25 notecards = 7 pages (4 cards per page)
A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be
c. 3' AAA-GAA-TAA-CAA 5'.
Which of the following statements describes the eukaryotic chromosome?
b. It consists of a single linear molecule of double-stranded DNA plus proteins.
What is a ribozyme?
d. an RNA with enzymatic activity
Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base?
e. DNA in both daughter cells would be radioactive.
A frameshift mutation could result from
b. either an insertion or a deletion of a base.
At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork:
a. 5' A C G U U A G G 3'
Which of the following investigators was/were responsible for the following discovery?
e. Erwin Chargaff
Why might a point mutation in DNA make a difference in the level of protein's activity?
b. It might substitute an amino acid in the active site.
The leading and the lagging strands differ in that
d. 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 genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?
c. A gene from an organism can theoretically be expressed by any other organism.
What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
e. It joins Okazaki fragments together.
A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is
c. 3' UCA 5'.
In his transformation experiments, what did British medical officer F. Griffith observe?
b. Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form.
When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur?
a. Its signal sequence must target it to the ER, from which it goes to the Golgi.
The following question refers to this figure of a simple metabolic pathway:
In a nucleosome, the DNA is wrapped around
Which of the following is not true of RNA processing?
c. Exons are cut out before mRNA leaves the nucleus.
Which of the following would you expect of a eukaryote lacking telomerase?
e. a reduction in chromosome length in gametes
What amino acid sequence will be generated, based on the following mRNA codon sequence?
A mutation results in a defective enzyme A. Which of the following would be a consequence of that mutation?
d. an accumulation of product A and no production of products B and C
What is meant by the description "antiparallel" regarding the strands that make up DNA?
c. The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that
a. many noncoding stretches of nucleotides are present in mRNA.
Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?
Which component is not directly involved in translation?
For a science fair project, two students decided to repeat the famed Hershey and Chase experiment with bacteriophages, 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?
d. Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.