WAEC SSCE - Biology - 2014 (Practical)

(a)(i) Habitats

• L (grass): grassland, farmland or garden.
• M (grasshopper): grassland, farmland, garden or field.
• N (saprophytic fungus): moist or damp soil, decaying wood, decaying tree trunks, pastures or meadows.

(a)(ii) Modes of nutrition

• L: autotrophic, holophytic or photosynthetic nutrition.
• M: heterotrophic, holozoic nutrition.
• N: saprophytic nutrition.

(a)(iii) Adaptations to feeding

• Specimen L: It has broad green leaves containing chlorophyll for trapping sunlight during photosynthesis. Its roots absorb water and mineral salts needed for food manufacture.
• Specimen M: It possesses strong biting and chewing mouthparts, especially the mandibles and maxillae, for cutting and chewing grass and other plant materials.

(b)(i) Relationship among L, M and N

Specimen L is a producer and provides food, as well as shelter, for specimen M. Specimen M feeds on specimen L. When L and M die, specimen N decomposes their remains. The decomposition releases mineral nutrients into the soil for use by L. Thus, the specimens are linked in a food chain and nutrient cycle.

(b)(ii) Economic importance of specimen M

1. It is edible and may serve as a source of food and income.
2. It is a crop pest that destroys plants and reduces crop yield.

(b)(iii) Control of specimen M

Control it by spraying the affected crops with a suitable insecticide or pesticide.

(c) Labelled drawing of specimen M

Title: Grasshopper

A full lateral-view drawing, 8 cm to 10 cm long, carries the following labels: antenna, compound eye, head, mandible, thorax, fore wing (tegmen), hind wing, fore leg, middle leg, enlarged hind femur, hind tibia, tarsus, spiracles, segmented abdomen and ovipositor.

(a)(i) Specimen A is classified as follows:

• Division: Angiospermophyta (Magnoliophyta)
• Class: Monocotyledoneae (Liliopsida)

(a)(ii) Observable features of A which are characteristic of monocotyledons are:

1. It has narrow, elongated leaves.
2. The leaves have parallel venation.
3. It has fibrous roots.
4. The base of each leaf forms a sheath around the stem.

(b)

1. Specimen B is the male flower or male inflorescence (tassel) of specimen A.
2. Specimen C is the female flower or female inflorescence (cob) of specimen A.
3. Specimen D is the fruit, also called the grain or seed, of specimen A.

(c)(i) Specimen A is a monoecious plant.

(c)(ii) The agent of pollination of specimen B is wind.

(c)(iii) This is because the male inflorescence (B) and female inflorescence (C) are separate, but both occur on the same maize plant.

(d) Specimen D is a true, simple, dry, indehiscent fruit known as a caryopsis. Its pericarp is fused with the seed coat.

(e) Labelled drawing of specimen C, the female maize inflorescence (cob):