Vuw Biol113 Test 1 2014

Front 1

Organismal Theory

Back 1

"The plan forms the cells not the cells the plant" looks at the organism as a whole and considers it to be of prime importance

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Shoot

Back 2

repeating modules, node-internode-axillary bud-shoot

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Node

Back 3

swelling on stem where one or more leaves is attached

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Internode

Back 4

space between nodes

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Auxillary Bud

Back 5

bud that will form a side shoot, in the joint between stem and leaf

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Leaf

Back 6

appendage adapted for photosyntheis

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Tendril

Back 7

can be a modified stem or root, is a thin cylindrical structure that coils around other objects

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Stolon

Back 8

slender horizontal stem on or beneath the soil surface, for example strawberry runners, not usually the main stem

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Tuber

Back 9

fleshy swollen tip of an underground stem, for example jerusalem artichoke

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Rhizome

Back 10

swollen underground, horizonatal stem for example, ginger

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Corm

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short, vertical fleshy underground stem for example gladiolus

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Bulb

Back 12

short undergrown stem surrounded by leaves, for example tulip

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Cladode

Back 13

flattened shoot which photosynthesises for example, cactus

Front 14

The Dermal System

Back 14

complex tissue system which makes up the outer layers of a plant. Consists of a cuticle, epidermal cells, stomata, secretory structures and trichomes

Front 15

Cell Theory

Back 15

States that cells determine the shape of the organism. Genes determine cell size, shape and plane of cell diviosn with ultimately decides the form that the plant takes, this is applicable to animals but is problematic for plants.

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Epidermal cells

Back 16

usually only a single layer that divides anticlinally, provides a protective barrier against UV rays, predators, water loss, abrasion, pathogens

Front 17

Cuticle

Back 17

Waxy layer that protects the plant. It also helps prevent water loss and reflect UV radiation. Wax patterns are specific to different plant species

Front 18

Stomata

Back 18

the pores of the plant which are found all around the plant, except in the roots. Consist of two guard cells which control the opening and closing of each stoma in order to exchange gases and water by transpiration

Front 19

Secretory Structures

Back 19

there are many different types of these, for example osmophores which emit flower scent

Front 20

Trichomes

Back 20

are the hairs and scales found on many plants, they have highly variable functions and structures. Their functions include, defense, water absorbtion, frost protection, prevent water loss, collect nutrients, attract pollinators

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Ground Tissues

Back 21

refers to the bulk of the plant body, parenchyma, collenchyma, sclerenchyma

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Parenchyma

Back 22

most abundant tussue, thin walled cells that are usually alive when fully mature, are polyhedral

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Collenchyma

Back 23

simple tissue, usually longer than they are wide, have thickened primary cell walls comprising of alternating layers of cellulose and pectins, this provides strength and flexibility

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Sclerenchyma

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these are dead at maturity and are characterized by thickened secondary cell walls that are impregnated by lignin

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Aerenchyma

Back 25

large air spaces between clusters of parenchyma cells, which are common in plants that spend some or all of their lives submerged, these can arise from cell rupture, enzymes, or star shaped cells

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Lignign

Back 26

a complex polymer that is hard and hydrophobic, this provides structural protection and protection against herbivores

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Fibres

Back 27

long narrow sclerenchyma cells, that usually occur in bundles and are common on or near veins, cotton is an example of a fibres used by humans

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Scereids

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are diverse in shape but have hard, often pitted cell walls, this causes gritiness in pears and feijoas and walnut seed coats

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Monocot Leaf

Back 29

veins run parallel along the length of the blade

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Eudicot Leaf

Back 30

there is a main central midrib and several orders of lateral veins

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Vascular Bundle

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is the site of transport of water and sugar and nutrients in a plant

Front 32

Procambium

Back 32

is meristemic tissue that divides to create the tissues of the vascular system, it dived periclinaly to produce Xylem on the outside and phloem on the outside

Front 33

Xylem

Back 33

a complex tissue which forms continuous pipes that conduct water and mineral from the roots to the shoots, consists of tracheary elements, fibres and parenchyma

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Phloem

Back 34

a complex tissue that transports sugars, hormones and other organic compounds up and down the plant, consists of sieve elements, fibres and parenchyma

Front 35

Protoxylem

Back 35

first formed trachaery elements with hooped or spiral patterns of lignin reinforcement

