Student Guide for Topic 8: What is Life?

CLAR 102 - Inquiry in the Natural World – Spring 2003 - Lapennas

Topic objectives:

 

1.  Know what unique characteristics life has that people have been trying to explain for a long time

2.  Know what general hypotheses about life people came up with to explain these characteristics.

3.  Know: the difference between mechanistic and vitalistic explanations of life; why many scientists did not accept early mechanistic explanations of life; and what developments led later scientists to accept the mechanistic explanation of life.

4.  Know about: the cell theory; synthesis of organic molecules; the fermentation controversy; cryptobiosis; spontaneous generation; and how discoveries concerning each of these during the 19th century helped a mechanistic understanding of life replace other explanations.

 

 

Day 2 (Friday, 14 March) reading assignment:

1.  Trefil, J. and RM Hazen, The Sciences, 3rd ed, pp. 443-446; 468-482; 489-497.

2.  Benington, J, What is Life? http://web.sbu.edu/physics/faculty/dimattio/Clare102/physics.dimattio-sp03.htm

 

Day 2 active learning exercises:

 

1.  What remarkable characteristics do living things have that are not found in non-living matter?  Which two of these are most fundamental?

2.  What invention made the discovery of cells possible?  Draw a simple picture of a cell and its major parts.  What is/are the primary function(s) of each part?

3.  What are “organic” molecules?  How have our ideas about where they can be synthesized changed over time?

4.  What are the 4 main types of large organic molecules in cells?  What is/are the primary function(s) of each?

5.  What is “cryptobiosis”? Identify several examples.  What general conclusion about life is supported by the phenomenon of cryptobiosis?

 

 

Day 3 (Monday, 17 March) reading assignment:

Harry Collins and Trevor Pinch, “The germs of dissent: Louis Pasteur and the origin of life,” from The Golem: What Everyone Should Know About Science, Cambridge: Cambridge Univ. Press, 1993.

http://web.sbu.edu/physics/faculty/dimattio/Clare102/physics.dimattio-sp03.htm

Day 3 discussion questions:

 

1.  Describe Pasteur’s evidence against spontaneous generation.

2.  Describe Pouchet’s evidence in favor of spontaneous generation

3.  What aspects of Pouchet’s experiments did Pasteur challenge and why?

4.  At the end of the chapter, Collins and Pinch say that, “Pasteur was a great scientist but what he did bore little resemblance to the ideal set out in modern texts of scientific method. It is hard to see how he would have brought about the changes in our idea of the nature of germs if he had been constrained by the sterile model of behavior which counts, for many, as the model of scientific method.” What do they mean by this? Give specific examples.