Lesson 2: Plant Anatomy

Cells

Basic building blocks of plants, distinguished by characteristics such as vacuoles and cell wall thickness.

Tissues

Groups of organized cells that perform a shared function.

Organs

Structures made of multiple tissues, such as leaves, roots, and stems.

Root System

The part of the plant generally below ground, responsible for anchoring the plant and absorbing water and minerals.

Shoot System

Comprises stems, leaves, and flowers of the plant.

Monocots

Angiosperms with scattered vascular bundles in stems and ringed vascular bundles in roots.

Eudicots

Angiosperms with vascular bundles arranged in rings in stems and a star-shaped xylem core in roots.

Meristems

Localized regions in plants that contain undifferentiated cells capable of division and growth.

Apical Meristems

Located at the tips of roots and shoots, responsible for primary growth.

Protoderm

A primary meristem that forms dermal tissue.

Procambium

A primary meristem that forms primary vascular tissue.

Ground Meristem

A primary meristem that forms ground tissue.

Lateral Meristems

Meristems responsible for secondary growth, increasing the diameter of stems and roots.

Vascular Cambium

A lateral meristem that produces secondary xylem (wood) and secondary phloem.

Cork Cambium

A lateral meristem that produces cork cells, contributing to the outer bark.

Intercalary Meristems

Located in plants like corn, allowing lengthening of the internode.

Primary Cell Wall

The outermost layer of a plant cell made of cellulose.

Secondary Cell Wall

Wall containing lignin that provides strength.

Epidermis

The outer layer of plant cells, usually one cell thick, protected by a waxy cuticle.

Guard Cells

Cells that flank the stomata, regulating gas exchange and water loss.

Trichomes

Hair-like outgrowths on plants that offer protection.

Root Hairs

Extensions of root cells that increase surface area for water absorption.

Parenchyma

The most common type of ground tissue, thin-walled and involved in photosynthesis and storage.

Collenchyma

Living cells at maturity, providing flexible support with irregularly thickened walls.

Sclerenchyma

Dead cells at maturity with thick walls, providing structural support.

Xylem

Vascular tissue that conducts water and minerals.

Phloem

Vascular tissue that conducts food (sucrose) throughout the plant.

Leaves

Vegetative organs composed of a blade and a petiole, involved in photosynthesis.

Mesophyll

Ground tissue in leaves dedicated to photosynthesis.

Zone of Cell Division

Location of the apical meristem in roots where cell division occurs.

Endodermis

The innermost layer of the root cortex containing the Casparian strip.

Annual Rings

Concentric layers formed by seasonal variations in secondary xylem.

Periderm

A protective tissue that replaces the epidermis in woody stems.

Lenticels

Unsuberized patches in bark allowing for gas exchange.

Annuals

Plants that live, reproduce, and die within a single year.

Biennials

Plants with a two-year cycle, vegetative growth in the first year and reproduction in the second.

Perennials

Plants that live and grow year after year, which can be either herbaceous or woody.