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 Biology Paper 3,Nov/Dec 2008
 Questions: 1 2 3 Main
Weakness/Remedies
Strength

Question 2

(a)        Use the diagram below to answer questions 2(a)(i) to 2(a)(viii).

1. Identify the organism in the diagram without reasons.                      [1 mark]

(ii)        State five observable features that adapt the organism to its habitat. [5marks]
(iii)       What is the sex of the organism?                                                           [1 mark]
(iv)       Give three reasons for your answer in 2(a)(iii) above.              [3 marks]
(v)        Name the class to which the organism belongs.                          [1mark]
(vi)       State one observable feature characteristic of the class.             [1 mark]
(vii)     Name one other member of this class.                                       [1 mark]
(viii)      State two behavioural adaptations of the organism to its habitat. [2marks]

(b)        Study the diagrams below and use them to answer questions 2(b) (i) to 2(b)(iv)

(i)Identify the structures in the diagrams without giving reasons.       [2 marks]
(ii)        Name the parts labelled I to VIII.                                                       [4 marks]
(iii)       Names the bones that articulate with I, IV and V.                                [3 marks]
(iv)       State one function of the part labelled III.                                           [1 mark]

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OBSERVATION

This question was the most popular question among the candidates and they were able to score pass marks.  Most of the candidates correctly identified the specimen as an Agama lizard.  Some candidates used the scientific name Agama agama but did not start with a capital letter and did not underline as is conventionally required and so lost the mark.

Most candidates could state the observable features of the lizard but could not state how they adapt the organism to its habitat and so lost marks.  Expected answers include:

-           Presence of scales to prevent desiccation/drying;
-           Possession of claws on digits for climbing/grasping;
-           Bulging eyes for wide view;
-           Wide mouth for feeding;
-           Long tail for territorial defence/balancing;
-           Presence of tympanic membrane sensitive to sound vibrations/to hearing;
-           Well developed limbs for movement on land/landing;
-           Nostrils for gaseous exchange

Most candidates correctly identified the lizard as a female but only a few candidates could give reasons namely.

-           Absence of gular fold;
-           Absence of nuchal crest;
-           Patches on side of body.

Many candidates could state the class to which the lizard belongs, state one observable feature of the class as well as give other examples of members of the class but some candidates lost marks due to spelling errors.

Most candidates however could not state behavioural adaptations of the lizard.

1. Bask in early morning sun to raise the body temperature;
2. Camouflage or blend with its environment;
3. Display of colour by male to ward off intruders;
4. Bury eggs in the soil for protection and warmth.

In part (b), many candidates could not identify the scapula but could correctly identify the pelvic girdle but most of them lost marks due to spelling errors e.g. Scapula was spelt as scapila etc.

Most candidates could not correctly name the labelled parts or state the articulating bones of I, IV and V or state the function of the part labelled III/the blade of the scapula.

Naming of parts
I    -    Glenoid cavity;                           V      -    acetabulum
II   -    spine                                         VI     -    obturator foramen;
III  -    blade;                                       VII    -    ischium;
IV  -    ilium;                                         VIII   -    pubis.

Articulating bones
I      -     articulates with the (head) of humerus
IV   -   articulates with the sacrum
V   -     articulates with the (head) of femur