Biology 152 - Exam Ii

Front 1

What are the four traits that Charophytes (plant's closest relative) and Plants have in common which distinguish them from other things (algae...etc.)?

Back 1

1) Rosette-shaped cellulose-synthesizing complexes
2) Peroxisome enzymes
3) Flagellated sperm
4) Formation of phragmoplast

Front 2

Who are plant's closest relatives?

Back 2

Charophytes

Front 3

What distinguishes charophytes (plant's closest relative) from plants?

Back 3

Plants are terrestrial.

Front 4

What are the four derived characteristics of plants?

Back 4

1) Alternation of generations
2) Multicellular gametangia
3) Apical meristems
4) Sporopollenin

Front 5

What is the significance of the "phragmoplast"?

Back 5

Shared characteristic of charophytes and plants.
A group of microtubules that forms between daughter nuclei of a dividing cell which directs the cell plate formation.

Front 6

What is the function of "peroxisome enzymes"?

Back 6

Help minimize the loss of organic products as a result of photorespiration.

Front 7

What are the two generations that alternate in plants?

Back 7

Gametophyte (n)
Sporophyte (2n)

Front 8

Starting with the gametophyte, what is the general life cycle of plants? (5 steps)

Back 8

1) Gametophyte produces haploid gametes by mitosis
2) Two gametes unite (fertilization) and form a diploid zygote (2n)
3) Zygote develops into multicellular diploid sporophyte (2n)
4) Sporophyte produces haploid spores (n) by meiosis
5) Spores develop into multicellular haploid gametophytes (n) through mitosis

Front 9

What are some advantages to being aquatic (charophytes)?

Back 9

- Abundance of water
- Water is a buffer
- Structural support
- Reproduction is easy

Front 10

What are some disadvantages to being aquatic (charophytes)?

Back 10

- Dilution of nutrients
- Light is not as available
- Limited O2 and CO2
- No control of movement

Front 11

What are some advantages to being terrestrial (plants)?

Back 11

- More light available
- Minerals are more abundant (not diluted)
- O2 and CO2 are not limiting
- Stability in ground / anchor
- No competition initially

Front 12

What are some disadvantages to being terrestrial (plants)?

Back 12

- Extreme environments
- H2O is limiting
- Reproduction is more difficult
- Herbivores
- Lack of structural support
- UV radiation damage

Front 13

Which are the nonvascular plants?

Back 13

Bryophytes (liverworts, hornworts, mosses)

Front 14

What can vascular plants be further divided into?

Back 14

Seedless (lycophytes and pterophytes)
With seeds (gymnosperms and angiosperms)

Front 15

What kind of seedless vascular plants are there?

Back 15

Lycophytes (club mosses, spike mosses, quillworts)
Pterophytes (ferns, horsetails...)

Front 16

What is the function of sporopollenin in plants?

Back 16

Makes walls of plant spores tough and resistant to harsh environments; protects from desiccation (drying out).

Front 17

What is the function of the cuticle?

Back 17

Waxy, protective layer that prevents excess water loss from epidermis.

Front 18

What is the function of lignin?

Back 18

Provides structural support in terrestrial species.

Front 19

What distinguishes bryophytes from other land plants?

Back 19

No vascular system; most similar to ancestral plants; gametophyte is dominant (not sporophyte).

Front 20

What are apical meristems?

Back 20

Localized regions of cell division at the tips of shoots and roots that are undifferentiated.

Front 21

What is the function of vascular tissue?

Back 21

Cells that are joined into tubes that transport water and nutrients through the plant body.

Front 22

What is the intermediary step between bryophyte spores and their dominant phase (gametophyte)?

Back 22

Protonemata (n) - a mass of green branched, one cell thick filaments that grow from spores and buds to produce gametophytes.

Front 23

Bryophyte (moss) gametophytes can be male or female... What are they called? How do they fertilize?

Back 23

Male - Antheridia
Female - Archegonia
Sperm released from antheridia swim through a film of moisture to reach the egg.

Front 24

Since bryophytes do not have roots, what do they rely on to anchor the gametophyte?

Back 24

Rhizoids

Front 25

What do the seta and capsule make up in a bryophyte (moss)?

Back 25

Sporophyte

Front 26

Why do mosses / bryophytes require a moist habitat?

Back 26

Fertilization requires a film of water in order for sperm to swim to egg.

Front 27

At the end of the sporophyte capsule in bryophytes / mosses, there is what structure which allows for the slow release of spores?

Back 27

Peristome

Front 28

What is the function of stomata?

Back 28

Specialized pores which allow the exchange of CO2 and O2; also the route through which water evaporates from the sporophyte.

Front 29

What is the origin of "peat"? What can it be used for?

Back 29

Partially decayed organic material; fuel source (400 billion tons of C is sequestered).

Front 30

How much Carbon do humans release per year?

Back 30

7-8 billion tons per year.

Front 31

What structures do vascular plants specifically have?

