NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF EDUCATION
JANUARY 2018 EXAMINATION

COURSE CODE SED 421

CODE TITLE:  CYCLES IN NATURE – BIOLOGICAL CYCLES

CREDIT UNIT:            2

Time: 2  hours

INSTRUCTION:  ANSWER QUESTION ONE AND THREE OTHER QUESTIONS. QUESTION ONE IS COMPULSORY

Question 1

1. Explain the four major transformations that atmospheric Nitrogen can undergo. (12 Marks)
2. State at least two (2) human activities that have significant impact on the Nitrogen cycle. (2 Marks)
3. List and discuss at least five (5) human activities that alter the Water cycle. (5 Marks)
4. Briefly discuss the essential features of the arid climate. (6 Marks)

 25marks

Question 2

1. Briefly explain the Carbon cycle. (10 Marks)
2. Discuss at least three (3) human activities that lead to increase of Carbon dioxide in the atmosphere. (3 Marks)
3. Give two (2) reasons why it is important for one to know his/her biorhythm cycle. (2 Marks)

                                                                                                                          15marks                              

Question 3

1. What is Atmospheric Chemistry? (3 Marks)
2. Explain the three (3) central elements in Atmospheric Chemistry. (9 Marks)
3. List the main features of Plate tectonics. (3 Marks)

                                                                                                                              15marks

Question 4

1. Explain the meaning of Karst (2 Marks)
2. Briefly discuss the Karst cycle of erosion (9 Marks)
3. List the conditions necessary for full development of Karst topography (4 Marks)

                                                                                                                              15marks

Question 5

1. Briefly explain what you understand by Ocean Waves (2 Marks)
2. List the various classes of Ocean currents. (3 Marks)
3. Describe the materials used for the manufacture of Canoe . (10 Marks)

                                                                                                                              15marks