Front 36

Metaxylem

Back 36

later formed trachaery elements with webbed or pitted pattern of lignin reinforcement, it is much bigger than protoxylem

Front 37

Tracheids

Back 37

type of trachaery elements, these are found in all vascular plants, are long narrow cells which are sealed at the ends, water moves through the pits of the side walls

Front 38

Vessel Elements

Back 38

type of trachaery elements found in flowering plants, are short wide cells which have perforations at the ends, water moves through the perforations and through the pits of the side walls, meaning water moves continuously

Front 39

Seive Elements

Back 39

elongated, highly specialized cells, narrower than trachery elements, the cells are alive at maturity but the nucleus degenerates and they have no vacuole, they only have a primary cell wall

Front 40

Trachaery Elements

Back 40

dead at maturity and have patterns of reinforcement depending on when they were formed

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Sieve Cells

Back 41

found in gymosperms and ferns, the ends of the cells are sealed and the solutes move across cells through pores

Front 42

Sieve Tube Elements

Back 42

found in flowering plants, the ends of the cells have sieve plates, the solutes more through the sieve plates and through the pores

Front 43

Root Tip

Back 43

the top of the root where the development of the root occurs

Front 44

Root Cap

Back 44

is where gravity is percieved by the plant. Consists of parenchyma cells that are continuously being sloughed off and replaced by new cells produced by the root apical meriste. Function is to protect the root apical meristem as the root forces soil particles apart, contains columella cells that contain starch

Front 45

Root Apical Meristem

Back 45

is located immediately above the root cap and divides constantly to produce all the cells in the root system, ferns have a single founder cell but in most plants there are groups of founder cells

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Elongation Zone

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part of the root that responds to gravity, above the root apical meristem, is usually only a few mm long but is responsible for all the growth of the root

Front 47

Maturation Zone

Back 47

region above the elongation zone, and is where all the root hairs and lateral roots are formed

Front 48

Contractile Roots

Back 48

at a certain point in development the roots of some plants such as carrot, contract in length and swell outwards drawing the shoot apex closer to the soil, this serves as a storage organ and protects the shoot from predators and environmental factors such as wind

Front 49

Root Products

Back 49

include alkaloids such as morphine and nicotine. There are 12000 of these in plants which help the plant deter herbivores and have been used but humans as medicine, witchcraft and psychoactive drugs

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Fertilisers

Back 50

vast quanities of fertilizers are applied to agricultural land but less than half gets in the plant, these contribute to air pollution and causes algal bloom in water catchements however the human population is expanding and people need to be fed

Front 51

Soil

Back 51

is a mix of organic and inorganic particles, water and airspace, they can generally be classified as a mix of sand silt and clay. Root elongation and branching pattern vary in different types of soil, depending on their porosity and water content

Front 52

Root Hairs

Back 52

reponsible for uptake of water and minerals, can be as long as 1.3cm and may attain their size within a few hours, they are relatively short lived but are continually replaced as long as the root is growing

Front 53

Soil pH

Back 53

a pH of 5.5 is optimal for the root growth of most plants, lime can be used to increase pH and elemental sulphur can be used to decrease pH, many nutrients are less soluble in alkaline soil and so are less likely to be drained away by drainage water

Front 54

Macronutrients

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Nitrogen, Potassium, Calcium, Magnesium, Phosporus, Sulphur, Silicon

Front 55

Micronutrients

Back 55

Chlorine, Iron, Boron, Manganese, Sodium, Zinc, Copper, Nickel, Moybdenum

Front 56

Monocot Root

Back 56

have tap roots which quickly are replaced by adventitious roots which arise from the base of the stem, they tend to be fibrous and do not grow as deeply but have wide branching angles that provide anchorage

Front 57

Eudicot Root

Back 57

have tap roots that branch into lateral roots and the lateral roots also branch to form a dense network , they grow deeper than moncot roots but bind less firmly to soil particles

Front 58

Apoplastic Pathway

Back 58

water and solutes move along the continuum of cell walls and extracellular spaces

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Symplastic Pathway

Back 59

water and solutes move along the continuum of 'cytosol' they must cross the plasma membrane once, and then can move from cell to cell via the plasmodesmata

Front 60

Transcellular Pathway

Back 60

water and solutes move out of one cell across the cell wall and into the neighbouring cell

Front 61

root bark

Back 61

in woody plant species, the cortex of the root may degenerate leaving only the stele, around with develops a layer of bark, consisits of the periderm and the phloem

