502 



BIOLOGY AND HUMAN LIFE 



2. Control of plant and animal qualities 



Qualities that are important for human affairs 

 Management of domesticated or cultivated organisms 

 Plants 



Soil 



Conditioning 

 Fertilization 

 Cultivating 

 Surface covering 

 Water 

 Mulch 

 Hoeing 

 Irrigation 

 Dry farming 

 Animals 



Feeding ; protection 

 Selection 

 Examples 

 Best seeds 

 Sweetest beets 

 Hardiest wheat 

 Brightest flowers 

 Fastest horses 

 Longest cotton 



Planting 

 Rotation 



For soil preservation 

 For avoiding parasites 

 Protection 



Adverse conditions 

 Enemies 

 Fungi 

 Insects 



Yellowest corn grains 

 Longest-legged hounds 

 Shortest-legged sheep 

 Rust-resisting wheat 

 Cows with most milk 

 Cows with most fat in milk 

 Cattle immune to Texas fever 



Finest wool 

 Need for constant selection 



To avoid deterioration ; for possible improvement 

 3. Sources of types for selection 

 Mutations, or sports 

 Importation of new forms 

 Artificial stimulation to variation 

 Changed conditions 

 (Hybridization, which rests on understanding of heredity) 



QUESTIONS 



1. In what ways do the members of your class resemble one another? 



2. In what ways do the members of your class differ ? 



. 3. How can you measure the differences or resemblances among 

 individuals ? 



