Unit 7 - DNA/RNA & Protein Synthesis Test Review

If 35% of an organism’s DNA is thymine (T), what is the percentage of guanine (G)?

• 15%

• 35%

• 70%

• 50%

The double-helix model of the DNA molecule resembles a twisted ladder. What makes up the 'backbone' or sides of the 'twisted ladder'?

• paired phosphate groups only

• paired nitrogenous bases

• paired sugars only

• alternating sugars and phosphate groups covalently bonded

This figure shows a section of a double-stranded DNA molecule. What aspects of the structure of DNA are explained by this model?

• Paired nucleotides are held together by weak ionic bonds.

• Adenine is paired with cytosine and guanine is paired with thymine.

• Paired nitrogenous bases are held together by hydrogen bonds.

• The numbers of each nucleotide determine genetic information.

Tags

NGSS.HS-LS1-1

How does the double-helical structure of DNA explain how they are copied/replicated?

• It is semi-conservative; Because of base pairing, each strand has all the information to serve as a template for the synthesis of the other strand.

• It is conservative; Each strand receives the information from the DNA polymerase attached to the replication fork.

• It is semi-conservative; The nitrogenous bases on one strand are copied to the other strand.

• It is non-conservative; The nitrogenous bases line up on each strand and are attached to each other.

How does DNA replication differ between prokaryotes and eukaryotes?

• The base-pairing rules are different between prokaryotes and eukaryotes.

• Only prokaryotes rely on enzymes such as DNA polymerase.

• Only eukaryotes rely on enzymes such as DNA polymerase.

• Eukaryotes use multiple replication forks to replicate a larger volume (amount) of DNA.

The sequence of nitrogenous bases on a portion of a strand of DNA is shown in the diagram. From left to right, what is the corresponding sequence of the complementary DNA strand?

GGTGACT

• C C A C T G A

• G G U G T A T

• G G T G A C T

• T T A G A T C

The diagram shows a model of DNA replication. Which of the following labels should NOT be added to the model?

• DNA polymerase

• Replication fork

• RNA polymerase

• Nitrogenous bases

A segment of DNA has this sequence: ATA GCA CAT GTA. What is the mRNA sequence transcribed from this segment?

• TAT CGT GTA CAT

• TAT GCT CTA GAT

• UAU CGU GUA CAU

• UAU GCU CUA CAU

Which of the following best describes Chargaff's base-pairing rule?

• In DNA molecules, [T] > [A] > [G] > [C]

• In DNA molecules [A] = [G], and [C ] = [T]

• In DNA molecules, [A] = [T], and [C ] = [G]

• In single-stranded DNA molecules, [A] = [T] = [C ] = [G]

Alvin is studying a model of the chemical structure of a common nucleic acid. He observes that the nucleic acid consists of four nitrogenous bases: adenine (A), cytosine (C), guanine (G), and uracil (U). Alvin’s observation most strongly supports which of these conclusions?

• The nucleic acid is a form of RNA, and is not DNA.

• None of them.

• The nucleic acid is either RNA or DNA.

• The nucleic acid is DNA, and is not RNA.