Plant Science
Plant Science
Plant Science tests classification, morphology, anatomy, reproduction and the identification of important crop families. You should be able to use structural clues rather than memorised names alone.
Core rules
- Binomial nomenclature gives a genus and species name; the genus is capitalised and the species is lower case.
- Monocots usually have fibrous roots, parallel venation, trimerous flowers and scattered vascular bundles. Dicots usually have tap roots, reticulate venation, tetramerous or pentamerous flowers and vascular bundles in a ring.
- Poaceae includes wheat, rice, maize and sugarcane; Fabaceae includes gram, pea, lentil and groundnut; Solanaceae includes tomato, potato, brinjal and chilli; Malvaceae includes cotton.
- Grasses bear spikelets with glumes, lemma and palea rather than ordinary open flowers.
- Hypogeal germination keeps cotyledons below ground, as in pea and gram; epigeal germination lifts cotyledons above ground, as in castor.
Worked example
A plant has a hollow jointed culm, a ligule at the leaf base, parallel venation and spikelets. The scattered vascular bundles confirm a monocot, and the spikelet and ligule point to Poaceae. The reasoning is to combine vegetative anatomy with floral structures, not to rely on leaf shape alone.
Mark-losing traps
- Reversing hypogeal and epigeal germination.
- Forgetting that groundnut is a legume despite its underground pods.
- Describing a grass flower as a simple complete flower instead of a spikelet.
- Confusing axile placentation in Solanaceae with parietal placentation in many Brassicaceae.