NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
OCTOBER/NOVEMBER 2014 EXAMINATION

COURSE CODE:                                                                              BIO304

COURSE TITLE:                                                                             General Ecology

DURATION:                                                                                     2 Hours

INSTRUCTIONS:                                                                            Answer question 1 and any other 3 questions

Q1.       (a)       Account for the effect of industrialization on global warming.                             (7marks)

(b) Give a detailed explanation of why humans are considered to be initiators of secondary succession.                                                (8 marks)

            (c)       Describe the following attributes of populations:                                                                                    

(i)        Population size

(ii)       Population growth                                                                                        (10 marks)

Q2.       (a)       Define biogeochemical cycle.                                                                                    (3 marks)

            (b)       Write short notes on the following:

(i)        Energy flow                                                                                                    (4 marks)

(ii)       Efficiency of energy transfer                                                                        (4 marks)

(iii)      Denitrification                                                                                                (4 marks)

Q3.       (a)       How is carbon cycle different from other nutrient cycles?                                   (2 marks)

            (b)       With the help of a well labeled illustration, describe the carbon cycle.                          (13 marks)

Q4.       Distinguish between the following:

(i)        A habitat and a niche                                                                                     (3 marks)

(ii)       Pyramid of numbers and pyramid of energy                                             (3 marks)

(iii)      Gross primary productivity and net primary productivity                      (3 marks)

(iv)      Food chain and food web                                                                             (3 marks)

(v)       density-dependent and density-independent factors of population regulation                                                   (3 marks)

Q5(a) Compare the tropical rain forest and the savanna in terms of rainfall, animal types, vegetation and burning by fire.                                                                                      (8 marks)

            (b) Describe briefly the structure of communities.                                                           (7 marks)

Q6 Enumerate the world’s major environmental problems and suggest how they could be tackled.                                              (15 marks)