AP BIOLOGY OUTLINE FOR DNA:

  CHEMICAL NATURE OF THE GENE
	
	A.  Watson-Crick Model of Nucleic Acids
	B.  Replication of DNA molecule
	C.  Genetic code and chemical nature of mutation
	D.  Control of protein synthesis:
	       	transcription and translation
	E.  Recombinant DNA techniques
	F.  Gene regulation:
		structural and regulatory genes
	G.  Principles of transformation and transduction

ESSAY QUESTIONS:

1960:
	Discuss the gene, with regard to structure, duplication, mutation, and 
	nature of action.
1962:
	Deoxyribonucleic acid or DNA has been described as the chemical basis 
	of heredity. Discuss present-day concepts regarding its:
	   	a.  	chemical nature and physical structure
	   	b.  	mode of duplication
	   	c.  	relationship to protein synthesis
1965:
	Biologists and biochemists have made outstanding progress within the past 		quarter century in elucidating  principles and structures which govern the 	activities of living matter. These areas of progress include the structure and 
	code of the DNA molecule. Discuss this development and its impact on biological 	thought and progress. Your answer should include:
	   	a. 	a brief account of the development
	   	b. 	the names of the most prominent investigators involved
	   	c. 	the nature of its impact on biology
1965:
	Discuss the role of each of the following in protein synthesis:
	   	a. 	soluble or transfer RNA
	   	b. 	messenger RNA
	   	c. 	ribosomes
	   	d. 	ATP
1967:
	The formation of Watson-Crick complementary base pairs between single 	
	strands of molecules of nucleic acids occurs in at least three separate reactions. 	
	Discuss each of these reactions from the following points of view:
	   	a. 	the type of nucleic acids involved
	  	b. 	the role of each nucleic acid in the duplication of cellular constituents









1969:
	Proteins and nucleic acids are fundamental molecules of the living state.
	   a. 	Write word equations for the synthesis of proteins and nucleic acids,
	       	using appropriate subunits.
	   b. 	A wide variety of macromolecules exists in proteins and nucleic acids.
	       	For each group, explain how it is possible to have such great variety of
	       	structure with a relatively small number of different subunits.
	   c. 	Proteins functioning as enzymes exhibit precise specifications. Discuss
	       	the levels of structural organization within proteins which are 		
	       	responsible for specific molecular interaction.
1974:
	Describe protein synthesis in terms of molecular structures of the 
	nucleic acids and using a specific example, explain how a new phenotypic 	characteristic may result from a change in DNA.
1977:
	Proteins are composed of amino acid subunits which form stable 
	three-dimensional structures.
	   a. 	Describe how the genetic instructions coded in DNA are translated into the 
	       	primary structure (sequence of amino acid subunits) of a protein molecule.
	   b. 	Explain how interactions among the individual amino acid subunits influence 
	       	the transformation of the molecule into its three-dimensional structure and 
	       	how they stabilize it.
1979:
	In relation to the chemical nature of the gene, describe:
	   a. 	the chemical structure of the gene
	   b. 	the replication (self-copying) of the gene
	   c. 	gene mutations, including chromosomal aberrations
1982:
	A portion of a specific DNA molecule consists of the following sequence of 	nucleotide triplets:
			TAC   GAA   CTT    CGG    TCC
	This DNA sequence codes for the following short polypeptide:
			methionine - leucine - glutamic acid - proline - arginine

	Describe the steps in the synthesis of this polypeptide. What would be the effect 
	of a deletion or an addition in one of the DNA nucleotides? What would be the 
	effect of a substitution in one of the nucleotides?
1984:
	Experiments by the following scientists provided critical information concerning 
	DNA. Describe each classical experiment and indicate how it provided evidence 
	for the chemical nature of the gene.
	   a.  	Hershey and Chase - bacteriophage replication
	   b.  	Griffith and Avery - bacterial transformation
	   c.  	Meselson and Stahl - DNA replication in bacteria
1985:
	Describe the operon hypothesis and discuss how it explains the control of 	messenger RNA production and the regulation of protein synthesis in 
	bacterial cells.
1986:
	Describe the biochemical composition, structure, and replication of DNA. 
	Discuss how recombinant DNA techniques may be used to correct a point 	mutation.
1987:
	Describe the production and processing of a protein that will be exported from a 
	eukaryotic cell. Begin with the separation of the messenger RNA from the DNA
	template and end with the release of the protein at the plasma membrane.


1990:
	Describe the steps of protein synthesis, beginning with the attachments of a 
	messenger RNA molecule to the small subunit of a ribosome and ending with the 
	release of the polypeptide from the ribosome. Include in your answer a discussion 
	of how the different types of RNA function in this process. 
1992:
 	Biological recognition is important in many processes at the molecular, cellular,
	and organismal levels. Select three of the following, and for each of the three that
	you have chosen, explain how the process of recognition occurs and give an 	example.
	a.    	Organisms recognize others as members of their own species.
	b.    	Neurotransmitters are recognized in the synapse.
	c.    	Antigens trigger antibody responses.
	d. 	Nucleic acids are complementary.
	e.    	Target cells respond to specific hormones.
1995:
	The diagram below shows a segment of DNA with a total length of 4,900 base 
	pairs. The arrows indicate reaction sites for restriction enzymes (enzyme X 
	and enzyme Y).


	      	      Enzyme        Enzyme              Enzyme                   Enzyme		
 DNA Segment	              X	     Y		  X		    X			
		________________________________________________
Length (base pairs)   400	        500	              1,200	          1,300		1,500

	(A)  	Explain how the principles of gel electrophoresis allow for the separation 
		of DNA fragments.

	(B)	Describe the results you would expect from the electrophoretic 
		separation of fragments from the following treatments of the DNA 
		segment above. Assume that the digestions occurred under appropriate
		conditions and went to completion.

			   I   DNA digested with only enzyme X
			  II.  DNA digested with only enzyme Y
			 III.  DNA digested with enzyme X and enzyme Y combined
		                 IV.  Undigested DNA

	(C)	Explain both of the following.

		(1)  	The mechanism of action of restriction enzymes.

		(2)  	The different results you would expect if a mutation occurred 
		         	at the recognition site for enzyme Y.