Observation

This question was the most popular question attempted by candidates. Many candidates performed well in this question although some candidates lost marks to spelling mistakes and inability to express their points coherently e.g. some candidates wrote hydro skeleton instead of hydrostatic skeleton and ectoskeleton was written instead of exoskeleton.

Many candidates were able to state the functions of the skeleton properly where they mainly got good marks.

Majority of candidates that lost marks lost them in (d). Some drew the axis instead of atlas while some others just drew a vertebra of their choice. The requirements for diagrams were not met by many candidates as they did not put title; they used wooly line for the labels or the guideline not touching the label. Some did not draw to the correct specification.

The expected answers are:

(a) (a) Skeleton
Is the solid framework; consisting of system of bones and joints; supporting/protecting/allowing movement of the body; upon which other body structures are held together/attached/built.                                                                 

(b) Type of skeleton and examples of organisms that possess the skeleton

NB: Spellings must be correct to score

(c) Functions of the mammalian skeleton

• Provides support;
• Protects the delicate parts of the body;
• Stores some mineral salts needed by the body;
• Provides attachment surfaces for muscles of the body; enhance movement/for movement;
• Makes red blood cells and some white blood cells;                     
• Forms framework of the body;
• Gives shape;
• Supports in breathing.                                                                  

(d) Diagram of the anterior view of atlas vertebra

Quality (Q)
Clarity of lines      (CL)                                                                           
Size           (SZ)     (6 cm to 8 cm) (Across the cervical vertebra)           
Neatness of labels             (NL)                                                               

Details (D)
Vertebrarterial canals shown (VC)                                                          
Reduced neural spine (NS)                                                                      
Cervical rib/transverse process shown (CR/TP)                                                  

Labels (L)
Neural spine; vertebrarterial canal; transverse process/cervical rib; neural canal; neural arch; facets; odontoid fossa/cavity.