2-Maruza Biosfera. Tabiiy resurslar, ulardan oqilona foydalanish va atmosfera muhofazasi. Suv va Tuproq resurslari va uni muhofazasi. O‘simlik, hayvonot dunyosi va ularni muhofaza qilish

Endangered Species
To help prevent extinctions, it is importantto identify species that could soon 
disappear. A species indanger of becoming extinct is classified as an 
endangered species.
The 
African black rhinoceros, shown in 
Figure 7, 
is endangered. 
Rhinoceroses are plant eaters. They use their horns to battle eachother for territory and to protect 
themselves against lions andother predators. For centuries, humans have considered rhinoceroshorn 
to be a rare treasure. It is so valuable that poachers continue 
to hunt and kill these animals, even though sellingrhinoceros horn is against international law. In 
1970, there wereabout 100,000 black rhinoceroses in Africa. By the year2000, fewer than 3,000 were 
left. 

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Threatened Species
If a species is likely tobecome endangered in the near future, it is classifiedas a 
threatened species. 
The Australian koala, shownin 
Figure 8, 
is threatened. People once hunted 
koalasfor their fur. In the 1930s, people realized the koalawas in danger. Laws were passed that 
prohibited thekilling of koalas, and the koala populations began torecover. Koalas rely on certain 
species of Australianeucalyptus trees for food and shelter. After the 1930slaws were passed, 
Australia‘s human population grewand the koala‘s habitat began to disappear. By the year2000, 
nearly two-thirds of the koala‘s habitat hadbeen lost to logging, agriculture, cities, and roads.
 
Nazorat savollari: 
1. Hayvonot dunyosining qanday ahamiyati bor? 
2. O‗zbekiston hayvonot olamida qancha tur hayvonlar bor? 
3. O‗zbekistonda hayvonot olamini muhofaza qilish borasida qanday ishlar olib 
borilmoqda? 
4. O‗zbekiston hayvonot olamida qanday turlar yo‗qolib ketgan?