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Pericycle

Back 62

the outermost layer of the stele, one layer inwards from the endodermis, this is the origin of lateral roots, periclinal cell divisions lead to the outgrowth of a lateral root with eventually punctures the root surface

Front 63

Starch Statolith Hypothesis

Back 63

theory that starch containing amyloplasts are a plants method of percieving gravity

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Monocot Stem

Back 64

continuous vascular cylinder

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Eudicot Stem

Back 65

ring of vascular bundles

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Gymosperm Stem

Back 66

scattered vascular bundles

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Central Hollow

Back 67

occurs if the pith ruptures, this is useful because hollow structures are stronger than solid structures

Front 68

Why do plants have stems?

Back 68

to help them reach sunlight, grow away from herbivores, to distribute seeds in the wind, to escape anoxia from flooding, providing a transport medium, to make flowers more visible for sexual reproduction

Front 69

Gibberellin

Back 69

plant hormone that promote the elongation of stems, there are more than 125 structurally related giberelllin, they are found all over the plant but are at the highest concentration in immature seeds, produced in shoot and root tips

Front 70

Auxin

Back 70

plant hormone that inhibits the outgrowth of axillary buds, this effect is weaker the farther the buds from the shoot apical meristem

Front 71

Apical Dominance

Back 71

the name of the inhibition of outgroth of axillary buds, it can be overcome by topping the plant, causing the axillary buds to grow out

Front 72

Cytokinin

Back 72

plant hormone that causes axillary buds to branch out even when the shoot apical meristem is present

Front 73

Shoot Apical Meristem

Back 73

occurs at the very tip of the main stem above even the youngest leaf, there is also a shoot apical meristem at the tip of every branch, it is the region of active cell division and also the region in which leaves are initiated. Can be dome shaped or concical or flat, typically they are 100-250µm

Front 74

Tunica

Back 74

the outermost layers of the shoot apical meristem which divide anticlinally

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Corpus

Back 75

the inner layers, which divide anticlinally and periclinally

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Primordium

Back 76

eventually grows out into a leaf, initiated in precise locations on the shoot apical meristem when a cell in one of the tunica layers divides periclinally instead of anticlinally

Front 77

Alternate Phyllotaxis

Back 77

one leaf is produced at every node 180° away from the previous leaf

Front 78

Opposite Phyllotaxis

Back 78

a par of opposite leaves is produced at every node, in parallel files,

Front 79

Decussate Phyllotaxis

Back 79

pairs of opposite leaves are orientated 90° away from the previous pair

Front 80

Whorled Phyllotaxis

Back 80

three or more leaves are produced per node

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Spiral Phyllotaxis

Back 81

successive leaves are 137.5° apart from each other, this is by far the most common arrangement and this angle is considered the 'ideal angle' optimising light interception but minimising self shading

Front 82

Petiole

Back 82

leaf stalk

Front 83

Sessile

Back 83

lacking a leaf stalk

Front 84

Lamina

Back 84

area of the leaf; blade

Front 85

Simple Leaf

Back 85

undivided leaf

Front 86

Compound Leaf

Back 86

blade divided into leaflets, may be pinnate or palmate

Front 87

Adaxial Epidermis

Back 87

upper epidermis, (trichomes, cuticle, epidermal cells, domatia, hydathodes, etc)

Front 88

Palisade Mesophyll

Back 88

long thin columns of photosynthetic cells, they are long and thin to reduce light absorbtion to transmit light onto the lower cells

Front 89

Spongy Mesophyll

Back 89

irregularly shaped photosynthetic cells with large air spaces

Front 90

Abaxial Epidermis

Back 90

lower epidermis, stomata often more abandunt here than on adaxis

Front 91

Growth Rings

Back 91

these are caused by seasonal variation in xylem structure and are often annual, however if climatic changes occur at strange times, false rings can be caused, they are often absent in tropical trees

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Early Wood

Back 92

spring growth, large xylem cells with thin cell walls

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Late Wood

Back 93

summer growth, narrow xylem cells with dense cell walls

Front 94

Secondary Xylem

Back 94

xylem that is formedby division of the vascular cambium, tranports water axially

Front 95

Cork Cambium

Back 95

bark, divides periclinally to produce cork on the outside and phelloderm on the inside

Front 96

Vascular Cambium

Back 96

wood, is a meristem formed from the remaining procambium and the parenchyma between vascular bundles, it has two cell types fusiform initials and ray initials