Back 31

Xylem, Phloem, Leaves, Roots

Front 32

What is the dominant generation in vascular plants?

Back 32

Sporophyte

Front 33

What is the difference between the terms homosporous and heterosporous?

Back 33

Homosporous = one type of sporangium = one spore --> bisexual gametophyte
Heterosporous = two types of sporangia = differentiation of spores (megaspores, f, and microspores, m)

Front 34

What are the five stages in the life cycle for a fern (seedless vascular plant)?

Back 34

1) Sporangia release spores (homosporous)
2) Gametophyte produces eggs or sperm
3) Sperm use flagella to swim from the antheridia to eggs in the archegonia for fertilization
4) Zygote develops into a new sporophyte
5) On underside of sporophyte's reproductive leaves are spots called sori made up of a cluster of sporangia.

Front 35

Where are the sporangium (spore producing organs) located on a fern?

Back 35

On the underside of the sporophyte's reproductive leaves in spots called sori (each sorus is a cluster of sporangia).

Front 36

Why did the gametophyte evolve to be less dominant and a smaller structure that is enclosed?

Back 36

To protect the gametes from UV radiation and other harm.

Front 37

The club mosses, spike mosses, and quillworts are what kind of plants?

Back 37

Lycophytes: seedless vascular plants

Front 38

The ferns, whisk ferns and horsetails represent which kind of plants?

Back 38

Pterophytes (seedless vascular plants)

Front 39

The ratio of CO2 in the atmosphere 600-400 mya was very high, what explained the crashing to today's level around 350 mya?

Back 39

CO2 was being incorporated into plants
- evolution of vascular tissue, roots, and leaves increased the rate of photosynthesis
- coal was made by build up of carbon in plants under lots of pressure
- during Carboniferous period

Front 40

When the rate of CO2 dropped due to increased photosynthesis, what also occurred in the atmosphere? What effect did this have?

Back 40

O2 increased in atmosphere
Led to huge insects

Front 41

What is a seed? What did seeds replace?

Back 41

An embryo packaged with a supply of nutrients inside a protective coat; spores.

Front 42

What are the two kinds of seed plants? How are they distinguished from one another?

Back 42

Gymnosperms = naked seed plants
Angiosperms = ovaries / flowers and fruits

Front 43

What three components make up the ovule?

Back 43

Megosporangium, megaspore, integument

Front 44

What is the male gametophyte for seed plants?

Back 44

Pollen grain.

Front 45

What forms the hard seed coat?

Back 45

The integument becomes the seed coat.

Front 46

What polymer protects the pollen grain / male gametophyte?

Back 46

Sporopollenin.

Front 47

Gymnosperms show the evolutionary transition to non-motile spores. How do they compensate for this?

Back 47

The pollen grains are able to travel by the wind or animals, eliminating the need to swim via water.

Front 48

What is the purpose of the pollen tube?

Back 48

It discharges the sperm from the pollen grain into the egg.

Front 49

What is the opening in the integument through which the pollen grain enters to fertilize the egg?

Back 49

Micropyle

Front 50

What are five characteristics of seed plants?

Back 50

1) Reduced gametophytes
2) Heterosporous (two kinds of sporangia/spores)
3) Ovules (containing female gametophyte)
4) Pollen (containing male gametophyte)
5) Seeds
4)

Front 51

Why are seeds more advantageous than spores?

Back 51

- Seeds are more protected than spores (higher survival)
- Independent and dispensable from parent

Front 52

What are the three components of a seed? From what do they originate from? Haploid or diploid?

Back 52

- Integument (protective coat from parent sporophyte) (2n)
- Food supply (from parent gametophyte) (n)
- Embryo (new sporophyte) (2n)

Front 53

What are the four kinds of gymnosperms?

Back 53

1) Conifers (biggest phylum)
2) Cycads (2nd biggest phylum)
3) Ginkgo
4) Gnetophytes

Front 54

What was the transitional species between seedless plants and seed plants that was heterosporous, no seeds, very developed vascular system

Back 54

Progymnosperm (380 mya)

Front 55

What are the four main structural parts of a flowering plant?

Back 55

1) Sepal
2) Petal
3) Stamen (Anther & Filament)
4) Carpel (Stigma, Style, & Ovary)

Front 56

What is a fruit?

Back 56

Mature ovary.

Front 57

What does the stamen develop into in angiosperms?

Back 57

Pollen grain.

Front 58

What does the carpel develop into in angiosperms?

Back 58

Female gametophytes (embryo sac)

Front 59

Which part of the flower receives the pollen? Which part connects the stigma to the ovary? Which part contains the ovules?

Back 59

The stigma of the carpel. Style. Ovary.

Front 60

What is meant by double fertilization?

Back 60

One sperm fertilizes the egg to form the zygote.
One sperm produces a triploid cell (2 nuclei and 1 sperm)

Front 61

What distinguishes Monocots from Dicots?

