ECOLOGICAL REALMS 



309 



that some of the same animals are found in both North America and Eurasia? 

 find other similarities ? 





rainfall, temperature range, and lists of the particular cereals, 

 fruits, and vegetables that can grow in the region are made 

 available to the farmer. 



Different parts of the world, each with its several life zones, are 

 known as realms or regions. Australia has long been set aside as 

 a distinct realm because its peculiar fauna and flora differ from 

 those in other parts of the earth. North America, South America, 

 the Arctic, the Antarctic, Oriental Africa, Eurasia, and Australia 

 constitute the world realms. Each of these regions has animals 

 and plants peculiar to itself, although resemblances are often found 

 in their inhabitants. The Eurasian fauna and flora resemble 

 closely those of North America. This is thought by geologists to 

 mean that in former times these regions were connected by land. 



Self-Testing Exercise 



Areas inhabited by certain (1) and (2) may be 



very (3) or very (4). Barriers that affect the range 



of plants and animals may be (5), (6), and (7). 



H- BIO — 21 



