Past Questions and Answers on Population Ecology

SSCE/WASSCE/GCE PAST QUESTIONS AND ANSWERS

OBJECTIVES

1.      In a savanna ecosystem the abiotic factors include
A. legumes, temperature and sandy soil
B. water, temperature and soil
C. minerals, oxygen and reptiles
D. water, soil and grasses

Use the diagram below to answer question 2 & 3




2.      Which of the following is an omnivore
A. Praying mantis      
B. Hawk           
C. Mouse            
D. Grasshopper

3.      Which of the organisms will have the lowest population in an ecosystem?
A. Hawk                   
B. Cowpea      
C. Praying mantis          
D. Mouse

4.      A population with a relatively large proportion of adults will
A. be crowded         
B. decline         
C. expand         
D. remain stationary

5.      Which of these is NOT an adaptive feature for arboreal life?
A. Possession of long tail
B. Possession of claws
C. Possession of teeths
D. counter shading in coat colour

6.      Which of the following is true of climax community?
A. it persists until the environment or climate changes
B. it changes drastically from one year to the next
C. it is first stage in succession
D. It is made up of the tallest trees and the smallest

7.      Mutualism is exhibited by
A. tapeworm living in the gut of man
B. yellow dodder growing on milk bush
C. platycerium growing on a palm tree
D. rhizobium living in the root nodule of groundnut

8.      Which of the following factors is LEAST likely to affect the animals living in a fresh water habitat?
A. Turbidity                  
B. Temperature      
C. pH       
D. Salinity

9.      Which group of plants would be the first colonizers in an ecological succession changing rocks to soil?
A. Mosses             
B. Ferns            
C. Lichens     
D. Grasses

10.      Colonization of a bare rock surface is termed
A. evolution     
B. specification         
C. primary succession        
D. secondary succession

11.  Toads and lizards in an ecosystem depend on a limited quantity of food. This is an example of
A. parasitism
B. intraspecific competition
C. predation
D. interspecific competition

12.  Adaptive features of plants to desert conditions include
A. thick barks, succulent stems and sunken stomata
B. thin barks, succulent stems and sunken stomata
C. thin barks, air floats on stems and sunken stomata
D. air spaces in tissues, adventitious roots and thick barks

13.  The Southern Guinea Savanna in that it has
A. lower rainfall and shorter grasses
B. less grasses and scattered trees
C. more rainfall and taller grasses
D. less arboreal and burrowing animals

14.  The association between a fern and a palm trees on which it is growing is an example of
A. epiphytism          
B. mutualism
C. parasitism           
D. saprophytism

15.  A fresh water plant such as water lily can solve the problem of buoyancy b the possession of
A. aerenchymarous tissues
B. dissected leaves
C. thin cell walls of the epidermis
D. water-repelling epidermis

16.    The least adaptive feature of aboreal life is the
A. possession of fouur limbs
B. possession of claws
C. development of long tail
D. shading of coat colour

17.    The most important environmental factor which epiphytes in the rain forest compete for is
A. water                   
B. nutrient         
C. light      
D. space

18.    An ecological succession often leads to
A. an increase in species diversity
B. decrease in species diversity
C. an unstable community
D. the dispersal of species

19.    I. High birth rate and high immigration rate 
II. Low birth rate and high immigration rate
III. Low mortality rate and low emigration
IV. High mortality rate and high emigration rate. 
Which combination of the above can cause rapid over-crowding in climax biotic communities and human settlements?
A. II and III                
B. I and III            
C. I and IV       
D. I and II

20.    Which of the following are adaptations of animals to aquatic habitats?
A. Gills, streamlined bodies and lateral lines
B. Lateral line, streamlined bodies and lungs
C. Gills, scaly skin and lungs
D. Gills, streamlined bodies and spiracles

21.    Which of the following is an adaptation of forest species?
A. Few stomata       
B. Thick bark        
C. Buttress roots      
D. Reduced leaves