Back 61

Monocots (vs. Dicots):
- One cotyledon (vs. two)
- Parallel veins (vs. netlike)
- Vascular tissue scattered in stem (vs. in rings)
- Root system is fibrous, no main root (vs. taproot, main root)
- Pollen grain has one opening (vs. three openings)
- Floral organs in multiples of 3 (vs. 4 or 5)

Front 62

Spores are produced after which step? What do they produce?

Back 62

After meiosis; give rise to gametophytes.

Front 63

What are the three general components/organs of plants?

Back 63

Roots (root system)
Stems & Leaves (shoot system)

Front 64

Roots have evolved in almost all _____ plants.

Back 64

Vascular

Front 65

What is the purpose of roots?

Back 65

Acquire water and minerals via root hairs; anchor plants; store carbohydrates.

Front 66

What are some modified roots?

Back 66

Prop roots, Storage roots, Fibrous roots, Aerial roots, Pneumophores (obtain O2 in wet settings by sticking out of H2O), Buttress roots

Front 67

Single, elongated cells that absorb water and minerals by increasing surface area, are called what?

Back 67

Root Hairs

Front 68

Where does primary growth occur?

Back 68

Apical meristems - localized regions of cell growth at tips of shoots and roots.

Front 69

What are the two modified stems? How are they distinguished?

Back 69

Rhizomes = below ground stems
Stolons = above ground stems

Front 70

What is "vegetative growth"?

Back 70

Production of non-reproductive leaves, stems and roots.

Front 71

What is the function of leaves?

Back 71

Increase surface area of plant which aids in photosynthesis.

Front 72

What are the three kinds of leaf growth?

Back 72

Simple leaf (single undivided blade)
Compound leaf (blade of multiple leaflets)
Double Compound leaf (each leaflet is divided into smaller leaflets)

Front 73

What are the hairlike outgrowths of the shoot epidermis that reduce water loss and reflect excess light; also provide defense against insects with toxic chemicals?

Back 73

Trichomes

Front 74

What kind of modified leaves are there?

Back 74

- Tendrils (support for pea plants)
- Spines (cacti)
- Storage leaves (water)
- Reproductive leaves (grow and fall off to form new plants)
- Bracts (poinsettia)

Front 75

What are the three layers of tissue?

Back 75

1) Dermal tissue - outer protective covering
2) Ground tissue - inside of plant
3) Vascular tissue - transport minerals / water / sugars (xylem & phloem)

Front 76

What tissue replaces the epidermis in woody plants?

Back 76

Periderm

Front 77

What is the cell wall made of? What is its purpose?

Back 77

Made of cellulose; provides rigidity and strength.

Front 78

What is the space between cell walls which contains pectin and pectic acid?

Back 78

Middle lemella

Front 79

What are the five types of plant cells?

Back 79

1) Parenchyma cells
2) Collenchyma cells
3) Sclerenchyma cells
4) Xylem
5) Phloem

Front 80

Which kind of plant cells have a large central vacuole, is engaged in many metabolic functions, and has the ability to differentiate into other cells?

Back 80

Parenchyma cells

Front 81

Which kind of plant cells have a thicker primary cell wall that varies in thickness giving the plant flexibility and stability? Plant it's in?

Back 81

Collenchyma cells; celery

Front 82

Which kind of plant cells are used for support due to their unusually thick cell walls; they are dead upon maturing...?

Back 82

Sclerenchyma cells

Front 83

What are the two kinds of sclerenchyma cells? What are they used for?

Back 83

Schlereids (hardness of nutshells, pears)
Fibers (in linens)

Front 84

Which kind of plant cells are used for movement of water and minerals?

Back 84

Xylem

Front 85

What two kinds of cells make up the xylem?

Back 85

Tracheids (narrower pipes to move water from roots to rest of plant)
Vessels (wider with perforation plate on one end)

Front 86

Through which structure do the tracheids and vessels of the xylem pass water horizontally?

Back 86

Pits (areas where there is only primary cell wall)

Front 87

Which plant cells are dead at functional maturity?

Back 87

Sclerenchyma cells and Xylem

Front 88

Which type of plant cells are responsible for the movement of organic nutrients (sugars, amino acids, etc.)?

Back 88

Phloem

Front 89

What two kinds of cells are in the phloem?

Back 89

Sieve cells (facilitate flow of liquid from cell to cell)
Companion cells (non-conducting)

Front 90

What structure allows the movement of sugars between phloem cells?

Back 90

Plasmodesmata (connected by membrane)

Front 91

What are the areas in plants that are perpetually embryonic tissues? What two kinds are there?

Back 91

Meristems: apical (at top of plant, produces primary growth) or lateral (along stem, secondary growth)

Front 92

What two structures make up the lateral meristems (secondary growth)?

Back 92

Vascular cambium
Cork cambium

Front 93

What is the function of the vascular cambium?

Back 93

Adds layers of secondary xylem and phloem.

Front 94

What is the function of the cork cambium?

