Natural resources Worksheet-6

Natural resources Worksheet-6

31. Eutrophication reduces the amount of ______ in water:

A. Dissolved Nitrates                   B. Dissolved Salt

C. Dissolved nitrates                    D. Dissolved oxygen

32. In Nitrogen cycle, which of the following bacteria is responsible for denitrification?

A. Nitrosomonas                          B. Nitrobacter

C. Pseudomonas                          D. Rhizobium

33. Oxidation of nitrogen to Nitrates is known as:

A. Nitrogen fixation                     B. Denitrification

C. Ammonification                      D. All of these

34. Nitrobacter bacteria present in soil can convert :

A. Nitrite to ammonia                 B. Nitrite to Nitrate

C. Nitrate to nitrite                      D. Ammonia to nitrite

35. CFC’s are commonly used in :

A. Propellants                               B. Formation of foam

C. Refrigerators                            D. All of these

36. Ozone hole refers to:

A. Decrease in thickness of ozone layer

B. Presence of hole in ozone layer

C. Conversion of ozone to oxygen

D. All of these

37. Soil erosion can be prevented by:

A. Afforestation

B. Deforestation

C. Construction of more buildings

D. All of these

38. Which of the following is true for humus:

A. It is required for binding of soil

B. Provide aeration to soil

C. It is a source of mineral

D. All of these

Answer Key:

31. D
32. C
33. A
34. B
35. D
36. A
37. A
38. D