CARA'S TIPSPractical 4: flowers, fruits, dispersal, monocots and dicots, algae, fungi and protists
WAECNECO
What the syllabus asks
WAEC: plant and microorganism specimens: flowering plant, flower structure, pollination, fruits and placentation, dispersal, monocot vs dicot (seeds, roots, leaves), fern, moss, Spirogyra, Rhizopus, mushroom, Amoeba, Euglena, Paramecium; drawing.
NECO: plant and microorganism specimens: flowering plant, flower structure, pollination, fruits and placentation, dispersal, monocot vs dicot (seeds, roots, leaves), fern, moss, Spirogyra, Rhizopus, mushroom, Amoeba, Euglena, Paramecium; drawing.
What you will learn
- Describe flowering plant specimens with correct terms.
- Identify flower parts and floral types.
- Distinguish insect- and wind-pollinated flowers.
- Classify fruits and identify placentation.
- Relate fruit structure to dispersal.
- Distinguish monocots from dicots.
- Identify ferns, mosses, Spirogyra, fungi and protists and state their features.
- Draw plant specimens with correct labels and magnification.
Key points
- Flower parts: calyx, corolla, androecium, gynoecium.
- Insect vs wind pollination: petals, scent, stigma, pollen.
- Fruit types and placentation from L.S. and T.S.
- Dispersal agents with adaptive features.
- Monocot vs dicot: cotyledons, veins, roots, floral parts.
- Fern (sori, fronds) vs moss (rhizoids, capsule).
- Spirogyra, Rhizopus, mushroom, Amoeba, Euglena, Paramecium: key structures.
Start here: Plant and microorganism specimens
Botanical specimens are cheap and fresh, so they appear in every practical paper: whole plants (Guinea grass, cocoyam, Tridax, a seedling), flowers (Pride of Barbados, Hibiscus, Crotalaria), fruits (orange, coconut, tomato, okra, mango, pawpaw, groundnut, chilli pepper), seeds (bean, maize), and lower plants and fungi (fern, moss, Spirogyra, bread mould, mushroom). Microorganisms such as Amoeba, Euglena and Paramecium are shown as slides or pictures.
The flowering plant
A flowering plant has a root system (tap root or fibrous roots) and a shoot system (stem with nodes and internodes, leaves, buds, flowers and fruits). On a whole-plant specimen, look for: type of root; whether the stem is herbaceous or woody, erect or creeping; leaf arrangement (alternate, opposite, whorled); leaf type (simple or compound); venation (net or parallel); presence of a leaf sheath (grasses) or petiole; modifications such as tendrils, thorns, corms, rhizomes or tubers.
Plant specimens in the 2023 WAEC paper
The 2023 WAEC list included Pride of Barbados flower and leaf, Guinea grass, a cocoyam plant and its corm, orange, coconut and chilli pepper. Notice the pattern: a dicot and a monocot to compare, a stem tuber or corm (vegetative propagation), and fruits for placentation and dispersal. Prepare each specimen on your own school list in the same way.
Describing a leaf
| Feature | Terms to use |
|---|---|
| Lamina shape | linear (grass), ovate, lanceolate, cordate (heart-shaped, cocoyam), palmate |
| Margin | entire (smooth), serrate (toothed, Hibiscus), lobed |
| Apex | acute, acuminate, obtuse |
| Venation | reticulate (net, dicot) or parallel (monocot) |
| Type | simple (one blade) or compound: pinnate (Pride of Barbados is bipinnate), palmate (cassava leaf is deeply lobed, almost palmately divided) |
| Base | petiole present; sessile; leaf sheath (grass, maize) |
Write what you see: a cocoyam leaf is large, cordate (sagittate), net-veined with a long petiole and a sheathing base. A Guinea grass leaf is long, linear, parallel-veined with a leaf sheath wrapping the stem and a hairy ligule at the junction.
Storage organs and vegetative propagation
Underground storage organs are favourite specimens because they show both food storage and vegetative propagation. Learn to prove that each is a stem or a root.
| Organ | Example | Evidence |
|---|---|---|
| Corm | cocoyam, taro | short, swollen, upright stem with nodes, scale leaves and buds |
| Stem tuber | Irish potato, yam (a tuber of stem origin in most texts) | “eyes” are buds in the axils of scale leaves; sprouts from them |
| Rhizome | ginger, Guinea grass base, fern | horizontal underground stem with nodes, scale leaves, buds and adventitious roots |
| Bulb | onion | short flat stem (basal plate) with fleshy scale leaves and a terminal bud |
| Root tuber | sweet potato, cassava | swollen root; no nodes or scale leaves; buds only at the stem end |
To show starch storage, cut the organ and add a drop of iodine: a blue-black colour confirms starch. Farmers propagate cocoyam from corms and cormels, yam from setts (cut pieces of tuber), cassava from stem cuttings and sugar cane from stem cuttings with nodes. Vegetative propagation gives plants identical to the parent and quicker maturity, but spreads diseases (such as cassava mosaic virus) carried in the planting material.
Continue this lesson in the free app →
Practice questions
- filament
- style
- stigma
- receptacle
Show answer
A: filament
A stamen is an anther on a filament.
- stamen
- sepal
- receptacle
- carpel (pistil)
Show answer
D: carpel (pistil)
Stigma, style, ovary.
- feathery stigmas
- small, dull or no petals
- sticky or spiky pollen grains
- long, hanging stamens
Show answer
C: sticky or spiky pollen grains
Rough or sticky pollen clings to insects; the other features suit wind pollination.
- flamboyant (flame of the forest)
- maize
- hibiscus
- crotalaria
Show answer
B: maize
Maize has feathery stigmas (the silk) and light pollen carried by wind; the others have showy petals that attract insects or birds.
- ovary
- ovule
- stamen
- sepal
Show answer
A: ovary
Seeds develop from ovules.
Key words
- Placentation
- Arrangement of ovules in the ovary.
- Pericarp
- Fruit wall: epicarp, mesocarp, endocarp.
- Pappus
- Ring of hairs on a fruit, aiding wind dispersal.
- Zygomorphic
- Bilaterally symmetrical flower.
- Actinomorphic
- Radially symmetrical flower.
- Sorus
- Cluster of sporangia on a fern leaf.
- Rhizoid
- Hair-like anchoring structure in mosses and fungi.
- Pyrenoid
- Starch-forming body on an algal chloroplast.
- Sporangium
- Structure in which spores are produced.
- Contractile vacuole
- Organelle expelling excess water from a protist.
- Caryopsis
- Dry one-seeded fruit with pericarp fused to the testa (grain).
The Cara's Tips app teaches every topic from the very basics, with quick checks, worked examples and exam practice. It works offline.
Open this lesson in the free appDownload for Android