Botany: Plant Biology and Diversity
What you must understand
Know plant cell features (cellulose wall, chloroplasts, large vacuole) and the organs: root, stem, leaf, flower, fruit, seed. Understand photosynthesis: light-dependent reactions (in thylakoids, produce ATP and NADPH, release O₂ from water) and the Calvin cycle (in stroma, fixes CO₂ into sugars). Know transpiration and transport: xylem carries water and minerals upward, phloem carries sugars. Learn plant groups: algae, mosses (non-vascular, need water for reproduction), ferns (vascular, spores), gymnosperms (naked seeds, cones), angiosperms (flowers, enclosed seeds; monocots vs dicots). Understand flower structure (sepals, petals, stamens, carpels) and pollination/fertilisation. Know plant hormones (auxin, gibberellin) at a basic level and tropisms (phototropism, geotropism).
Traps candidates fall into
- Swapping xylem and phloem - remember xylem = water up; phloem = food/sugar.
- Saying photosynthesis "uses CO₂ and releases O₂" but forgetting the O₂ comes from splitting water, not CO₂.
- Treating mosses as vascular - they are non-vascular and reproduce with water-dependent gametes.
- Confusing gymnosperms (naked seeds, cones) with angiosperms (flowers, fruit).
- Mixing monocots (one cotyledon, parallel veins) and dicots (two cotyledons, net veins).
Worked example / rule of thumb
If a plant is described as having parallel leaf veins and a fibrous root system, it is a monocot. Rule of thumb: moss = no vessels; fern = vessels + spores; gymnosperm = cones + naked seeds; angiosperm = flowers + fruit. For transport, picture the tree: water climbs the xylem, sugars travel in the phloem.