Economic Botany: Plant Structure & Growth

Front 1

Tracheids vs vessel elements

Back 1

main difference between tracheids and vessels is that vessels have perforations at the end plates which make them a tube-like, long structure while tracheids do not have end plates.

Front 2

xylem

Back 2

conveys water and dissolved minerals upward from roots into the shoots, on inside of stem, top of leaf
dead at maturity
dead tube cells

Front 3

phloem

Back 3

transports food made in mature leaves to the roots; to nonphotosynthetic parts of the shoot system; and to sites of growth, such as developing leaves and fruits, on outside of stem and bottom of leaf.
dead tube cells & living companion cells

Front 4

adventitious roots

Back 4

roots growing aboveground from stems or from leaves.

Front 5

apical dominance

Back 5

A terminal bud can inhibit the growth of axillary buds.
An evolutionary adaptation that increases the plant’s exposure to light by making it grow taller.
In the absence of a terminal bud, the axillary buds give rise to a vegetative branch complete with its own terminal bud, leaves, and axillary buds.

Front 6

dermal tissue

Back 6

epidermis, periderm (in woody plants)

Front 7

vascular tissue, stele

Back 7

transport of materials between roots and shoots.
Xylem conveys water and dissolved minerals upward from roots into the shoots.
Phloem transports food made in mature leaves to the roots; to nonphotosynthetic parts of the shoot system; and to sites of growth, such as developing leaves and fruits.
The vascular tissue of a root or stem is called the stele.
In angiosperms, the vascular tissue of the root forms a solid central vascular cylinder, while stems and leaves have vascular bundles, strands consisting of xylem and phloem.

Front 8

apical meristem

Back 8

source of all growth
-> protoderm -> dermal tissue, epidermis
->ground meristem -> ground tissues
-> procambium -> vascular tissues

Front 9

root apical meristem

Back 9

growth area for root, covered by root cap

Front 10

parenchyma

Back 10

common type of plant cell, ground tissue
capable of cell division
no plant wall
irregular / globular shape

Front 11

collenchyma

Back 11

support tissue in young stems, ground tissue
regularly shaped, long, narrow, heavier walls
elongates but does not divide typically
secondary wall of varying thickness

Front 12

sclerenchyma

Back 12

support tissue for non-growing stems
usually dead at maturity, no protoplasm
strongly thickened secondary walls - cellulose!

Front 13

fiber

Back 13

long thin type of sclerenchyma near vascular tissues

Front 14

sclereids

Back 14

thickened cells, type of sclerenchyma, resistant cellulose

Front 15

sieve plates

Back 15

control transport between phloem cells

Front 16

procambium

Back 16

becomes vascular tissue

Front 17

protoderm

Back 17

becomes the epidermis, becomes guard cells

Front 18

morphogenesis

Back 18

changes in shape, form - one aspect of plant development

Front 19

differentiation

Back 19

genetically identical cells express different DNA, produce different biomolecules

Front 20

differences between phloem and xylem

Back 20

direction of flow
what is transported
position in stem
control points

Front 21

epidermis

Back 21

guard cells and stomata
trichomes (hairs)
cutical & waxes
periderm - only in plants with cork-meristem

Front 22

periderm

Back 22

outer protective tissue that replaces epidermis when secondary growth occurs. Includes cork, cork-cambium, phelloderm (?)

Front 23

phenotype plasticity

Back 23

same genes, different environment, different plant shape

Front 24

reaction norms

Back 24

range of phenotypical response

Front 25

indeterminate

Back 25

plant body plans are flexible, not predicted

Front 26

allocation of resources

Back 26

growth, defense, reproduction

Front 27

primary growth

Back 27

from meristems

Front 28

secondary growth

Back 28

from vascular cambium or cork cambium
periderm = cork cambium + cork

Front 29

monocot

Back 29

vascular bundles scattered throughout
leaf veins run parallel

Front 30

dicot

Back 30

vascular bundles are arranged in a circle
leaf veins in network

Front 31

palisade mesophyll

Back 31

elongated cells containing chloroplasts

Front 32

bryophytes

Back 32

plants that lack vascular tissue
materials diffuse between cells

Front 33

homeobox genes

Back 33

overlapping sets of genes are expressed to control the expression of floral parts

Front 34

endodermis

Back 34

separates pith from vascular tissues

Front 35

transverse rays

Back 35

phloem that extends towards inside of trunk

Front 36

ray initials

Back 36

cells that create transverse rays of phloem

Front 37

fusiform initials

Back 37

creates new layers of xylem and phloem

Front 38

wood

Back 38

secondary xylem

Front 39

sapwood

Back 39

secondary xylem that still transports water

Front 40

heartwood

Back 40

no active transport, storage of secondary compounds, structural support

Front 41

lenticels

Back 41

since periderm tissues (=cork cambium + cork) are air and water tight, needed for gas exchange

Front 42

functions of roots

Back 42

anchorage / support
absortpion (water & nutrients)
storage (nutrients, photosynthate)
transport, microrhysal fungal sharing
clonal regeneration
(sometimes) protection - spines

Front 43

zone of elongation

Back 43

root growth area where differentiation begins

Front 44

zone of differentiation

Back 44

root growth area where root hairs are developed

Front 45

apoplast

Back 45

transport pathway outside cells & in cell walls

Front 46

symplast

Back 46

transport pathway inside cells through shared cytoplasm, cells joined by plasmodesmata

Front 47

Casparian strips

Back 47

waterproof strips in all plants with vascular bundles
control systems that separate the vascular stele from the cortex
ensure transport is through symplast

Front 48

pericycle

Back 48

meristematic tissue that makes lateral roots
analogous to stem cork cambium

Front 49

monocot root

Back 49

fibrous root system, network of veins

Front 50

dicot root

Back 50

taproot, with lateral branch roots

Front 51

mycorrhizae

Back 51

symbiosis of plant roots & soil fungi