Plant System Wk 1-3 Plant & Cell Struct & Function Part Two

What is the plasma membrane?

Boundary of the living cytoplasm.

What are plant cell walls made of?

Cellulose, hemicellulose, and pectin.

What gives cell walls high tensile strength?

Cellulose microfibrils made of linked glucans.

What replaces pectin in dicot secondary walls?

Lignin.

What are plasmodesmata?

Tubular structures connecting cells for chemical movement.

What is the desmotubule?

ER strand connecting the ER of adjacent cells.

What is included in the endomembrane system?

ER, nuclear envelope, Golgi, vacuole, endosomes, plasma membrane.

What are semiautonomous organelles?

Plastids, mitochondria, chloroplasts.

What shape are parenchyma cells?

Tetrakaidecahedrons (14‑sided).

Are parenchyma cells living or dead?

Living permanent tissues capable of division.

What is totipotent in plants?

A single parenchyma cell can form an entire plant.

Where are parenchyma tissues found?

Pith, cortex, mesophyll, fruit flesh, endosperm.

Functions of parenchyma?

Photosynthesis, storage, secretion, respiration, excretion, transport.

What is chlorenchyma?

Parenchyma with chloroplasts for photosynthesis.

What are transfer cells?

Parenchyma with wall ingrowths for solute transport.

What is vascular parenchyma?

Parenchyma associated with xylem and phloem.

What does xylem parenchyma store?

Starch, fats, tannins, crystals.

What is storage parenchyma?

Stores water, proteins, starch (e.g., potato tubers).

What is aerenchyma?

Parenchyma with air spaces for buoyancy and gas exchange.

What is conjunctive parenchyma?

Root parenchyma forming epiblema

Where is angular collenchyma found?

Primary growth of stems, thickened at cell angles.

What is lacunar collenchyma?

Thickened walls bordering intercellular spaces.

What is lamellar collenchyma?

Thickening on tangential walls, arranged in rows

Main function of collenchyma?

Supports young stems, leaves, and organs.

How does collenchyma enable flexibility?

Provides elasticity and bending tolerance.

What is sclerification?

Wall modification of collenchyma to resist bending.

What are stomata?

Pores with guard cells for gas exchange.

What is phyllotaxis?

Leaf arrangement on a stem.

What is ptyxis?

Relationship of leaf margins to the midrib.

What is circinate vernation?

Fern leaf unrolling from tip downward.

What is a compound leaf?

A leaf with its blade divided into leaflets.

What is a pinnate compound leaf?

Leaflets arranged along both sides of the rachis.

What is a palmate compound leaf?

Leaflets attached at one central point.

What are trichomes?

Epidermal hairs that protect the plant.

What is net venation?

Dicot pattern of interconnected veins.

What is parallel venation?

Monocot pattern of parallel veins.

What are sheathing leaves?

Grass leaves that wrap around the stem.

What are fasciculate leaves?

Conifer leaves grouped in bundles (fascicles).

What are scale leaves?

Reduced protective leaves (Juniper, Asparagus, Cycads).

What are spines?

Modified leaves with vascular bundles.

What are thorns?

Modified stems or branches.

What are prickles?

Epidermal outgrowths without vascular tissue.