Biology Paper 3 (Practical), WASSCE (SC), 2016

Question 2

     

    Study specimens H, K, L and Mcarefully and use them to answer

                            questions 2(a) to 2(e).

     

    1. Name the location of each of specimens H, K and M in the body of a mammal.                                                                                                                             [3 marks]

                            (b) (i)   Name the fluid in specimen L .                                                           [1 mark]

                                 (ii)   State two functions of the fluid named in 2(b)(i).                              [2 marks]

                                 (iii) Which of the other specimens is specimen L associated with?         [1 mark]

         (c)  (i) State two observable differences between specimens H and K.        [2 marks]

                (ii) State two observable features of specimen K that adapt it to its function.

    [4 marks]

          (d) State one biological importance each of specimens K and M.           [2 marks]

    (e) Make a drawing, 8cm-10cm long of specimen M and label fully.           [10 marks]

     

Observation

Many candidates could not name the location of specimens H (fresh liver), K (fresh lung) and M (fresh kidney) in the body of a mammal correctly. Some of the few that got the correct location missed the mark to poor spellings.

Some candidates could not name the fluid in specimen L (gall bladder) but state the functions of the bile. Majority of the candidates could state that specimen L (gall bladder) is associated with specimen H (fresh liver).

Only a few candidates were able to state the observable differences between specimens H (fresh liver) and K (fresh lung).  A few candidates were able to state the features that adapt specimen K (fresh lung) to its function.

 

 

 

Question 2(d) was well answered.0

Many candidates did not draw specimen M (longitudinal section of kidney) to specifications; some diagrams were not bean-shaped; the three regions not shown; and the magnification of the drawing was not written.

           

The expected answers include:       

           

  • (a)     Location of specimens H, K and M in the body of a mammal

Specimen H/Liver: Below the diaphragm/ upper part of abdominal cavity/abdomen;

Specimen K/Lung: Thoracic cavity/chest/thorax/thoracic region;

Specimen M/Kidney: located at the dorsal wall of the abdominal cavity/abdomen.

 

   (b) (i) Fluid in specimen L

Bile.                                                                                                                 

        (ii) Functions of the fluid in specimen L

  • - It emulsifies fats (and oils into fat droplets);
  • - The inorganic salts in it neutralize the acid in the chyme/bile neutralizes chime;
  • - It provides alkaline medium for pancreatic juice to act;
  • - It prevents the decay of food in the small intestine.                                

 

        (iii) Other Specimen that Specimen L is associated with

            Specimen H/Liver.                                                                                         

 

(c) (i) Observable differences between Specimens H/Liver and K/Lung

  • - Specimen H/Liver is more solid/thick/turgid while Specimen K/Lung is soft/softer/fluffy;
  • - Specimen H/Liver is darker/ dark red in colour while Specimen K/Lung is brighter/red/pink in colour;
  • - Specimen H/Liver is smoother on the surface while Specimen K/Lung is folded/convoluted surface.                                                                                                       

(ii) Observable features that adapt Specimen K/Lung to its function

  • - Moist/wet surface; for dissolving gases/O2/CO2;
  • - Thin surface membrane for easy diffusion/exchange of gases;
  • - Many blood vessels/highly vascularised/for transportation of gases/dissolved food substances.

NB: Structure and function must correspond to score.


Title (TL)                                                                               

Quality (Q)

Clarity of lines (CL)                                      

Neatness of labels (NL)                                 

Correct Size (SZ) 8cm-10cm                         

Magnification (Mg)    (x1 - 1½)        

           

Details (D)

            Bean shaped kidney (BS)                              

Three regions shown (TR)                             

 

Labels (L)

Cortex; Medulla/Pyramid/Medulla Pyramid; Pelvis/Renal Pelvis; Ureter; Renal artery; Renal vein; Hilus; Capsule.