ap bio chapter 16 quiz

Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately, what percentage of the nucleotides in this sample will be thymine?

12

In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts?

A and B only (DNA does not contain sulfur, whereas protein does. / DNA contains phosphorus, but protein does not)

which of the following best describes thea ddition of nucleotides to a growing DNA chain?

A nucleotide triphosphate is added to the 3' end of the DNA, releasing a molecule of pyrophosphate

Phage with labeled proteins or DNA was allowed to infect bacteria. It was shown that the DNA, but not the protein, entered the bacteria cells, and was, therefore, the genetic material

Alfred Hersey and Martha Chase

For a science project, two students decided to repeat the Hersey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. Why won't this experiment work?

Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.

Avery and his colleagues purified various chemicals from pathogenic bacteria and showed that ______ was (were) the transforming agent

DNA

Which enzyme catalyzes the elongation of a DNA strand in the 5' to 3' direction?

DNA polymerase

removes the RNA nucleotides from the promer and adds equivalent DNA nucleotides tot he 3' end of Okazaki fragments

DNA polymerase I

In DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine

Erwin Chargaff

Chemicals from heat-killed S cells were purified. The chemicals were tested for the ability to transform live R cells. The transforming agent was found to be DNA.

Oswald Avery, Maclyn McCarty, and Colin

what kind of molecule or substance is the primer that is used to initiate the synthesis of a new DNA strand?

RNA

Which of these mechanisms ensures that the DNA sequence in the genome remains accurate?

all of the above (proofreadig during DNA replication / mismatch repair / excision repair / complementary base pairing during DNA replication)

which of the following statements about telomeres is correct?

b and c (they are present at the ends of eularyotic chromosomes / they can be extended by an enzyme called telomerase)

the leading and the lagging strands differ in that

both A and C (the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction / the leading strand is synthesized continuously, whereas the lagging strand is synthesized in short fragments that are ultimately stitched together)

After mixing a heat-killed phosphorescent strain of bacteria with a living non-phosphorescent strain, you discover that some of the living cells are now phosphorescent. The best evidence that the ability to fluoresce is a heritable trait would be an observation that

descendants of the living cells are also phosphorescent

Seperates the DNA strands during replication

helicase

What kind of chemical bond is found between the paired bases of the DNA double helix?

hydrogen

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent

leading strands and Okazaki fragments

covalently connects segments of DNA

ligase

In his transformation experiments, Griffith observed that

mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form.

DNA-cutting enzymes used in the repair of DNA damage

nuclease

synthesizes short segments of DNA

primase

the Y-shaped structure where the DNA double helix is actively unfoured during (DNA replication is called the

relication fork

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in its

sequence of bases

which of the following help to hold the DNA strands apart while they are being replicated?

single-strand binding proteins

The strands that make up DNA are antiparallel. This means that

the 5' 3' direction of one strand runs counter to the 5' 3' direction of the other strand

the difference between ATP and the nucleotide triphosphates used during DNA synthesis is that

the nucleoside triphosphate have the sugar deoxyribose; ATP has the sugar ribose

What determines the nucleotide sequence of the newly synthesized strand during DNA replication?

the nucleotide sequence of the template strand

What is the function of DNA polymerase?

to add nucleotides to the end of a growing DNA strand

a eukaryotic cell lacking telomerase would

undergo a reduction in chromosome length