleus find their complementary bases in each single strand.

• travel to the cytoplasm to find their corresponding nitrogen bases

After the DNA double helix separates, each single strand begins to

• form an RNA molecule

• form proteins when tRNA brings amino acids to the unzipped DNA molecule.

• form a double strand when free nitrogen bases in the nucleus find their complementary bases in each single strand.

• travel to the cytoplasm to find their corresponding nitrogen bases

What is unique about the new left and right helices that are forming in this replicating DNA molelcule?

• They are made of RNA.

• They have different base pair arrangements, allowing for genetic diversity.

• They have the same exact base pair arrangements.

• The arrangement of base pairs is totally random.

The fact that the left side of this DNA molecule reads 5' at the top and 3' at the bottom and the right side is the opposite reflects

• DNA's antiparallelism

• DNA's complementary base pairs

• DNA's twisting structure

• DNA's organic nature

Adenine always pairs with ______________, and cytosine always pairs with ___________ in a DNA molecule.

• adenine, uracil

• guanine, thymine

• thymine, guanine

• uracil, guanine

DNA replication is represented by which image above?

• (a)

• (b)

• both (a) and (b)

• neither (a) nor (b)

What is the role of helicase in DNA replication?

• it produces the nitrogen bases used in replication

• it joins the two DNA strands together

• it unzips the DNA molecule so the bases can be exposed

• it produces new DNA molecules

Which enzyme helps the formation of the replicated DNA molecule?

• RNA polymerase

• DNA polymerase

• helicase

• uracil