2018 WAEC Biology Theory Diagrams D, E and F are illustrations of tools used for ecological studies. Study them…

Biology WAEC 2018

Diagrams D, E and F are illustrations of tools used for ecological studies. Study them and answer questions (a) to (c).

 

(a)(i) Identify diagrams D, E and F.                  

  1. Name the parts labeled I to VIII.                    
  2. State one function each of the parts labeled I, III, IV, V and VII.                  

(b) State one use each of the tools labeled D, E and F.                   
(c)  Describe briefly the use of each of the tools labeled D, E and F.  

Explanation

 

(a) (i)   Identification of diagrams D, E and F

D – Sweep net/butterfly net/ insect net/ hand net;
E – Pooter;
F – Quadrat.                                                                                       

      (ii) Names of labeled parts

I- Handle (of Sweep net/butterfly net);      V- Specimen container/tube;

II- Net;                              VI- Collecting/ tube;

III- Suction tube;                        VII- Frame;

IV- Wire mesh/gauze/cotton;              VIII- Thin wire/string

.                                                                                                   
(iii) Function of parts labeled I, III, IV, V and VII
I - Handle of Sweep net/butterfly net: for holding the instrument in place for use; 
III - Suction tube: to apply suction pressure to draw in the insect;               
IV - Wire mesh/gauze/cotton/sieve: prevents the insect /dirt from entering the/suction tube/ 
        mouth;
V - Specimen container/tube; for keeping the sucked insect (temporarily);  
VII - Frame; to demarcate the area of study/ sample area.         

 (b) Use of tools labeled D, E and F
D - Sweep net/butterfly net: to catch flying insects
E - Pooter: to collect tiny invertebrates from leaves /litter/crevices
F - Quadrat: to determine the population of small, slow-crawling organisms/ small plants within  the restricted area                                           

  (c) Description of use of
(i) D/Sweep net/butterfly net

  • the handle of the net is swung towards the organisms when sighted;
  • when the organisms are caught;
  •  the middle part of the net is held closed to prevent the escape of the organisms.                                                                                                      

       (ii) E/Pooter

  • the collecting tube is pointed to the organism when sighted;
  • And the suction tube is placed in the mouth and sucked;
  • The insect is drawn into the specimen tube/container.        

      (iii) F/Quadrat

  • The quadrat is thrown randomly;
  • Wherever the quadrat lands, the number of selected/targeted/determined species enclosed within the quadrat is counted;
  • The number is recorded. /;
  • This procedure is repeated several times/ at least ten times;
  • Average number of species per throw/toss is calculated;
  • The frequency/ total number/ density / percentage covered is then determined.
Previous Question Next Question

Leave A Comment