TEST OF PRACTICAL KNOWLEDGE QUESTION (a) Study specimens E and F carefully and use them to answer questions 2(a)(i) to 2(a)(ii). (i) State the Class to whic...

Answer Details

(a)(i) Class of each specimen: Specimen E belongs to Class Mammalia; Specimen F belongs to Class Aves.

(a)(ii) Four observable features of each

Specimen E (rat): body covered with fur/hair; external ears (pinna); presence of whiskers; heterodont dentition; pentadactyl limbs ending in claws; mammary glands. Specimen F (bird): body covered with feathers; mouth modified into a beak; fore-limbs modified into wings; legs covered with horny scales; a streamlined body.

(a)(iii) How the features adapt each specimen to its habitat

Specimen E: the enlarged pinna traps sound waves; whiskers detect vibrations and help it feel its way through burrows; the narrow body with folded limbs eases movement through burrows; the long muscular hind limbs allow hopping; sharp incisors (heterodont dentition) nibble vegetation; clawed limbs are used for digging; the fur regulates body temperature. Specimen F: the fore-limbs modified into wings enable flight; the streamlined body reduces resistance during flight; the feathers regulate body temperature and the tail feathers steer and balance the body; the beak is adapted for feeding; the clawed digits scratch for food; and the laterally placed eyes give a wide field of vision.

(b)(i) Classification of Specimen G: Phylum Arthropoda, Class Insecta.

(b)(ii) Four observable features of Specimen G (mud-dauber wasp): the abdomen is constricted into a narrow waist; two pairs of membranous wings with the fore-wings larger than the hind-wings and linked by hooklets; the body has three divisions (head, thorax and abdomen) and is segmented and bilaterally symmetrical; three pairs of jointed thoracic legs; a pair of antennae; a pair of compound eyes; and an exoskeleton of chitin.

(b)(iii) Habitat of Specimen G: a mud nest built on the ceiling or wall of buildings.