Bio104 Chapter 25 Key Terms

Front 1

root system

Back 1

Includes the main root and any and all of its lateral (side) branches.

Front 2

shoot system

Back 2

Aboveground portion of a plant consisting of the stem, leaves, and flowers.

Front 3

organ

Back 3

Combination of two or more different tissues performing a common function.

Front 4

perennial

Back 4

Flowering plant that lives more than one growing season because the underground parts regrow each season.

Front 5

stem

Back 5

Usually the upright, vertical portion of a plant that transports substances to and from the leaves.

Front 6

node

Back 6

In plants, the place where one or more leaves attach to a stem.

Front 7

internode

Back 7

In vascular plants, the region of a stem between two successive nodes.

Front 8

leaf

Back 8

Lateral appendage of a stem, highly variable in structure, often contain cells that carry out photosynthesis.

Front 9

deciduous

Back 9

Plant which sheds its leaves annually.

Front 10

blade

Back 10

Broad, expanded portion of a plant leaf that may be single or compound leaflets.

Front 11

petiole

Back 11

The part of a plant leaf that connects the blade to the stem.

Front 12

axillary bud

Back 12

Bud located in the axil of a leaf.

Front 13

cotyledon

Back 13

Seed leaf for embryo of a flowering plant; provides nutrient molecules for the developing plant before photosynthesis begins.

Front 14

monocots

Back 14

Abbreviation of monocotyledon. Flowering plant group; members have one embryonic leaf (cotyledon) parallel-veined leaves, scattered vascular bundles, flower parts in threes or multiples of three, and other characteristics.

Front 15

eudicots

Back 15

Abbreviation of eudicotyledon. Flowering plant group; members have two embryonic leaves (cotyledons), net-veined leaves, vascular bundles in a ring, flower parts in fours or fives and their multiples, and other characteristics.

Front 16

meristem

Back 16

Undifferentiated embryonic tissue in the active growth regions of plants.

Front 17

epidermal tissue

Back 17

Exterior tissue, usually one cell thick, of leaves, young stems, roots, and other parts of plants.

Front 18

ground tissue

Back 18

Tissue that constitutes most of the body of a plant; consists of parenchyma, collenchyma, and sclerenchyma cells that function in storage, basic metabolism, and support.

Front 19

vascular tissue

Back 19

Transport tissue in plants, consisting of xylem and phloem.

Front 20

epidermis

Back 20

In mammals, the outer, protective layer of the skin; in plants, tissue that covers roots, leaves, and stems of nonwoody organisms.

Front 21

cuticle

Back 21

Waxy layer covering the epidermis of plants that protects the plant against water loss and disease-causing organisms.

Front 22

root hair

Back 22

Extension of a root epidermal cell that collectively increases the surface area for the absorption of water and minerals.

Front 23

trichomes

Back 23

In plants, specialized outgrowth of the epidermis (e.g, root hairs)

Front 24

stomata

Back 24

Small opening between two guard cells on the underside of leaf epidermis through which gases pass.

Front 25

periderm

Back 25

Protective tissue that replaces epidermis; includes cork, cork cambium.

Front 26

cork

Back 26

Outer covering of the bark of trees; made of dead cells that may be sloughed off.

Front 27

lenticel

Back 27

Frond of usually numerous, lightly rasied, somewhat spongy, groups of cells in the bark of woody plants. Permits gas exchange between the interior of a plant and the external atmosphere.

Front 28

parenchyma

Back 28

Plant tissue composed of the least-specialized of all plant cells; found in all organs of a plant.

Front 29

collenchyma

Back 29

Plant tissue composed of cells with unevenly thickened walls; supports growth of stems and petioles.

Front 30

sclerenchyma

Back 30

Plant tissue composed of cells with heavily lignified cell walls; functions in support.

Front 31

lignin

Back 31

Chemical that hardens the cell walls of plants.

Front 32

xylem

Back 32

Vascular tissue that transports water and mineral solutes upward through the plant body; it contains vessel elements and tracheids.

Front 33

phloem

Back 33

Vascular tissue that conducts organic solutes in plants; contains sieve-tube members and companion.

Front 34

vessel element

Back 34

Cell that joins with others to form a major conducting tube found in xylem.

Front 35

tracheid

Back 35

In vascular plants, type of cell in xylem that has tapered ends and pits through which water and minerals flow.

Front 36

pit

Back 36

Any depression or opening; usually in reference to the small openings cell walls of xylem cells that function in providing a continium between adjacent xylem cells.

Front 37

sieve-tube member

Back 37

Member that joins with others in the phloem tissue of plants as a means of transport for nutrient sap.

Front 38

apical meristem

Back 38

In vascular plants, masses of cells in the root and shoot that reproduce and elongate as primary growth occurs.

Front 39

root cap

Back 39

Protective cover of the root tip, whose cells are constantly replaced as they are ground off when the root pushes through rough soil particles.

Front 40

cortex

Back 40

In plants, ground tissue bounded by the epidermis and vascular tissue in stems and roots.

Front 41

Casparian strip

Back 41

Layer of impermeable lignin and suberin bordering four sides of root endodermal cells; prevents water and solute transport between adjacent cells.

Front 42

pith

Back 42

Parenchyma tissue in the center of some stems and roots.

Front 43

primary root

Back 43

Original root that grows straight down and remains the dominant root of the plant; contrasts with fibrous root system.

Front 44

taproot

Back 44

Main axis of a root that penetrates deeply and is used by certain plants (such as carrots) for food storage.

Front 45

fibrous root system

Back 45

In most monocots, a mass of similarly sized roots that cling to the soil.

Front 46

adventitious roots

Back 46

Fibrous roots that develop from stems or leaves, such as the prop roots of corn or the holdfast roots of ivy.

Front 47

root nodule

Back 47

Structure on plant root that contains nitrogen-fixing bacteria.

Front 48

terminal bud

Back 48

Bud that develops at the apex of a shoot.

Front 49

herbaceous stem

Back 49

Nonwoody stem.

Front 50

bark

Back 50

External part of a tree, containing cork, cork cambium, and phloem.

Front 51

vascular cambium

Back 51

In plants, lateral meristem that produces secondary phloem and secondary xylem.

Front 52

wood

Back 52

Secondary xylem that builds up year after year in woody plants and becomes the annual rings.

Front 53

stolon

Back 53

Stem that grows horizontally along the ground and may give rise to new plants where it contacts the soil-e.g., the runners of a strawberry plant.

Front 54

rhizome

Back 54

Rootlike underground stem.

Front 55

mesophyll

Back 55

Inner, thickest layer of a leaf consisting of palisade and spongy mesophyll; the site of most of photosynthesis.

Front 56

palisade mesophyll

Back 56

Layer of tissue in a plant leaf containing elongated cells with many chloroplasts.

Front 57

spongy mesophylll

Back 57

Layer of tissue in a plant leaf containing loosely packed cells, increasing the amount of surface area for gas exchange.