11. Which of the following compound is readily available in the atmosphere?
A. NO3 B. NH3 C. NO D. N2

12.Humans facilitate the cycle of Carbon in the atmosphere by,
A. Planting trees
C. Burning fossil fuels
B. Throwing garbages into bodies of water D. Using organic fertilizers

13. Which of the following materials do not cycle up into the atmosphere?
A. Carbon B. Water C. Phosphorus D. Nitrogen

14. in the nitrogen cycle, the bacteria that live on the roots of plants change ATMOSPHERIC N (N2) into
A. Nitrates B. Nitrites
C. Ammonium D. Nitrous oxide

15. The most abundant element in the atmosphere is the
A. Oxygen B. Carbon
C. Magnesium D. Nitrogen

16. Organisms must have Nitrogen to make

A. Proteins and Amino acids B. Fats
C. Carbohydrates D. water

17. Which of following aids in the nitrogen fixation process?
A. Nitrosomas B. Clostridium
C. Rhizobium D. Nitrobacter

18. The process of nutrient loading into aquatic environments because of materiais leaching into bodies of water from agricultural lands causing algal bloom.
A. Biomagnification B. Eutrophication
C. Deposition D. material cycle

19. During water enters the atmosphere by evaporating from the leaves of plants.
A. Transpiration B. Respiration
C. Evaporation D. relaxation

20. The following contributes to the deposition of Carbon into the atmosphere, EXCEPT,
A. Burning of fossil fuel
C. Volcanoes and conversion to fossil fuels.
B. Respiration of animals
D. Photosynthesis

21. A chemical substance that an organism requires to live is called
A. Vitamins B. Nutrients
C. Steroids D. none of the above

22. The conversion of atmospheric nitrogen into a form used by plants is a process called
A. Denitrification B. Nitrogen Fixation
C. Nitrification D. Ammonification

23. The interaction of biotic and abiotic environment factors is best iilustrated by
A. A hen incubating her eggs
C. Two dogs fighting over a bone.
B. A young pine tree dying after an ice storm
D. A river's level rising due to excessive rainfall.

24. A garden ecosystem includes biotic and abiotic components. Choose the abiotic factor affecting life in this ecosystem.
A. earthworms in the soil
C. rich humus soit
B. animals on the water surface
D. floating plants

25. The interaction between the living things and non-living factors in the environment is known as;
A. Ecology B. Ecosystem
C. Interaction D. Interdependence​