Plant Cells, Tissues, and Organ Systems

Vocabulary flashcards covering plant cell types, tissues, and organ systems as described in the video notes.

Shoot system

The aboveground plant organ system that includes leaves and stems (vegetative organs) and reproductive organs (flowers and fruits).

Root system

The underground plant organ system consisting of roots; only one organ: roots.

Ground tissue system

Main tissue system for storage, photosynthesis, and support; includes mesophyll and pith.

Vascular tissue system

Tissue system for transport; composed of xylem and phloem.

Dermal tissue system

Protective outer covering; includes epidermis and periderm.

Simple tissue

Tissue composed of a single cell type.

Complex tissue

Tissue composed of multiple cell types.

Parenchyma

Living, versatile simple tissue; functions in photosynthesis, respiration, storage; can differentiate into other cell types; forms cortex, pith, and mesophyll.

Collenchyma

Simple, elongated tissue; alive at maturity; thickened corners; provides flexible support for growing parts.

Sclerenchyma

Simple tissue with thick lignified secondary walls; usually dead at maturity; provides rigid support.

Fibers

Long, narrow sclerenchyma cells that form continuous cylinders or strands for support.

Sclerids

Sclerenchyma cells with varied shapes; contribute to hard tissues like seed coats.

Vessel elements

Water-conducting xylem cells that align end-to-end to form vessels.

Tracheids

Elongated water-conducting xylem cells with tapered ends.

Sieve-tube members

Food-conducting phloem cells that are living but lack nucleus in mature form.

Companion cells

Specialized parenchyma cells that assist sieve-tube members in loading and unloading sugars.

Xylem

Vascular tissue that transports water and minerals; includes vessel elements, tracheids, and supportive fibers.

Phloem

Vascular tissue that transports sugars and other metabolites; includes sieve-tube elements and companion cells.

Epidermis

Outer single layer of cells covering the plant; often coated with cutin.

Guard cells

Specialized epidermal cells that regulate stomatal opening for gas exchange.

Subsidiary cells

Cells associated with guard cells aiding stomatal function in some species.

Trichomes

Outgrowths of epidermal cells; roots form root hairs; leaves/stems may have protective structures.

Root hairs

Epidermal extensions increasing surface area for water and nutrient absorption.

Periderm

Protective tissue replacing epidermis in older stems/roots; consists of phellem, phellogen, and phelloderm.

Phellem

Outside cork cells; dead at maturity; waxy suberin in walls.

Phellogen

Cork cambium; lateral meristem that produces phellem and phelloderm.

Phelloderm

Parenchyma-like cells between cork cambium and cortex.

Meristem

Group of undifferentiated cells that gives rise to tissues and organs.

Turgor pressure

Internal water pressure in cells that pushes against the cell wall, making cells rigid.

Cortex

Outer region of stems and roots between epidermis and vascular tissue; storage and support.

Pith

Central storage tissue in stems.

Mesophyll

Leaf tissue specialized for photosynthesis; includes palisade and spongy layers.

Palisade mesophyll

Tall, closely packed cells near the upper leaf surface; main site of photosynthesis.

Spongy mesophyll

Loosely arranged leaf cells with air spaces aiding gas exchange.

Pectin

Polysaccharide in plant cell walls that glues cells together.