Back 94

Replaces epidermis with periderm.

Front 95

What is the stuff external to the vascular system (stem/trunk) called?

Back 95

Cortex

Front 96

What is the structure that includes the vascular tissue (xylem and phloem) within the endodermis of a root or stem? (Circular core of roots)

Back 96

Stele

Front 97

Which of the vascular tissues grows inwards? Which grows outward? (from vascular cambium)

Back 97

Inward = xylem
Outward = phloem

Front 98

What is the internal core inside of the xylem called?

Back 98

Pith

Front 99

What makes up the bark?

Back 99

Secondary Phloem and Periderm

Front 100

What are the two kinds of mesophyll (ground tissue) cells in a leaf?

Back 100

Palisade cells
Spongy cells

Front 101

Why do the spongy cells have so many openings between them?

Back 101

For gas exchange (take up CO2, release O2)

Front 102

Which cells focus the light on the chloroplasts?

Back 102

Palisade cells

Front 103

What's the difference between microphylls and megaphylls?

Back 103

Microphyll = small, spine-shaped leaves with single strand of vascular tissue
Megaphyll = highly branched vascular systems (greater photosynthetic productivity)

Front 104

When did plants first appear? Plants with leaves?

Back 104

Plants = 475 mya
Leaves = 380 mya (coincided with drop in CO2 concentration)

Front 105

In which tissue are chloroplasts located?

Back 105

Mesophyll - tissue inside of leaf

Front 106

Where does photosynthesis occur?

Back 106

In chloroplasts in stacks of thylakoids in grana.

Front 107

In the light reactions what are the inputs and outputs?

Back 107

Inputs = H2O, light, NADP+, ADP
Outputs = O2, ATP, NADPH

Front 108

In the dark reactions (Calvin Cycle) what are the inputs and outputs?

Back 108

Inputs = CO2, ATP, NADPH, RuBP
Outputs = Sugars, NADP+, ADP

Front 109

Where do the light reactions occur? Dark reactions?

Back 109

Light = thylakoids
Dark = stroma (dense fluid in chloroplasts surrounding the thylakoid membranes)

Front 110

What do the light reactions do?

Back 110

Converts solar energy to chemical energy (ATP).

Front 111

What do the dark reactions (Calvin Cycle) do?

Back 111

Produces sugars only with help from NADPH and ATP that are generated during the light reactions.

Front 112

What is the most abundant protein? What is it's job?

Back 112

Rubisco - fixes CO2

Front 113

What are the three basic steps of the Calvin Cycle?

Back 113

1) Carbon fixation (3 CO2 + Rubisco --> 3-phosphoglycerate)
2) Reduction (form G3P, one released as sugar)
3) Regeneration of CO2 acceptor (RuBP via 5 G3P)

Front 114

When does photorespiration occur?

Back 114

As the concentration of O2 increases the rate of photosynthesis decreases and photorespiration increases.

Front 115

What molecule is responsible for photorespiration occurring? Why?

Back 115

Rubisco is reactive with O2 as well as CO2; evolved back when O2 had a low concentration, so it was not necessary to be exclusive of O2

Front 116

What happens when photorespiration is occurring?

Back 116

Consumes ATP, produces no sugars, decreases photosynthetic output.

Front 117

Which enzyme can be utilized instead of rubisco and is useful due to its ability to preferentially use CO2 and not O2?

Back 117

PEP Carboxylase (adds PEP to CO2 to make oxaloacetate)

Front 118

When PEP Carboxylase adds PEP to CO2 what forms?

Back 118

Oxaloacetate --> Malate --> ...

Front 119

The malate produced in the mesophyll cells (by PEP --> Oxaloacetate) is sent where to do what?

Back 119

Bundle-Sheath Cells to enter Calvin Cycle (brings CO2)

Front 120

The sugars made by the Calvin Cycle are released to where?

Back 120

Vascular tissue / veins (for transport)

Front 121

What distinguishes a C3 plant?

Back 121

Stomates close on hot, dry days to conserve water; decreases the photosynthetic potential.

Front 122

What distinguishes a C4 plant?

Back 122

Alternate mode of carbon fixation; bundle sheath and mesophyll cells help to concentrate CO2 in Calvin Cycle; increases productivity in hot, dry areas.

Front 123

In which kind of plants is the alternative PEP Carboxylase method utilized?

Back 123

CAM and C4 plants (helps them work in hot, dry areas)

Front 124

What distinguishes CAM plants?

Back 124

- Alternate mode of carbon fixation
- Open stomates at night (C4 Cycle / CO2 fixation)
- Close stomates during day and close out O2 (Calvin Cycle / Sugar production)

Front 125

Where are CAM plants usually found?

Back 125

Harsh environments (hot / dry conditions) (deserts, succulent plants)

Front 126

Why do C4 plants have an advantage in hot, dry conditions?

