Observation

 

Some candidates could name the labelled parts but lost marks to poor spellings of the names.
The candidates that stated the adaptation of the part labelled III could not state the feature with its function. Some only stated the function which made them lose one mark.

Some candidates displayed their ignorance of the structure of a grasshopper by not placing the listed structures in their appropriate positions on the incomplete grasshopper in the diagram.

Majority of the candidates were able to state the economic importance of grasshopper to its ecosystem and humans.

Some candidates could not classify the grasshopper into its phylum and class, neither could they give the reason for the classification. A few that could, lost marks to poor spellings.

 

The expected answers are:

1. (a)  (i) Name of labelled parts

 

I. Elytron/forewing/wing; 

                         

II. Abdomen/abdominal segment;

                           

III. (Walking) leg;

IV. Pronotum/thorax/scutellum. 

    

(ii) Adaptation of the part labelled III to its function

• It is short; for safe landing;
• Presence of claws at its tips; to grip vegetation/for firm grip/for stability;
• Claws; for crawling/movement

.                     

Note:   Feature of the structure and function must correspond to score 2 marks;
            Feature alone can score 1 mark;
            Function alone does not score.

 

(b) Complete drawing of the illustrated drawing

 

 

 

Details
Compound eye (big 1/3  of the head) - (CE)
Hind leg (large and long) - (LL);
Mouthparts (properly shown) - (MP);
Antennae (Short and segmented) – (AN).

Note: 1 mark for correct position of each part.

Quality
Clarity of lines (CL)              
Ruled guideline (RG)            
Horizontal labels (HL)                                                                       

 

(c)        Ways by which the organism is of importance to

            (i) its ecosystem

 

• Destroys vegetation;
• Breathes out carbon dioxide which plants use for photosynthesis;
• Serves as food for other organisms;
• Causes discomfort/nuisance.                                            

 

(ii) humans

 

• Serves as food/feeds for poultry;
• Destroys crops;
• Serves as specimen for scientific research;
• Reduces crop yield;
• Provides income.                                                              

 

Phylum
      Arthropoda  

 

(ii) Class
     Insecta 

 

Reasons for classification

 (i) Phylum

 

• Jointed appendages;
• Chitinous exoskeleton covers body;
• Body bilaterally symmetrical;
• Body metamerically segmented

 

(ii) Class

 

• Body is divided into head, thorax and abdomen/three body divisions;
• Thorax bears three pairs of legs;
• A pair of wings;
• A pair of compound eyes;
• A pair of antennae.