Introduction to rocks. 

 - Videocassette (VHS)(ca. 120 min.) :sd., col. 1/2 in. 
<br/><br/> Introduction to rocks, 100's of rock varieties compose the earth. 6 programmes in one tape. 1. Introduction to rocks. 2. Energy and nutrients ecology. 3. Elementry genetics. 4. Human blood groups. 5. The ecology of streams. 6. The cell and the structure. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Rocks.<br/>Genetics.<br/>Cell.