Back 126

- No (or little) photorespiration
- PEP carboxylase scavenges CO2 at low concentrations so stoma closure has little effect
- Calvin Cycle runs to use all CO2
- Increased nitrogen efficiency

Front 127

When do C3 plants have an advantage over C4 plants?

Back 127

Lower leaf temperatures = higher net rate of photosynthesis
(as it gets warmer, C3 plants close stomates, slowing photosynthesis)

Front 128

When do C4 plants have an advantage over C3 plants?

Back 128

Higher leaf temperature, higher light intensities.

Front 129

Where are most C4 plants found?

Back 129

Tropical regions

Front 130

What does primary growth produce?

Back 130

Epidermis, ground tissue, and vascular tissue

Front 131

In the roots, how can the stele be described?

Back 131

Vascular cylinder

Front 132

Where does secondary growth arise from?

Back 132

Lateral meristems (vascular cambium and cork cambium)

Front 133

What is the nonfunctional xylem wood in the center of the trunk called?

Back 133

Heartwood

Front 134

What is the layer around the heartwood called?

Back 134

Sapwood

Front 135

What layers make up the secondary xylem?

Back 135

Hearwood, Sapwood (from vascular cambium)

Front 136

How do plant cells divide?

Back 136

Mitotically by putting down a cell plate

Front 137

What is the function of vacuoles?

Back 137

Take in water and hold it; expands cell

Front 138

Why do plants have to asymmetrically divide?

Back 138

So they can determine polarity / directionality

Front 139

What determines where the cell plate goes?

Back 139

Direction of the bands of microtubules around the nuclei (microfibrils align themselves according to direction of microtubules which determines which way the cell expands).

Front 140

In which kind of mutant is the orientation of microtubules random (thus generating cells growing in all directions)?

Back 140

Fass mutants

Front 141

In which kind of mutant is the establishment of polarity defective?

Back 141

Gnom

Front 142

What are homeotic genes? What are the two we studied?

Back 142

Genes that regulate development
- KNOTTED-1
- GLABRA-2

Front 143

What is the homeotic gene which is involved in leaf morphology?

Back 143

Knotted-1

Front 144

What is the homeotic gene which is involved in root hair distribution?

Back 144

Glabra-2

Front 145

From where do plants acquire water and minerals?

Back 145

Roots

Front 146

From where do plants acquire energy/light and CO2?

Back 146

Leaves

Front 147

What is the main factor influencing the level of transpiration in a plant?

Back 147

Water availability

Front 148

What is the LAI? Value for a young plant? Common values for mature plants?

Back 148

Leaf Area Index = ratio of area of leaves per area of ground
- Young: <1
- Mature: 5-7

Front 149

What would be likely to happen if the Leaf Area Index (LAI) value was greater than 7?

Back 149

More respiration would be occurring than photosynthesis; plant would self-prune to decrease the LAI.

Front 150

What are mycorrhizae? What do mycorrhizae do for a plant?

Back 150

Fungi that has a symbiotic relationship with plant which helps plants acquire water and nutrients in the roots.

Front 151

What generates a voltage gradient for active transport in plants?

Back 151

Proton pump

Front 152

How does the cell move H+ from the cytoplasm out of the cell to the extracellular fluid?

Back 152

ATP Hydrolysis which generates an EMF

Front 153

Why do cells move H+ to the extracellular fluid?

Back 153

Allows the cell to transport other sugars/ions/things into the cell via the EMF and transport proteins.

Front 154

In what way does water prefer to flow?

Back 154

From High-water potential to Low-water potential (low solute --> high solute)

Front 155

What makes up the "water potential"?

Back 155

Solute concentration and physical pressure (of cell wall, etc).

Front 156

What is the term for the movement of water across a membrane?

Back 156

Osmosis

Front 157

How can the water potential be lowered?

Back 157

Addition of solutes

Front 158

What is the water potential equation?

Back 158

ψ (w) = ψ (s) + ψ (p)
water potential = solute potential (always negative) + pressure potential (pos. or neg.)

Front 159

When the pressure potential is 0, what does the cell look like? Why?

Back 159

Flaccid - membrane is not pushed up to the cell wall

Front 160

What is the solute potential proportional to?

Back 160

Molarity (0.1M = -0.23 MPa)

Front 161

What is happening in a plasmolyzed cell?

Back 161

Water is leaving the cell and the membrane is trying to come in to try to stop the water loss.

Front 162

What is the normal state of a plant cell?

Back 162

Turgid - water is trying to enter the cell, cell wall is up against the membrane, cell wall i strong and rigid

Front 163

What is loss of turgidity called in a plant cell?

Back 163

Wilting

Front 164

Pure water has a water potential of what? When there is a solute in a solution, how does this affect the solute potential?

Back 164

Pure water = 0 MPa
Solute solution = negative MPa

Front 165

How do plants move from cell to cell without crossing the membranes?

Back 165

Via plasmadesmata (a continuous membrane connection with cytosol)

Front 166

What is the symplastic route of movement between plant cells?

