BIOL100 PRACTICE QUIZ #1
1.  When Fred Griffith injected mice with a mixture of dead, pathogenic S 
cells and living nonpathogenic R cells of Streptococcus pneumoniae, he 
discovered that:
a) the mice lived  b) the previously harmless R cells had inherited the ability 
to kill the mice, by the transfer of the the DNA from the dead S cells to the 
live R cells  c) the mice died because in the mixture of dead S cells a very 
small % of the cells did not die, and the few live S cells killed the mice

2.  Which of the following statements is false?
a) protein molecules contain no phosphorus  b) Hershey and Chase 
discovered that 35S and not  32P had been incorporated into the hereditary 
system of the bacteria  c) bacteriophages are viruses that inject their DNA into 
bacteria and use the bacterial translational machinery to make viral proteins  
d)  an isotope is an atom which has gained 1 or 2 neutrons, and to get rid of 
the extra neutron weight it will decay  releasing radioactivity e) viruses are 
particles of nucleic acid and protein

3.  DNA varies from species to species in its:
a) base-pair bonding  b) relative amounts of nucleotide bases  c) sequence of 
base pairs  d) a and c only  e) b and c only

4.  DNA synthesis:  a) proceedes 3ê-->5ê  b) requires a RNA primer  c) requires 
RNA polymerase  d)  is continuous on both newly synthesizing DNA strands

5.Transcription of a gene involves
a) making an mRNA that is complementary to the gene   b) matching tRNA's 
having the complementary anticodon to the appropriate mRNA codon   c) 
unzipping of the two strands of a DNA molecule and replicating each strand   
d) making a peptide bond between the amino acids in the growing 
polypeptide chain   e) none of the above 

6.The process of converting mRNA into protein is 
called___________________, and occurs in the 
_________________of the cell.   How many different codons are 
their?______.Since their are only 20 amino acids, can several codons be used 
to specify one amino acid? (yes or no)________ 

7.  Every tRNA has ____I___  which is complementary to ___II_____  on 
the mRNA and this is responsible for the accuracy of protein synthesis.
		 I					II
	a.  an amino acid		                 an anticodon
	b. an anticodon		                  an amino acid
	c. a codon			                an anticodon
	d. a codon			               CCA sequence
	e. an anticodon		                a codon
8.  A typical ribosome has two subunits:  A small subunit, and a large subunit.    
The large subunit has two sites (A and P)  that can bind:    a) DNA  b) rRNA  
c) tRNA  

9.  The step in translation when a peptide bond forms between the amino acid 
attatched to the tRNA in the_____(A or P) site of the ribosome and the 
growing polypeptide attatched to the tRNA in the____  (A or P) site is called 
elongation.  During this time the now-uncharged tRNA in the____(A or P) 
site is released from the ribosome and the ribosome moves one codon down 
the mRNA in an ATP-dependent process called translocation. 

10.  If the codon for isoleucine is AUC, then a possible anticodon of the tRNA 
carrying isoleucine is _________, and a possible nucleotide sequence in the 
corresponding gene is _________.
a) AUC; ATC   b) UAG; TAG   c) TAG; TAG   d) TAG; UAG   e) impossible to 
determine




Extra Credit (worth 1.5 points)

1.  After three replications of a single DNA molecule, what percent of the 
resulting double helices contain one strand of the –original” DNA?
a) 0 %  b) 25%  c) 50%  d) 75%  e) 100%


2.  If synthesis is moving in this direction (---->), which strand below (top or 
bottom) is the template for the discontinuous strand during DNA 
replication?_____________                      
                                                                         5ê----------------------3ê
                                                                         3ê----------------------5ê


3.  What would happen during protein synthesis if the amino acid linked to 
its transfer RNA were chemically changed while still remaining attached to 
the tRNA (for example, from cysteine to alanine) ?
a) The tRNA would no longer be able to function in protein synthesis   b) The 
tRNA would now base pair with the mRNA codon coding for alanine   c) The 
binding of the tRNA to rRNA would be blocked   d) cysteine would be 
inserted into the amino acid sequence of the new protein where alanine 
should be   e) alanine would be inserted into the primary structure of the new 
protein in place of cysteine





NAME:______________________