Study specimens L, M, N, P, Q, R and S carefully and use them to answer questions 4(a) to 4(d). (a) Name two specimens which can be used for the following: ...

(a) Two specimens for each function

• (i) Reproduction: specimen P (Irish potato) and specimen R (cassava cutting) [also Q, the Hibiscus twig].
• (ii) Protection: specimen L (goat skin) and specimen N (snail shell) [also M, the feather].
• (iii) Movement: specimen M (quill feather) and specimen S (hind wing of cockroach).

(b) Observable feature and reason for each choice

Reproduction:

• P (Irish potato): bears buds (eyes) that sprout to produce new shoots.
• Q (Hibiscus twig): bears buds that sprout to form new plants.
• R (cassava cutting): bears nodes with buds that sprout to produce new shoots.

Protection:

• L (goat skin): a hairy, sheet-like covering that protects the body against mechanical injury.
• M (feather): broad and smooth, it covers the body, prevents wetting and provides insulation.
• N (snail shell): hard and calcareous, it protects the soft body of the snail.

Movement:

• M (feather): the wing and tail feathers are flat and air-tight, providing surface for flight.
• S (cockroach hind wing): light and flexible, providing surface for flight.

(c)(i) Two similarities between P and R

• Both are modified stems.
• Both bear buds used for vegetative reproduction (and both possess lenticels).

(c)(ii) Two differences between P and R

(d)(i) How features of specimen M (feather) adapt it to its function: the vane is broad and stiff, giving a large air-tight surface that withstands air pressure and provides lift during flight; the barbs are interlocked by barbules to keep the vane firm; and the quill (calamus) is light, hollow and waterproof, giving buoyancy and keeping the bird dry.

(d)(ii) Increasing order of complexity of specimens L, M, N and S: S (cockroach) → N (snail) → M (bird) → L (goat/mammal).