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Fusiform Initials

Back 97

divides to produce secondary xylem on the inside and secondary phloem on the outside, tall cells elongated axially

Front 98

Ray Initials

Back 98

divides to procude ray cells, small isodiametric cells, storage and radial transport

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Secondary Phloem

Back 99

transports nutrients axially, most is crushed

Front 100

Transverse Section

Back 100

a cross section through 'face' of the object

Front 101

Radial Section

Back 101

a section cut parallel to the long axis, passing through the radius of the axis

Front 102

Ray Cells

Back 102

provide strorage and radial transport

Front 103

Tangential Section

Back 103

longitudinal section in which the cut is perpecndicular to the radius of the object

Front 104

Tyloses

Back 104

blockages that appear in the xylem, making the centre of the trunk non-functional as the tree matures

Front 105

Hardwood

Back 105

comes from angiosperms for example, oak, is high in lignin, consists of vessels elements and tracheids

Front 106

Softwood

Back 106

conifers for example, pine, low in lignins consists of tracheids

Front 107

Phelloderm

Back 107

living parenchyma that is produced by the cork cambium

Front 108

Cork Cells

Back 108

dead cells lined with suberin and wax and is impermeable

Front 109

Lenticels

Back 109

are raised oval areas that create intercellular spaces that allow gas exchange

Front 110

What causes knots in wood?

Back 110

knots are the sight of where a branch was once attached

Front 111

Induction

Back 111

one of four stages of the development of a flower, the plant recieves environmental cues which ultimately lead to flower formation, it is usually the leaves that percieve cues which inform the plant that it is the correct time to flower

Front 112

Evocation

Back 112

one of four stages of the development of a flower, changes in the shoot apical meristem or axillary buds associated with a commitmen to flowering, typically the apical meristem increases in size and its cells increase the rate of mitosis and DNA/RNA synthesis

Front 113

Organogenesis

Back 113

one of four stages of the development of a flower, the formation of floral organs, usually the outermost organs are initiated first so the order of the initiation is commonly sepals-->petals-->stamens-->carpel

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Annual

Back 114

plant that germinates, grows, flowers and dies with one year

Front 115

Biennial

Back 115

plant that flowers in the second year and then dies

Front 116

Perennial

Back 116

flowers regularly, often annually, over many years, may take some years before the first flowers are formed, need to be revernalized every winter

Front 117

Monocarpic

Back 117

grows vegetatively for many years then flowers once and dies

Front 118

Photoperiodic Plants

Back 118

a plant that flowering in controlled by day lengh meaning it can time reproduction to aviod mid-summer drought, autumn cold or late spring frosts

Front 119

Short Day Plants

Back 119

plants that must be exposed to light periods shorter than a critical duration for flowering to occur, they usually flower in autumn and are most common in tropical regions

Front 120

Long Day Plants

Back 120

plants that must be exposed to light periods longer than a critical duration for flowering to occur; they flower in spring or summer and are most common in temperate regions

Front 121

Day Neutral Plants

Back 121

plants that flower without regard to daylength, most species fall into this category

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Obligate requirement

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the correct photoperiod is essential for flowering, less than 1% of plants fall into this category

Front 123

Quanitative Requirement

Back 123

the correct photoperiod reduces the time to flowering and may increase the numbers of flowers, but plants will eventually flower anyway, most plants fall into this category

Front 124

Night Length

Back 124

experiments have shown that it Is night length rather than day length that is critical for photoperiodic plants

Front 125

Night-break Effect

Back 125

this is when white light interupts a long night, short day plants do not flower but long day plants do

Front 126

Florigen

Back 126

universal plant hormone that is thought to stimulate flower growth even in plants not in the correct photoperiod

Front 127

Vernalization

Back 127

requirement for low temperature (between-1-9°C) treatment before plants can be induced to initiate flowers

Front 128

Devernalization

Back 128

reversal of vernalization by 25-50°C temperatures, the longer the plant has been chilled the more difficult it is to reverse

Front 129

Vernalin

Back 129

hormone that is thought to transmit vernalized conditions to all new tissues

Front 130

Germination

Back 130

promoted by giberellens which increase growth of the radical, stimulates release of hydrolytic enzymes and overrides the requirement for cold, long days etc.

