Plant Structure, Development, and Anatomy

Comprehensive vocabulary flashcards covering plant cell structures, primary tissue systems, seed development, root anatomy, and modified shoots based on the lecture transcript.

Cellulose

A plant cell wall component that provides turgor pressure and rigidity.

Hemicellulose

A plant cell wall component that provides flexible strength.

Pectin

A cell wall component that cements cells together and serves as the main component of the middle lamella.

Lignin

A cell wall component providing strength that is deposited on the inner side of the primary cell wall to form the secondary cell wall.

Apoplastic transport

A "dead system" of transport that moves substances through plant cell walls.

Symplastic transport

Cell-to-cell transport that moves substances through plasmodesmata and cytoplasm.

Plasmodesmata

Channels in the cell wall between plant cells involved in symplastic transport.

Middle lamella

The intercellular layer cementing adjacent plant cells together, composed mainly of pectin.

Chloroplasts

Plastids responsible for conducting photosynthesis.

Chromoplasts

Plastids that synthesize and store accessory pigments.

Leucoplasts

Non-pigmented plastids that function in the storage of carbs.

Vacuole

A plant organelle that maintains turgor pressure, provides water storage, and stores water-soluble pigments.

Dermal tissue system

Tissue system derived from the protoderm, consisting of the epiderm in non-woody plants and periderm in woody plants.

Ground tissue system

Tissue system derived from the ground meristem, composed of parenchyma, sclerenchyma, and collenchyma tissues.

Vascular tissue system

Tissue system derived from vascular cambium, consisting of complex xylem and phloem tissues.

Parenchyma

The most abundant ground tissue cell type in plants; totipotent cells that make up most of the cortex and pith.

Collenchyma

Living support cells located beneath the epidermis in stems and petioles with unevenly thickened cell walls lacking lignin.

Sclerenchyma

Lignified support cells that can be living or dead, categorized as sclereids or fibers.

Tracheids

Elongated, tapering, lignified dead xylem cells that provide support and water transport; dominant in gymnosperms.

Vessel elements

Dead, lignified water-conducting xylem cells that are shorter than tracheids; dominant in angiosperms.

Sieve tube

Living phloem cells lacking a nucleus that transport sugar through sieve plate perforations.

Companion cells

Phloem cells attached to sieve tube elements that function to load and unload the sieve plate.

Trichomes

Epidermal outgrowths that function to capture prey, disperse heat, prevent water loss, absorb water, or secrete toxins.

Xylem

A complex vascular tissue that transfers water and ions.

Phloem

A complex vascular tissue that transfers sugar.

Seed bank

A collection of seeds maintained primarily for research purposes.

Seed vault

A secure facility used for the long-term conservation of seeds.

Endosperm

The nutritive tissue in a seed that feeds the developing embryo.

Funiculus

The stalk that attaches an ovule to the ovary, serving to anchor it and transport nutrients.

Micropyle

A small opening in a seed that allows water and air transport and serves as an exit hole for the radicle.

Radicle

The embryonic root of a plant.

Plumule

The embryonic shoot of a plant.

Coleoptile

A protective sheath that covers the plumule as it pushes through the soil.

Coleorhizae

A protective sheath that shields the radicle during early growth.

Cotyledon

An embryonic leaf of a seed plant.

Epicotyl

The embryonic stem region located above the cotyledons and below the plumule.

Hypocotyl

The embryonic stem region located below the cotyledons and above the radicle.

Hypogeal plants

Plants in which the epicotyl develops into the shoot while the cotyledons remain underground.

Epigeal plants

Plants in which the hypocotyl develops into the shoot and lifts the cotyledons above ground.

Dormant seed

A seed that requires a specific environmental trigger to break resting state and initiate growth.

Quiescent seed

A seed that only requires $H_2O$, favorable temperature, or $O_2$ to initiate growth.

Recalcitrant seed

A seed that cannot tolerate desiccation or freezing because it lacks maturation drying.

Viviparous seed

A seed that germinates while still attached to the parent plant.

Region of cell division

Root apical zone containing the primary meristems: protoderm, procambium, and ground meristem.

Region of cell elongation

Root zone where newly formed cells elongate and push the root tip forward through the soil.

Region of cell maturation

Root zone containing differentiated true tissues and where root hairs are exclusively found.

Casparian strip

A hydrophobic barrier in root endodermis that blocks apoplastic transport.

Pericycle

A layer of parenchyma cells in the root from which branch (lateral) roots originate.

Arenchyma

A spongy plant tissue adapted for aquatic plants.

Pneumatophores

Specialized breathing roots that grow upward against gravity.

Root nodules

Root swellings hosting nitrogen fixation that appear red or pink inside due to leghemoglobin.

Rhizome

A horizontal, underground modified stem.

Stolon

A horizontal, aboveground modified stem.

Tuber

A modified underground stem specialized for storage, such as a potato.

Corm

A leafless, swollen underground stem base functioning as a storage organ.

Bulb

An underground storage organ primarily composed of modified fleshy leaves.