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BIOLOGY FOR BEGINNERS 



SUMMARY 

 Development of the branches of the Animal Kingdom. 



Branch. Examples (in notes) 



Protozoa 



Sponges 



Hydra 

 Worms 

 Molluscs 



Arthropods 



Vertebrates 



Line of development. 



Specialized single cells. 



Groups of slightly specialized cells. 



Larger size, colonial habit. 



Three-layered body wall, tissues. 



Systems of organs, sense organs. 



Protection, inactive, low intelli- 

 gence. 



Jointed exo-skeleton, active. 



High developed senses and in- 

 stinct. 



Size and brain development lim- 

 ited. 



Internal skeleton. 



No limit to size of brain. 



Less protected but more intelli- 

 gent. 



Classes of vertebrates 



Pisces 



Amphibia 



Reptilia 



Aves 



Mammals 

 Characteristics of vertebrates 



Spinal column 



Internal skeleton 



Dorsal nervous system. 



Two body cavities 



Two pairs of limbs or fewer. 



Representatives 



Fishes, 



Frogs, toads, salamanders. 



Snakes, turtles, lizards. 



Birds. 



Rat, cow, cat, man. 



Sense organs on head. 

 Jaws not developed from limbs. 

 Eyelids, separate teeth. 

 Ventral heart, red blood. 