Back 166

Crossing between cells connected by plasmadesmata.

Front 167

What is the route that crosses cell membranes and walls when moving from cell to cell?

Back 167

Apoplastic route

Front 168

Which route goes through the symplast and apoplast?

Back 168

Transmembrane route

Front 169

What is the name of the barrier in the cell wall that prevents movement of water and nutrients between cells?

Back 169

Casparian Strip

Front 170

How do nutrients and water enter the stele if there is a Casparian Strip preventing their movement?

Back 170

Must cross a selectively permeable barrier by entering the internal symplastic route.

Front 171

What are the proteins that facilitate water movement? What is their purpose?

Back 171

Aquaporins - speed up the rate of water crossing the phospholipid bilayer

Front 172

What is bulk flow?

Back 172

Long-distance movement of water driven by pressure, which is much faster than diffusion or active transport.

Front 173

What can explain upward transport of water in a plant up to one meter high?

Back 173

Root Pressure

Front 174

What are the openings on leaves (modified pores) that allows water to escape by guttation due to root pressure?

Back 174

Hydathodes

Front 175

What is the term for water leaving the tips of leaves via the hydathodes (due to root pressure)?

Back 175

Guttation

Front 176

What explains water movement in a plant higher than 1m?

Back 176

Water potential (high to low)
(gradient from high to low, roots to leaves)

Front 177

What does cohesion refer to in regards to water movement?

Back 177

Water molecules stick together in a column of water.

Front 178

What does adhesion refer to in regards to water movement?

Back 178

Water molecules stick to the cell wall to fight against gravity.

Front 179

What state is water in within plants?

Back 179

Liquid in plant, turns to gas when it reaches the stoma to evaporate.

Front 180

What is cavitation? What does it result in?

Back 180

Cavitation is the act of forming an embolism, an air pocket, which prevents the movement of water.

Front 181

How do plants bypass embolisms (air pockets which prevent water movement)?

Back 181

Via pits (openings in the cell wall) which allows water to bypass blockages.

Front 182

When guard cells accumulate K+, what happens?

Back 182

Stomata open

Front 183

What is the structure of a stoma (plural stomata)?

Back 183

Two guard cells

Front 184

What four cues influences stomates opening/closing?

Back 184

1) Light (triggers opening)
2) CO2 depletion
3) Internal clock (usually open during day)
4) ABA hormone signals from roots to tell stomates to close when water levels are low

Front 185

When the stoma is open, guard cells are _____.
When the stoma is closed, guard cells are _____.

Back 185

Open = turgid
Closed = flaccid

Front 186

Organic compounds are produced in ____ and are transported to ____.

Back 186

Sources
Sinks

Front 187

How do organic compounds get transported?

Back 187

Active transport: H+ pump (produces gradient) and cotransport (of sugar molecules with H+)

Front 188

What are the four steps of the pressure-flow hypothesis?

Back 188

1) Loading of sugar from source cell (leaf) into phloem (sieve tube)
2) Uptake of water into sieve tube; attempts to dilute
3) Unloading of sugar into sink cell (storage root)
4) H20 recycled (into xylem)

Front 189

How do phloem and xylem differ in the direction of transport?

Back 189

Xylem = unidirectional (from roots to leaves)
Phloem = bidirectional

Front 190

What proved that sugar concentration is higher in sieve tubes closer to sugar sources?

Back 190

Aphids which feed via stylets (stick into phloem and feed on sugar); helpful for measuring concentration of sucrose.

Front 191

Why can xylem transport water and minerals with dead cells but phloem requires living cells?

Back 191

-Water is moved along a gradient of water potential by tension in xylem (does not need to be alive).
-Phloem sap requires active movement of sugar to concentrate it

Front 192

What do viral movement proteins influence?

Back 192

Size of the plasmadesmata (want it to be larger to allow viral RNA to pass between cells)

Front 193

Where do plant viruses move?

Back 193

In phloem (prefer live cells to dead xylem cells)

Front 194

What four components make up the composition of soil?

Back 194

- Sand (large)
- Silt (small)
- Clay (very small)
- Humus (organic matter)

Front 195

Which component of soil holds the least amount of water?

Back 195

Sand (very porous)

Front 196

Although clay can hold a lot of water, why might this be a bad thing?

Back 196

Does not allow for flow of water.

Front 197

What is the best composition of soil texture?

Back 197

1/3 of each (sand, silt, clay) approximately

Front 198

What is humus?

Back 198

Remains of dead organisms and other organic matter which is resistant to decomposition; stable and long-lived.

Front 199

What are the layers of soil called?

Back 199

Horizons (A, B, C)

Front 200

What is topsoil? Where is it fond?

Back 200

A mixture of broken-down rock, living organisms, and humus; Horizon A.
(Water and wind erosion remove considerable amounts)

Front 201

What is the best kind of soil?

Back 201

Loam (most fertile, has a roughly equivalent amount of each)

Front 202

What charge do soil particles have? Why is this significant?

