Answer all the questions in this section.
Study specimen S, T, U, V and Wand answer questions 4 (a) to 4(e).
(a) (i) Name the habitats of each of specimens S, U and W.
(ii) Name the class to which each of specimens S, U and W belong.
(b) State: (i) Four observable similarities between specimens S and U. (ii) five observable differences between specimens S and U.
(c)(i) identify the sex of specimen U. (i) State two reasons for the answer in 4 (c)(i).
(d)State four observable features that adapt specimen S to its habitat.
(e) Construct a food chain using at least three of the given specimens.
Explanation
(a)(i) Habitats of Specimen S/Toad, U/Lizard and W/Locust:
Specimen S: Wet/moist/damp land/under stone/damp grass/vegetation near freshwater ponds.
Specimen U: House/walls/cracks/mountain slopes/trees/garden/farmland
Specimen W: Vegetation/grassland/farm/trees/leaves
(ii) Class to which Specimens S, U and W belong:
Specimen S: Amphibia
Specimen U: Reptilia
Specimen W: Insecta
(b)(i) Observable similarities in Specimens S and U:
Both have: -eyes, head,
(wide terminal) mouth,
2 pairs/4limbs/forelimb/hind limb,
tympanic membrane/eardrum,
nostrils, trunk.
Observable differences between Specimens S and U:
(ii) - Specimen S/Toad has poison gland but poison gland is absent in Specimen U/Lizard
-Gular fold absent in Specimen S/Toad but Gular fold is present in Specimen U/Lizard
- Presence of bulging eyes in Speciemen S/Toad, eyes are not bulging in Specimen U/Lizard
- Scales absent in Specimen S/Toad but scales present in Specimen U/Lizard
-Streamlined body in Specimen S/Toad, body not streamlined in Specimen U/Lizard
- Warty skin on Specimen S/Toad but no warts on Specimen U/Lizard
- Absence of tail in Specimen S/Toad but tail is present in Specimen U/Lizard
- Absence of nuchal crest in Specimen S/Toad but nuchal crest is present in Specimen U/Lizard
- Neck absent in Specimen S/Toad but present in Specimen U/Lizard
- Digits of hind limbs of Specimen S/Toad are webbed, but not webbed in Specimen U/Lizard
- No claws on the digits of Specimen S/Toad but digits of Specimen U /Lizard end in claws
- In Specimen S/Toad the forelimbs end in four digits, but in Specimen U/Lizard the forelimbs end in five digits
-Body is short and wide in Specimen S/Toad but long and narrow in Specimen U/Lizard.
(c)(i) Sex of Specimen U: Male.
(ii)Reasons for the answer in 4(c(i):
-Brightly colored with red head/blue black trunk;
- Blue and orange tail; Presence of Gular fold
-Prominent Nuchal crest
- Presence of hemi-penis
(d) Observable features that adapt Specimen S to its habitat
- Poison gland; for protection;
- Warty skin; for camouflage
-Webbed digits of hind limbs for swimming;
- Bulging eyes; for wide vision;
- Muscular forelimbs; for absorbing shock
- Long muscular hind limbs for jumping/hopping
-Cryptic coloration for camouflage;
- Moist skin for (cutaneous) respiration;
-Forelimbs have pads for absorbing shock during landing.
(e) Food chain:
Specimen T/grass => Specimen W/Locust => Specimen S/Toad
Specimen T/grass => Specimen W/Locust => Specimen U/Lizard