CONCEPT ESSAYS:

   1992:                          L. PETERSON/AP BIOLOGY

	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.

  
  
   1992:                           L.PETERSON/AP BIOLOGY

	Survival depends on the ability of an organism to respond to changes in its 
	environment. Some plants flower in response to changes in day length. Some
	mammals may run or fight when frightened. For both of these examples,
	describe the physiological mechanisms involved in the response.

  
  
   1993:                            L. PETERSON/AP BIOLOGY

	Membranes are important structural features of cells.
	   (a) Describe how membrane structure is related to the transport 
	          of materials across a membrane.
	   (b) Describe the role of membranes in the synthesis of ATP in either
	          respiration or photosynthesis.

  
  
  
   1994:                            L. PETERSON/AP BIOLOGY
 
        Discuss how cellular structures, including the plasma membrane, specialized
        endoplasmic reticulum, cytoskeletal elements, and mitochondria, function 
        together in the contraction of skeletal muscle cells.

  
  
  
   1995:                            L. PETERSON/AP BIOLOGY

        The problems of survival of animals on land are very different from those of
        survivial of animals in an aquatic environment. Describe four problems associated
        with animal survival in terrestrial environments but not in aquatic environments.
        For each problem, explain an evolutionary solution
  
  
  
   1995:                            L. PETERSON/AP BIOLOGY

        Angiosperms (flowering plants) and vertebrates obtain nutrients from their 
        environment in different ways:

           (A)  	Discuss the type of nutrition and the nutritional requirements
                        of angiosperms and vertebrates.

           (B)  	Describe 2 structural adaptations in angiosperms for obtaining
                        nutrients from the environment. Relate structure to function.

           (C)  	Interdependence in nature is evident in symbiosis. Explain two 
                        symbiotic relationships that aid in nutrient uptake, using examples 
                        from angiosperms and/or vertebrates (Both examples may be angiosperms,
                        both may be vertebrates, or one may be from each group.)