BIOCHEMISTRY QUIZ NITROGEN CYCLE 1 Assimilation is indicated

BIOCHEMISTRY QUIZ -NITROGEN CYCLE-

1 Assimilation is indicated by the letter(s) _____. a. A b. B c. C d. C and D e. D and E

2 Nitrogen-fixing bacteria is(are) indicated by the letter(s) _____. a. A b. A and B c. B and C d. C and D e. D and E

3 Nitrification is indicated by the letter(s) _____. a. A b. B c. B and C d. B and E e. D and E

4 Denitrifying bacteria convert _____ to _____. a. ammonium. . . nitrogen gas b. nitrates. . . nitrogen gas c. nitrogen gas. . . ammonium d. nitrogen gas. . . nitrates e. nitrogen gas. . . nitrites

5 Nitrifying bacteria convert _____ to _____. a. nitrogen gas. . . ammonium b. nitrogen gas. . . nitrates c. ammonium. . . nitrites d. nitrates. . . nitrogen gas e. ammonium. . . nitrogen gas

6 _____ removes nitrogen from the atmosphere. a. Denitrification b. Nitrification c. Mineralization d. Nitrogen fixation e. Assimilation

7 Which one of these is a nitrate? a. NO 2– b. NH 4– c. NH 2 d. SH e. NO 3–

8 Which one of these is a nitrite? a. NO 2– b. NH 4– c. NH 2 d. PO 4– e. NO 3–

9 Most plants acquire their nitrogen mainly in the form of. . . a. NH 3 b. N 2 c. CN 2 H 2 d. NO 3 e. amino acids absorbed from the soil.

10 The enzyme nitrogenase is inhibited by oxygen. Which one of the following has evolved specifically to avoid such inhibition? a. leghemoglobin b. root nodules c. water ferns d. carbohydrate transfer from hosts e. bacteroids

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KUNCI JAWABAN 1. A 2. E 3. B 4. B 5. C 6. D 7. E 8. A 9. D 10. A