Vocabulary Vocabulary ReviewReview

Ch 29 – Plant Ch 29 – Plant Structure and Structure and

FunctionFunction

In higher plants, the fundamental tissue that is composed of thin-walled living

cells that function in photosynthesis and

storage

Parenchyma

A group of elongated, thick-walled plant cells that support the growth of leaves

and stems

Collenchyma

A type of plant tissue composed of cells that have

thickened secondary cell

walls that function in plant supportSclerenchyma

The outer surface layer of cells of a plant or animal

Epidermis

A waxy or fatty and watertight

layer on the external wall of epidermal cells

Cuticle

A thick-walled, cylindrical cell with tapered ends that is found in xylem and

that provides support and conducts water

and nutrients

Tracheid

In plants, the thin, porous areas of a tracheid cell wall

Pit

In plants, one of the cellular

components of a xylem vessel

Vessel element

In plants, a tube-like structure in the xylem

that is composed of connected cells that conduct water and mineral nutrients

Vessel

One of the component cells of

a sieve tube, which is found

mainly in flowering plants

Sieve tube member

In the phloem of a flowering plant, a

conducting tube that is made up of a series of sieve-tube members stacked end to end

Sieve tube

A region that connects two sieve cells and that has one or more sieve areas, which consist of

clusters of pores through which the cytoplasm of

the cells is connected and through which materials

are transported

Sieve plate

A specialized parenchyma cell that assists in

transport and that gives rise to sieve

tubes in angiosperms

Companion cell

A region of undifferentiated

plant cells that are capable of dividing and developing into

specialized plant tissues

Meristem

The growing region at the tips

of stems and roots in plants

Apical meristem

Dividing tissue that runs parallel to the long axis of a stem or a root

Lateral meristem

In a plant, the lateral meristem

that produces secondary xylem

and phloem

Vascular cambium

A layer of tissue under the cork

layer where cork cells are produced

Cork cambium

In biology, a joint between two adjacent sections in the stem of

a plant where buds form and leaves or branches start to

grow; usually marked by a knot or swelling

Node

The part of a plant stem between two consecutive nodes

Internode

A shoot or flower that has immature

leaves folded in the growing tip

Bud

A modified leaf that forms a protective

covering for a bud until it opens

Bud scale

The tissue that is located in the

center of the stem of most vascular plants and that is used for storage

Pith

Secondary xylem produced in

gymnosperm and dicot stems

Wood

Dark wood in center of tree

Heartwood

Functional, often lighter-colored

wood nearer the outside of the

trunk

Sapwood

The protective outside covering of woody plants,

consisting of cork, cork cambium, and

phloem

Bark

Wood formed during the spring when water is plentiful; vascular

cambium can form new xylem with cells that

are wide and thin walled

Springwood

Wood produced by vascular cambium in summer, when water is limited; smaller cells with

thicker walls

Summerwood

In secondary xylem (wood), the

growth ring formed in one

season

Annual ring

A part of a plant that makes sugars and

other organic compounds and from

which these compounds are

transported to other parts of the plant

Source

Any place where a plant stores or uses organic

nutrients, such as sugar or starches

Sink

The movement of soluble nutrients from one part of a plant to another

Translocation

An explanation for the movement of

carbohydrates in the phloem of plants; holds that carbohydrates are

actively transported into sieve tubes

Pressure-flow hypothesis

The process by which plants release water

vapor into the air through stomata; also the release of water vapor into the air by

other organisms

Transpiration

An explanation for the movement of water up the stem xylem of tall plants; states that water is pulled

up the xylem vessels by the cohesive force between the

water molecules and the adhesion of the water molecules to the rigid

vessel wallsCohesion-tension theory

An organ of climbing plants that grows in

spiral form and wraps around

another body to help support the

plantTendril

The broad, flat portion of a typical

leaf

Blade

The stalk that attaches a leaf to

the stem of a plant

Petiole

A leaf that has an undivided blade

Simple Leaf

A type of leaf in which the blade is

divided into leaflets

Compound leaf

One segment of a compound leaf

Leaflet

In leaves, the tissue between

epidermal layers, where

photosynthesis occurs

Mesophyll

In plants, the layer of vertically elongated cells

that contains chloroplasts, that is located beneath the upper epidermis of

leaves, and that participates in photosynthesis

Palisade mesophyll

Inside a leaf, the tissue that is made up of loosely

arranged parenchyma cells that contain

chloroplasts and are surrounded by air spaces

that promote the diffusion of oxygen,

carbon dioxide, and water throughout the leaf

Spongy mesophyll

In plants, a bundle of vascular tissue that transports

fluids and nutrients

Vein

The arrangement of veins in a leaf

Venation

A parallel arrangement of veins; typical of

the leaves of monocots

Parallel venation

A nonparallel, branching network

of veins that is typical of the

leaves of dicots

Net venation

One of a pair of specialized cells

that border a stoma and

regulate gas exchange

Guard cell