22.    Which of the following structural features are adapted for uses other than water conservation?
A. Succulent stems    
B. Scales in animals  
C. Spines in plants
D. Feathers in bird

23.    An association between the root nodule of a leguminous plants rhizobium sp, is known as
A. commensalism      
B. mycorrhiza           
C. parastism       
D. symbiosis

24.    The number of plants species obtained from a population study of a garden is as follows: Guinea grass (15), Ipomea spp (5), sida spp (7) and Imperata spp (23). What is the percentage of occurrence of Imperata spp?
A. 35%     
B. 16%     
C. 46%      
D. 23%

25.    The epiphytic habitat can best be described as
A. arboreal               
B. estuarine        
C. aquatic     
D. terrestrial

26.  In a population study using the transect method, a student is likely to record the highest number of species in
A. a tropical rain forest
B. a guinea savanna
C. a sahel savanna
D. an estuarine swamp

27.    A freshwater pond may contain
A. tadpole, water boatman, leeches and crab
B. water beetle, shrimps, water snail and water bug
C. water lily, fish, water scorpion and dragon larva
D. pon skater, water lily, shark and mosquito larva

28.    The distribution of plants in a rain forest is governed mainly by
A. vegetation        
B. soil types    
C. amount of sunlight     
D. rainfall pattern

29.    The stem of a typical aqautic plant usually has many
A. air cavities
B. intercellular space
C. water cavities
D. water conducting cells

30.    The ability of an organism to live successfully in an environment is known as
A. resistance              
B. competition      
C. succession     
D. adaptation

Answers

1. B

7. D

13. C

19. B

25. A

2. C

8. D

14. A

20. A

26. A

3. A

9. C

15. A

21. C

27. C

4. C

10. C

16. D

22. A

28. D

5. C

11. D

17. B

23. D

29. A

6. A

12. A

18. A

24. C

30. D

THEORY

1.    (SSCE, 1997) (b) State four structural features which adapt animal to a named natural habitat

(c) Describe the method you would use to determine the density of a named plant species in a terrestrial habitat.

Solution
(b) A named natural habitat can be terrestrial, aquatic or arboreal.

Some structural features which adapt animals to aquatic habitat are:

1. Possession of gills for gaseous exchange

2. Possession of swim bladder for buoyancy

3. Streamlined shape for easy movement

4. Lateral line for detection of vibration

5. Fin for movements

6. Slimy body for easy movement

7. Sucker for attachment onto vegetation

(c) The density of the plant to be determined is Tridax. The area to be surveyed id determined and a quadrat is thrown severally at random. Where ever the quadrat lands, the number of individual plants species present is counted. Plants partially enclosed are counted as half. The density is calculated by dividing the total number of times the species occurs within the quadrat by the total area of the quadrat.


2.      (SSCE, 2006 Q3) (a) Define the term adaptation.

(b) Describe how plants are adapted to the following habitat giving one example for each habitat:

(i) Dry terrestrial habitat

(ii) Fresh water habitat


Solution

Refer to blog Content


3.      (WASSCE, 2007 Q3) (b) Briefly describe how the crab is adapted for life in its habitat.

(c) List

(i) four causes of food shortage

(ii) four factors that affect population size.


Solution

Adaptation of crab to habitat
1. Burrows and stays in burrows
2. Presence of exoskeleton to prevent desiccation
3. Possession of gills for oxygen intake in water
4. Presence of powerful chelipeds for seizing food
5. Body fluid is isotonic with sea water to prevent loss of body fluids by osmosis
6. Possession of lung-like tissue for absorption of atmospheric oxygen.

(c) (i) Causes of food shortage 
1. Drought                     
2. Bush fire  
3. Overpopulation         
4. Erosion
5. Infertility of soil         
6. Plant diseases  
7. lack of mechanized farming methods
8. poor food preservation methods
9. poor transportation of agricultural goods

(ii) Refer to blog Content