Back 202

Negative charged at surface; attract positive ions (cations) like K+, Cu2+, Mg2+, Ca2+, H+

Front 203

What is the CEC?

Back 203

Cation Exchange Capacity - different soils have differing abilities to attract/give up these cations depending on the number of cation adhesion sites and pH.

Front 204

How does cation exchange occur?

Back 204

Root hairs release H+ from H2O; H+ ions are attracted to negative soil particles, bumping off mineral cations which are then absorbed by root hairs.

Front 205

Which kind of ions are most susceptible to leeching?

Back 205

Anions because cations are attracted to soil particles; anions sink through horizons and bed rock to the ground water when there is a lot of water in the soil.

Front 206

Why must sand be irrigated way more often than a good soil like silt loam?

Back 206

Sand can hold 0.7 inches of water
Silt loam can hold 2.5 inches of water
(On hot days, can lose up to 0.3 inches)

Front 207

What is tillage used for?

Back 207

Controlling weeds

Front 208

What are negative consequences of tilling?

Back 208

Disrupts soil (roots are disturbed that hold soil in place leading to increased runoff and erosion)
Compaction (soil particles are pressed together, reducing pore space between them, reduces water and nutrient absorption and slows gas exchange and root growth)

Front 209

What kind of experiments are used to determine what minerals are needed for plants?

Back 209

Hydroponic growth (grow in water containing various minerals/nutrients, no soil)

Front 210

What are the macro-nutrients plants require?

Back 210

C, H, O, N, K, Ca, Mg, P, S

Front 211

What are the micro-nutrients plants require?

Back 211

Cl, Fe, Mn, B, Zn, Cu, Ni, MoO4

Front 212

Which nutrients/elements are required for 96% of the plant (organic compounds)

Back 212

C, H, O

Front 213

Which nutrients/elements are required for amino acids specifically?

Back 213

N, S

Front 214

Which nutrient/element is required for regulation of stomates?

Back 214

K

Front 215

Which nutrient/element is required for integrity of the cell wall?

Back 215

Ca

Front 216

Which nutrients/elements are required for chlorophyll?

Back 216

Mg, B, Zn

Front 217

Which nutrients/elements are required for photosynthesis specifically?

Back 217

Cl, Mn

Front 218

Which nutrient/element is required for energy / ATP?

Back 218

P

Front 219

What can cause a deficiency in a plant?

Back 219

Not enough of a mineral or restricted movement in plant.

Front 220

What are the top three limiting nutrients?

Back 220

Phosphate (P), Potassium (K), Nitrogen (N)

Front 221

What does a phosphate-deficient plant look like?

Back 221

Red/purple coloration on edges/margins of leaves.

Front 222

What does a potassium-deficient plant look like?

Back 222

Chlorosis - yellowing on edges/margins of leaves.

Front 223

What does a nitrogen-deficient plant look like?

Back 223

Chlorosis - yellowing in center of leaf between veins.

Front 224

Chlorosis can lead to what?

Back 224

Necrosis (leaf death)

Front 225

Where do you see deficiencies when elements are mobile?

Back 225

In old leaves (elements are drawn to sinks at new leaves)

Front 226

Where do you see deficiencies when elements are immobile?

Back 226

In new leaves

Front 227

What does a Ca (immobile) deficiency in tomatoes produce? Why?

Back 227

Tomato blossom end rot - cell walls are mushy

Front 228

What is the ideal pH for soils?

Back 228

Average around 7, but slightly acidic may be advantageous in some cases (higher H+ conc. can displace positively charged minerals from soil particles making them more available for absorption)

Front 229

Why are heavy quantities of some nutrients detrimental?

Back 229

Toxicity or overdoses can result and harm the plant.

Front 230

What does nitrogen fixation do?

Back 230

N2 --> (NH3 -->) NH4+

Front 231

What does nitrification do?

Back 231

NH4+ --> NO2- + NO3-

Front 232

What does denitrification do?

Back 232

NO3- --> N2

Front 233

What is the preferred compound of nitrogen for the plant?

Back 233

NO3- (can accept NH4+, but not preferred)

Front 234

What do plant enzymes reduce NO3- to in side the plant? Why?

Back 234

NH4+ for synthesis of amino acids / organic compounds

Front 235

What is the N fixing bacteria that has a symbiosis with legume roots?

Back 235

Rhizobia

Front 236

What does rhizobia do for plants? Why does it rely on the plant?

Back 236

Rhizobia fixes nitrogen, but needs nitrogenase from leghemoglobin (which is found in eukaryotes)

Front 237

What are Diazotrophs? Example?

Back 237

Free-living organisms that fix nitrogen into NH3 (cyanobacteria)

Front 238

What form do rhizobium bacteria assume inside the vesicles in the root cell?

Back 238

Bacteroids

Front 239

What are the swelling in the legume roots? What causes these?

