04 Plant Anatomy Structure

What are the three main vegetative organs of a plant?

Roots, stems, and leaves.

What does the root cap do?

Protects the growing root tip.

What do root hairs do?

Increase root surface area for water and mineral uptake.

What is a node on a stem?

A point where a leaf or bud attaches.

What is an internode?

A segment of stem between two nodes.

What is an axillary bud?

A bud located where a leaf joins a stem; it can grow into a branch or flower.

What is an apical bud?

A bud at the tip of a shoot that contributes to lengthwise growth.

What is the blade of a leaf?

The broad, flattened portion of a leaf.

What is a petiole?

A stalk that attaches a leaf blade to the stem.

What is a simple leaf?

A leaf with a single blade, which may be lobed.

What is a compound leaf?

A leaf whose blade is divided into leaflets.

What is parenchyma?

Living plant tissue often involved in photosynthesis, storage, and repair.

What is collenchyma?

Living support tissue with unevenly thickened primary cell walls.

What is sclerenchyma?

Support tissue with thick, often lignified secondary cell walls; many cells are dead at maturity.

What are sclereids?

Short, variably shaped sclerenchyma cells providing hardness or support.

What are fibers in plant tissue?

Elongated sclerenchyma cells that provide tensile strength.

What does xylem transport?

Water and dissolved minerals, predominantly from roots upward.

What does phloem transport?

Sugars and other organic compounds from sources to sinks.

What are tracheids?

Water-conducting xylem cells that are dead at maturity and have pits.

What are vessel elements?

Xylem cells that join end to end to form water-conducting vessels; dead at maturity.

What are sieve-tube elements?

Living phloem conducting cells that lose much of their internal machinery at maturity.

What do companion cells do?

Support and maintain sieve-tube elements and help load or unload sugars.

What is a sieve plate?

A perforated end wall between adjacent sieve-tube elements.

What is an apical meristem?

A region of actively dividing cells responsible for primary (length) growth.

What is a lateral meristem?

A meristem responsible for secondary (girth) growth.

What does vascular cambium produce?

Secondary xylem toward the inside and secondary phloem toward the outside.

What does cork cambium produce?

Protective periderm tissue, including cork cells.

What is the epidermis?

The outer protective cell layer of young plant organs.

What is the cuticle?

A waxy covering that reduces water loss from aerial plant surfaces.

What is the cortex?

Ground tissue between the epidermis and central vascular tissue in roots and stems.

What is the pith?

Central ground tissue, commonly present in stems.

What is the endodermis?

The innermost cortex layer of a root that regulates entry into the vascular cylinder.

What is the pericycle?

A root layer just inside the endodermis from which lateral roots typically arise.

What is a vascular bundle?

A strand containing xylem and phloem.

How do vascular bundles typically differ in monocot and eudicot stems?

Monocot stem bundles are scattered; eudicot stem bundles commonly form a ring.

What is an atactostele?

A stem arrangement with scattered vascular bundles, typical of monocots.

What is an eustele?

A stem arrangement with vascular bundles in a ring, typical of many eudicots.

What is mesophyll?

Photosynthetic ground tissue inside a leaf.

What is palisade mesophyll?

Tightly packed, elongated photosynthetic cells often near the upper leaf surface.

What is spongy mesophyll?

Loosely arranged photosynthetic tissue with air spaces.

What are stomata?

Pores in the epidermis that allow gas exchange and water-vapor loss.

What are guard cells?

Paired cells that control stomatal opening and closure.

What is a leaf vein?

A vascular bundle supplying water and exporting photosynthetic products.

What is bark?

Tissues outside the vascular cambium in a woody stem or root.

What does the periderm replace in woody stems?

The epidermis as secondary growth expands stem circumference.

What are sepals?

Flower parts that generally protect the developing flower bud.

What are petals?

Flower parts often involved in attracting pollinators.

What are stamens?

Male flower structures composed of filament and anther.

What are carpels?

Female flower structures including stigma, style, and ovary.

What is the difference between a longitudinal and a transverse section?

Longitudinal runs along the length; transverse (cross) section cuts across it.