DNA Structure and Function/Replication Quiz A

Which is not a component of a nucleotide?

• codon

• sugar

• phosphate group

• nitrogen base

A repeating non-coding sequence that serves as a protective cap at the end of a chromosome is known as a

• chromatin

• telomere

• chromatid

• DNA

The end of a DNA or RNA strand where nucleotides can be added during replication

• nucleotide

• telomere

• 5’ end

• 3’ end

An Okazaki fragments are

• the parts of the leading strand where replication occurs

• the lagging strand of DNA replication that contains gaps within it

• the parts of the DNA strand where hydrogen bond is broken

• the parts of the lagging strand that help bond the nucleotides together after they come together

The region on the surface of an enzyme where the substrate binds

• ligand

• inhibitor

• product

• active site

Which is a purine? (Check all that apply)

• adenine

• thymine

• guanine

• cytosine

_________________________ attaches the fragments to each other

• DNA ligase

• DNA primase

• DNA polymerase

• Helicase

Chromosomes get shorter every time they replicate

• True

• False

Erwin Chargaff investigated the nucleotide composition of DNA. He analyzed DNA from various organisms and measured the relative amounts of adenine (A), guanine (G), cytosine (C), and thymine (T) present in the DNA of each organism. Table 1 contains a selected data set of his results. Which of the following statements best explains the data set?

• Since the %A and the %G add up to approximately 50 percent in each sample, adenine and guanine molecules must pair up in a double-stranded DNA molecule.

• Since the %A and the %T are approximately the same in each sample, adenine and thymine molecules must pair up in a double-stranded DNA molecule.

• Since the %(A+T) is greater than the %(G+C) in each sample, DNA molecules must have a poly-A tail at one end.

• Since the %C and the %T add up to approximately 50 percent in each sample, cytosine and thymine molecules must both contain a single ring.

Which of the following best explains how continuity of genetic information in cells is ensured across generations?

• Replication uses a parental strand of DNA as a template to create a new strand of DNA.

• DNA molecules are shaped like a double helix with a constant diameter throughout.

• Transcription copies the information in DNA into an RNA transcript.

• Cells contain different polymerases for DNA replication and transcription.