102 Introductory Biology 



LIVING (ANIMATE) ORGANISMS 



NONLIVING (INANIMATE) 

 SUBSTANCES 



REPRODUCTION AND HEREDITY (GENETICS) 



All living organisms reproduce to form 

 new units of their own kinds. The 

 newly formed units or offspring tend 

 to resemble their parents because of 

 a continuity pattern carried from 

 generation to generation through the 

 numerous phenomena of heredity 

 (genetics). "All living organisms 

 arise only from living organisms." 

 So far, nothing comparable to genes, 

 etc., has been discovered in the non- 

 living world. The phenomena of 

 reproduction and heredity are in- 

 herent abilities of living protoplasm, 

 even though they may at times be 

 influenced by environmental factors 

 to a certain extent. They seem to be 

 initiated internally and for the most 

 part controlled internally. Living 

 organisms possess the qualities listed 

 above, but a nonliving object never 

 has more than a few of them, and 

 then in a somewhat modified way. 



Certain nonliving substances may at 

 times break into smaller pieces, but 

 are these phenomena truly compara- 

 ble to the complicated processes fre- 

 quently involved in giving origin to 

 offspring in the animate world? Are 

 these small bits capable of develop- 

 ing into a new individual as in the 

 the living world? Is there inheri- 

 tance, in the accepted sense, in these 

 inanimate materials? 



QUESTIONS AND TOPICS 



1. What is meant by a physical property of protoplasm? List all the physical 

 properties of protoplasm; attempt to understand the causes for each physical 

 property and the effects of such a property on the living protoplasm. 



2. Learn the correct pronunciation, derivation, and meaning of each new term 

 used in this chapter. 



3. Explain how the chemical composition of a living protoplasm depends on, 

 and varies with, the chemical substances taken in. 



4. What difficulties are encountered in attempting to analyze living protoplasm 

 chemically? Be sure that the results secured are accurate for the protoplasm 

 when it was still living (before the analyses were started). Might the chemi- 

 cal composition of protoplasm differ when dead from what it might be if the 

 same protoplasm could be analyzed and still be kept alive? 



5. Why is nitrogen an essential element for living matter? What general types 

 of food contain nitrogen? 



6. Which are more important, the organic or inorganic foods? Why? Give 

 the chief sources of mineral salts. 



7. Define (1) catalyst, (2) enzyme, (3) vitamin, (4) metabolism, (5) anab- 

 olism, (6) catabolism, (7) colloidal system, (8) sol and gel, (9) Brownian 

 movement, (10) adsorption, (11) emulsoid, and (12) diffusion. 



8. Describe the structure of an atom, including the characteristics of each of 

 its parts. 



