Plant biology for the Biology Olympiad

Explore plant classification from non-vascular to vascular plants, distinguishing seedless and seed plants, and tracing gymnosperms and angiosperms, including monocots and dicots.

Trace the evolution of land plants from aquatic green algae. The lecture highlights features like multicellular embryos, alternation of generations, sporangia with spores and pollen, a cuticle, and mycorrhizal relationships.

Explore nonvascular plants, including mosses, liverworts, and hornworts, which have a dominant gametophyte and form a thallus without vascular tissue, with fertilization requiring water to reach archegonia.

Explore seedless vascular plants—club mosses, ferns, horsetails, and whisk ferns—focusing on xylem and phloem transport, spores, and alternation of generations.

explore vascular seed plants, comparing gymnosperms and angiosperms, and explain pollen grains, pollen tubes, megaspores, embryo sacs, double fertilization, seeds, endosperm, and seed dispersal.

Learn about gymnosperms, including conifers, Ginkgo, and other groups, focusing on their dominant sporophyte lifecycle, naked seeds, pollen tubes, fertilization, and seed development on cones.

Explore angiosperms, flowering plants with flowers and fruits, featuring double fertilization where one sperm forms the embryo and another forms nourishing endosperm, via pollen grains and animal and wind pollination.

Explore angiosperm reproduction by detailing embryo sac formation, double fertilization, and endosperm development, and examine pollination by wind, water, and animals.

Compare monocots and dicots by seed structure and leaf venation. Note one versus two cotyledons, and the differences in root systems and vascular arrangement.

Explore plant tissues and organs, including dermal, ground, and vascular tissues; learn epidermis and cuticle, parenchyma, collenchyma, and sclerenchyma functions, and xylem and phloem transport.

Explore how roots anchor plants, absorb water and minerals, and increase surface area; distinguish taproot and fibrous systems, adventitious roots, tubers, and gravity sensing in the root cap.

Support leaves and flowers, transport water and nutrients, store resources, and enable photosynthesis when green. Identify nodes, internodes, petioles, apex, and tubers, bulbs, stolons, tendrils.

Analyze leaf structure, venation, and the arrangement of leaves, from blade and petiole to parallel or net-like veins, and explore modifications for photosynthesis, climbing, defense, water storage, and carnivorous plants.

Discover primary growth lengthening plant parts via apical and intercalary meristems. Learn how secondary growth thickens stems with the vascular and cork cambiums, producing xylem, phloem, bark, and annual rings.

Explore monocot plant families, including lily, orchid, grass, palm, and bromeliad groups, with notes on flower structure, umbrella inflorescences, and key genera like vanilla and Ananas.

Survey major dicot families, including Magnoliaceae, Ranunculaceae, Asteraceae, Rosaceae, Fabaceae, Malvaceae, Euphorbiaceae, Moraceae, Cactaceae, Brassicaceae, Myrtaceae, Lamiaceae, Solanaceae, Rubiaceae, and others, with highlights on distinctive flowers and fruits.

Explain the flower's female parts: pistil with stigma, style, ovary, and receptacle, and the male part, stamen, while noting embryo sac formation and double fertilization basics.

explore flower anatomy from the calyx and petals to the receptacle, and learn about complete and incomplete flowers, perfect and imperfect flowers, and variations in symmetry, insertion, and placenta types.

Explain how the abc model uses class a, b, and c genes to pattern the four whorls into sepals, petals, stamens, and carpels, including A and C antagonism.

Explore floral formulas and diagrams that encode flower structure using symbols for symmetry, the calyx (K), the cola with petals, statements (A), and couples (G), enabling analysis of flower architecture.

Explore the basic anatomy and classification of fruits, including dry and fleshy types, simple, aggregate, and multiple fruits, with examples and Exo Cup, Meadow Cup, and Endo Cup roles.

Explore cross sections across stele types from protostele to monocot arrangements, detailing xylem, phloem, pith, endodermis and Casparian strip, suberin, plus three routes: symplastic, apoplastic, transmembrane, no secondary growth.

Explore apoplastic and symplastic pathways of water and solutes across the epidermis and cortex into the vascular cylinder, and distinguish monocot and dicot root cross sections.

Explore cross sections of stems in monocots and dicots, distinguishing open versus closed vascular bundles, and how vascular cambium enables secondary growth and thickening.

Explore how woody stems grow via vascular cambium, forming secondary xylem and phloem, cork and bark, and how early and late wood create annual rings revealing age and climate.

Analyze cross sections of gymnosperms, noting cortex, cork formation, stele with xylem and tracheids, and absence of vessel elements and companion cells; examine pine needle cuticle and sunken stomata.

Analyze cross sections of dicot and monocot leaves, highlighting differences in venation (net-like vs parallel), mesophyll organization (palisade and spongy), epidermis and cuticle, and vascular bundle arrangement.

Explore leaf cross sections to compare C3, C4, and CAM photosynthesis, from bundle sheath and mesophyll organization to pep carboxylase activity, and discuss aquatic and desert plant adaptations.

Explore how desert plants like cacti and succulents survive extreme heat and drought through water storage, thick cuticles, sunken stomata, reduced surface area, and the CAM pathway.

Explore how plant hormones, especially auxins, regulate growth, phototropism, apical dominance, and fruit development including parthenocarpy, and how ethylene and abscisic acid govern leaf abscission.

Gibberellins stimulate seed germination and shoot elongation; cytokinins promote cell division and delay leaf senescence, while high gibberellin levels may cause abnormal growth or foolish seedling disease.

Explore how ethylene and abscisic acid regulate plant growth, senescence, and stress responses, including growth inhibition, fruit ripening, leaf and fruit abscission, stomatal closure, and seed dormancy.

Classify plant movements into spontaneous and induced, detailing growth movements such as phototropism and geotropism, and non directional gnostic movements like nyctinasty, with examples like mimosa and venus flytrap.

Examine how photoperiod governs flowering via the Pr and Pfr forms. Learn how day and night length, plus brief light cues, determine short-day and long-day plant responses.