Question

2. Study specimens F, G and H and answer questions 2(a) to 2(f).
(a) Name the Class to which each of specimens F and G belong.
(b) State one reason each for the answers in 2(a).
(c) Name the root system of each of specimens F and G.
(d)(i) Detach one complete leaf from specimen F and make a drawing, 8cm to 10cm long of the leaf and label fully.
(d)(ii) State one function each of three of the labelled parts of the drawing in 2(a)(1).
(e) State three ways by which specimen F is of economic importance.
(f)(i) Describe briefly four observable features of specimen H.
(f)(ii) State one biological significance of specimen H to the plant from which it was obtained.

Accepted Answer

(a) Class: F: Monocotyledoneae/Monocotyledonae/Liliopsida (e.g. Guinea grass/Panicum sp.); G: Monocotyledoneae/Monocotyledonae/Liliopsida (e.g. Cocoyam/Caladium sp.).

(b) Reasons: F — leaves have parallel venation; leaf sheath present; presence of fibrous root system; narrow leaves/leaves with narrow lamina; circular node present. G — presence of fibrous/adventitious/contractile root system; bears tiny axillary bud at some points of the nodes; bears tiny, broad terminal buds; surrounded with relatively large scale leaves; presence of long adventitious roots.

(c) Root systems: F — Fibrous; G — Adventitious/contractile/fibrous.

(d)(i) Drawing of the complete leaf of specimen F (Guinea grass/Panicum sp.) should show and label: Apex, Margin, Midrib, Blade, Vein, Ligule, Leaf sheath. (Title, Quality — clarity of lines, size 8-10cm, neatness of labels, magnification — should all be indicated; drawn 'Not Drawn to Scale'.)
(ii) Functions of three labelled parts: Lamina/leaf blade — photosynthesizes to make food for the plant/site for gaseous exchange. Leaf sheath — supports the lamina/attaches the lamina to the stem. Vein — contains xylem which conducts water and mineral salts through the leaf/contains phloem to transport manufactured food out of the leaf/gives structural support to the leaf/contains supporting tissues. (Other parts: Leaf ligule — allows movement of the lamina. Apex — allows water drop off the leaf/prevents water retention. Midrib — supports the blade.)

(e) Economic importance of specimen F (Guinea grass/Panicum sp.): used as feed/fodder for cattle; used as fuel; for roofing houses/structures; for making baskets; has medicinal purposes; used as rope; used for mulching; for generating income.

(f)(i) Observable features of specimen H (corm of cocoyam): vertical/swollen stem; brown in colour; bears concentric rings of nodes; bears tiny brown scale leaves at some points of the nodes.
(ii) Biological significance of specimen H to the plant: Vegetative propagation/storage of food/for anchorage.

WAEC Biology 2023 Theory — Question 10

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