AP Bio Chapter 16-20 Test
In a nucleosome, the DNA is wrapped around
histones
Which of the following covalently connects segments of DNA?
ligase
Which of the following synthesizes short segments of RNA?
primase
An Okazaki fragment has which of the following arrangments?
5' RNA nucleotides, DNA nucleotides 5'
The nitrogenous base adenine is found in all members of which group?
ATP, RNA, and DNA
Which enzyme catalyzes the elongation of a DNA strand in the 5' --> 3' direction?
DNA polymerase III
To repair a thymine dimmer by nucleotide excision repair, in which order to do the necessary enzymes act?
Endonuclease, DNA polymerase I, DNA ligase
What determines the nucleotide sequence of the newly synthesized strand during DNA replication?
The nucleotide sequence of the template strand
What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
join Okazaki fragments together
Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of nucleotides in this sample will be thymine?
12
If proteins were composed of only 12 different kinds of amino acids, what would be the smallest possible codon size in a genetic system with four different nucleotides?
2
A possible sequence of the nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be
3' AAA-GAA-TAA-CAA 5'
A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is
3' UCA 5'
At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork?
5" ACGUUAGG 3'
In an analysis of the nucleotide composition of DNA, which of the following will be found?
A + C = G + T
What does transformation involve in bacteria?
Assimilation of external DNA into a cell
Which of the following removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments?
DNA polymerase I
Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following?
Gaps left at the 5' end of the lagging strand because of the need for a 3' onto which nucleotides can attach
Which of the following statements describes histones?
Histone H1 is not present in the nucleosome bead; instead it is involved in the formation of higher-level chromatin structures
the following scientists made significant contributions to our understanding of the structure and function of DNA. Place the scientists' names in the correct chronological order, starting with the first scientist to make a contribution.
II, I, III, V, IV
In his transformation experiments, what did Griffith observe?
Mixing a heat-killed pathogenic strain of bacteria with a loving nonpathogenic strain that can covert some of the living cells into the pathogenic form
Replication in prokaryotes differs from replication in eukaryotes for which of these reasons?
Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many
Why does the DNA double helix have a uniform diameter?
Purines pair with pyrimidines
What is mean by the description "antiparallel" regarding the strands that make up DNA?
The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand
Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that
The amount of A is always equivalent to T, and C to G
The DNA of telomeres has been found to be highly conserved throughout the evolution of eukaryotes. What does this most probably reflect?
The critical function of telomeres must be maintained
Which of the following can be determined directly from X-ray diffraction photographs of crystallized DNA?
The diameter of the helix
Which of the following separates the DNA strands during replication?
helicase
What kind of chemical bond is found between paired bases of the DNA double helix?
hydrogen
What amino acid sequence will be generated, based on the following mRNA codon sequence?
met-ser-ser-leu-ser-leu
Which of the following help to hold the DNA strands while apart while they are being replicated?
single-strand binding proteins
In his work with pneumonia-causing bacteria and mice, Griffith found that
some substance from the pathogenic cells was transferred to nonpathogenic cells, making them pathogenic
The leading and lagging strands differ in that
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
What is the function of DNA polymerase III?
to add nucleotides to the end of growing DNA strand
