Plant Structure and Function Overview

Plant Structure and Function

• Plants are eukaryotes, multicellular organisms containing chlorophyll.
• Plants can be categorized as non-vascular or vascular.
• Non-vascular plants lack internal water transport systems, typically found in moist habitats (e.g., mosses).
• Vascular plants have internal vessels for water and nutrient transport. These include roots, stems, leaves & flowers (e.g., trees, bushes).
• Vascular plants are categorized as gymnosperms or angiosperms.
• Gymnosperms are "naked seed" plants with seeds not enclosed in fruit (e.g., pine trees).
• Angiosperms are "container seed" plants with seeds enclosed in fruit (e.g., flowering plants)

Plant Reproduction

• Reproduction is crucial for species survival.
• Plants reproduce both sexually and asexually.
• Asexual reproduction involves creating offspring without combining genetic material from two parents.
• Sexual reproduction in plants involves the fusion of gametes (sperm and egg), differing from animal reproduction with a unique process called double fertilization which involves different fertilization events.

Modified Stems

• Modified stems exhibit diverse forms and functions.
• Stolons/runners spread by producing new plants from nodes.
• Rhizomes are horizontal, underground stems.
• Tubers are enlarged underground stems for food storage.
• Bulbs are thickened, underground bases of leaves.
• Corms are vertical, short, and thick underground stems.
• Succulents are fleshy stems for water storage.

Flower Parts

• Flowers are reproductive organs with male (stamen) and female (pistil) parts.
• Stamens produce pollen (male gamete).
• Pistils produce ovules (female gamete).
• Sepals protect the flower bud, often green.
• Petals attract pollinators.
• Corolla is a collective term for the petals.
• Calyx is a collective term for the sepals.

Pollination

• Pollination is the transfer of pollen from stamen to pistil.
• Self-pollination involves pollen from the same plant.
• Cross-pollination involves pollen transfer from one plant to another.
• Pollination is aided by agents like wind, water, and animals.

Gymnosperms vs. Angiosperms Comparison (Basic)

• Seed: Gymnosperms have naked seeds, angiosperms have seeds in fruit.
• Stem: Gymnosperms may have no rings of vascular bundles, angiosperms may have rings of vascular bundles
• Leaves: Gymnosperms often have needle- or scale-like leaves, angiosperms have various leaf shapes.