Front 131

Root and Shoot Growth

Back 131

regulated by ratio of auxin:cytokinin

Front 132

Ethylene

Back 132

gaseous hormone associated with fruit ripening

Front 133

Absiscic Acid

Back 133

a single compound that plays a part in several inhibitory roles

Front 134

Fruit Development

Back 134

parthenoscarpic fruit formed when carpel given auxin

Front 135

Fruit Ripening

Back 135

stimulated by ethylene with is generated during ripening

Front 136

Senescence

Back 136

(aging) triggered by minute quantities of ethylene

Front 137

Plant Horomones

Back 137

differ from animal hormones. The same compound may be syntheised at different locations on the plant, may act in the same tissue or cell where they are produced, have multiple functions, often inhibitory, active at low concentrations in all processes of growth and development

Front 138

Dormancy

Back 138

stimulated by abscisic acid in buds and seeds

Front 139

Xerophytes

Back 139

plants adapted to live in dry conditions, most have a thick waxy cuticle, sunken stomata, small leaves, many trichomes,

Front 140

Mesophytes

Back 140

plants that grow in fairly average conditions

Front 141

Hydrophytes

Back 141

aquatic plants that have adapted to living in aquatic conditions, most have little if any cuticle, stomata only appear on the adaxial side of the leaf, arenchyma are often present,

Front 142

Casparian Strip

Back 142

hydrophobic strip of suberin and/or lignin in the transverse cells walls of the endodermis which blocks the appoplastic movement of solutes into the stele, meaning the solutions must cross the cell wall allowing selective uptake of nutrients

Front 143

Domatia

Back 143

serve to house mites that pray on herbivorous mites that will eat the plant

Front 144

Protoplast

Back 144

spherical cell formed when the cell wall of a parenchyma cell is dissovled by enzymes

Front 145

Primary Cell Wall

Back 145

layed down while the cell is still growing, a mixture of pectin and water

Front 146

gravitropism

Back 146

a plants response to gravity, roots are positvely gravitrophic, stems are negatively gravitrophic

Front 147

Quiescent centre

Back 147

part of the root apical meristem that divides very infrequently, these cells divide if the plant is under stress and needs more cell division

Front 148

Water availibiilty

Back 148

if there is a lot of water, root growth is minimal, if there is little water, roots will grow quicker in order to find a secure source of water

Front 149

method of obtaining mineral from soil

Back 149

roots obtain their minerals from the soil solution surrounding the soil particles through the root hairs by diffusion, Soil particles are usually negatively charged, cations absorbs them while anions do not. Root hairs can pump protons into the soil solution, which can replace the cations on the soil surface, so that the cations are available for absorbtion. if the root hairs become damaged, the plant may not be able to secure sufficent mineral nutrition

Front 150

hydroponics

Back 150

process of growing plants without soil and selected nutrients in order to study nutrient uptake and effects in plants

Front 151

root cortex

Back 151

comprises of ground tissue in the root, water and minerals absrobed by the root hairs, travel through here to the steel

Front 152

steel

Back 152

comprises of xylem and phloem in the root

Front 153

plasmodesmata

Back 153

microscopic pathways transverse to the cell walls of plants that allows transport

Front 154

shoot cortex

Back 154

peripheral to the vascular bundle, comprises of parenchyma cells, collenchyma, starch, crystals, glands, resins and sclerids may also be found

Front 155

pith

Back 155

central region of the stem, comprises of parenchyma cells, collenchyma, starch, crystals, glands, resins and sclerids may also be found

Front 156

anticlinal

Back 156

cell division at right angle to the surface of the parent cell

Front 157

periclinal

Back 157

cell division parallel to the surface of the parent cell

Front 158

parastichies

Back 158

are non existant spirals of a leaf, unrelated to the order of leaf initiation

Front 159

Foliar Butress

Back 159

product of periclinal cell division of cells in the tunica layer, appears as a bulge on the apical meristem which elongates vertically, in eudicots in bends over the shoot apical meristem, in monocots it wraps around the shoot apical meristem

Front 160

Leaf Air Spaces

Back 160

formed by the rupture of spongey mesophyl cells that has stopped growing and serve to increasethe light absorbed by the spongey mesophyll by reflecting the light internally, they also provide oxygen for respiration and carbon dioxide for photosynthesis

Front 161

trunk bark

Back 161

consists of the periderm, cortex and phloem, as the trunk expands more bark is formed, the outer bark may shed

Front 162

anthesis

Back 162

one of four stages of the development of a flower, when the flower opens