Plant Organ Systems Overview

Form Follows Function

Organs and organ systems adapt shape to suit their purpose

Root Hairs

Extensions on roots for water absorption

Three Organ Types

Roots (anchoring, absorption), shoots (growth), leaves (photosynthesis)

Three Tissue Types

Dermal (protection), vascular (transport), ground (photosynthesis)

Primary Growth

Vertical growth in plants

Secondary Growth

Lateral growth, thickening in plants

Meristems

Sites of plant cell growth; apical for primary, lateral for secondary growth

Development

Includes growth, morphogenesis, and cell differentiation

Developmental Plasticity

Organisms' ability to adapt development to environmental conditions

Model Organism

Arabidopsis; useful for plant biology studies due to small size and genome

Taproot

Main root anchoring plant into soil

Root Hairs

Increase absorptive surface area of roots

Apical Bud

Growing shoot tip stimulating shoot elongation

Axillary Bud

Lateral branch on plant stem

Periderm

Replaces older epidermis in woody plants

Cuticle

Waxy layer covering plant epidermis to prevent water loss

Stomata

Pores in leaves for gas exchange

Xylem

Conducts water and nutrients upward in plants

Phloem

Transports sugars in plants

Pith

Central tissue in plant stems

Cortex

Outer tissue layer around vascular tissue in plants