Evolyutsiyon ketma- ketlikning to’g’ri qatorini belgilang.
1- kovakichlilar; 2- yassi chuvalchanglar; 3- sodda organizmlar; 4- mollyuskalar; 5- halqali chuvalchanglar; 6- to’garak chuvalchanglar;

1. 3,2,1,4-5-6
2. 3,2,1-5-4-6
3. 3,2,1-5-6-4
4. 3,1,2-5-4-6