Plant Science and Plant Propagation
Core concepts
You must understand plant structure and function: roots absorb water and minerals and anchor the plant; stems transport and support; leaves are the main site of photosynthesis; flowers are reproductive organs. Know the difference between monocotyledons (one seed leaf, parallel veins, fibrous roots) and dicotyledons (two seed leaves, net veins, taproot). Understand transpiration, respiration and photosynthesis, and how light, water, temperature and carbon dioxide limit growth. Learn the parts of a flower and the difference between pollination and fertilisation.
Propagation
Separate sexual propagation (seed, involving meiosis and genetic variation) from asexual or vegetative propagation (cuttings, division, layering, grafting, budding, tubers, bulbs, runners). Asexual propagation produces clones, so it preserves cultivar characteristics but gives no genetic variation. Know when each is used: seed for annuals and rootstocks, cuttings for named cultivars, grafting to combine a scion with a resistant or vigorous rootstock.
Traps in questions
Questions often confuse pollination (transfer of pollen) with fertilisation (fusion of gametes). Another trap is claiming all cuttings need the same conditions; softwood, semi-ripe and hardwood cuttings differ in timing and treatment. Candidates also muddle the roles of nodes and internodes: roots and shoots arise at nodes, never at internodes.
Worked example
A candidate is asked the quickest reliable way to reproduce a named rose cultivar true to type. Seed gives variation, so the answer is vegetative: semi-ripe cuttings or budding onto a rootstock. Rule of thumb: if the plant has a cultivar name in single quotes, propagate it vegetatively.