Back 239

Nodules - caused by plant cells that have been "infected" by rhizobium

Front 240

Each legume has a specific strand of Rhizobia, how do they recognize their specific strand?

Back 240

Flavonoids - chemical signals

Front 241

Which enzyme breaks the N2 triple bond to make NH4+? How much energy does this take? What is one specific requirement?

Back 241

Nitrogenase
A significant amount (16 ATP)
Can't be exposed to O2

Front 242

What is the protein that regulates O2 concentration so it is not harmful to nitrogenase?

Back 242

Leghemoglobin (produced by eukaryotes, symbiosis)

Front 243

Do Rhizobia + Legumes generate more or less usable nitrogen for plants than industrial fertilizers?

Back 243

More

Front 244

What is "Green Manure"?

Back 244

Growth of crops just to produce nitrogen for the soil, plow it up into soil and then plant your harvesting crop.
Restores concentration of fixed N2 in the soil.

Front 245

Rice has a symbiosis with what? How does this symbiosis work?

Back 245

Azolla (fern with mutualistic cyanobacteria Anabaena, which fixes N2)
Rice kills the Azolla releasing nitrogen-rich organic material for increased fertility)

Front 246

What are the two kinds of mycorrhizae? How are they different?

Back 246

Arbuscular mycorrhizae (endomycorrhizae - penetrates cortex/cells making arbuscules - branched structures)
Ectomycorrhizae (encloses surface around roots)

Front 247

What evolutionary characteristic was helpful in the colonization of land by plants?

Back 247

Mycorrhizae symbiosis

Front 248

What is an epiphyte? What kind of relationship does it form?

Back 248

A plant that lives on the surface of another plant; gets water and nutrients from rain via leaves (not roots)
Forms a commensal relationship

Front 249

What are four kinds of parasitic plants we talked about?

Back 249

Mistletoe
Witchweed
Indian Pipe (ghost flower)
Dodder

Front 250

What are carniverous plants?

Back 250

Venus Flytrap and Sundews - obtain N from insect prey

Front 251

What are the four main parts of an angiosperm?

Back 251

Sepal, Petals, Stamen (m), Carpel (f)

Front 252

Which part of the angiosperm is green and leaflike; it encloses and protects the floral bud?

Back 252

Sepal

Front 253

Which part of the angiosperm is brightly colored to attract pollinators?

Back 253

Petals

Front 254

Which part of the angiosperm contains the male reproductive portion? What two parts make up this structure?

Back 254

Stamen (anther and filament)

Front 255

Which part of the angiosperm contains the female reproductive portion? What three parts make up this structure?

Back 255

Carpel (stigma, style, and ovary)

Front 256

In the ABC theory, what do the genes (A, B, and C) make?

Back 256

A = sepals
A+B = petals
B+C = stamens
C = carpels

Front 257

Which part of the stamen contains the pollen sacs? Connects that part to the base of the flower?

Back 257

Anther
Filament

Front 258

Which part of the carpel is the landing pad for the pollen grain? Transfers the pollen tube? To the ___ containing the ovule?

Back 258

Stigma
Style
Ovary

Front 259

In the ABC theory, what is the rule of thumb?

Back 259

A replaces C, C replaces A.
(ex: Lacking A, extra C (carpels),
Lacking B; just A and C;
Lacking C, extra A (sepals and petals)

Front 260

What is characteristic of a complete flower?

Back 260

It contains all four parts of an angiosperm.

Front 261

What characterizes an angiosperm described as "imperfect"?

Back 261

Only has one sex (stamens or carpels).

Front 262

What are the steps for an angiosperm life cycle? (7 steps)

Back 262

1) microsporangium contains microsporophytes that divide by meiosis to produce microspores (male)
2) microspore becomes pollen grain (male gametophyte) (n)
3) megasporangium produces megaspores (n) to form female gametophyte
4) pollination at stigma, pollen tube forms, two sperm cells enter ovule
5) double fertilization (sperm + egg = zygote (2n); sperm + polar nuclei = endosperm (3n)
6) zygote forms seed / fruit
7) seed germinates develops into mature sporophyte (2n)

Front 263

The male gametophyte is made up of two cells...?

Back 263

Pollen tube cell which contains generative cell

Front 264

What does the generative cell do in the pollen grain?

Back 264

Produces 2 sperm for double fertilization.

Front 265

In the female gametophyte, there are how many nuclei? What are the names of all of them?

Back 265

8 haploid nuclei:
- 3 antipodal cells
- 2 polar nuclei
- 2 synergids
- 1 egg

Front 266

What is the function of the synergids?

Back 266

They guide / attract the pollen tube to the egg.

Front 267

What is pollination?

Back 267

The transfer of pollen from anther to stigma for double fertilization.

Front 268

In what ways can pollination occur?

Back 268

- Abiotically by wind
- Pollination by bees
- By moths / butterflies
- By flies
- By birds
- By bats

Front 269

What is meant by the "self-breeding depression"?

Back 269

When flowers/plants are complete and self-fertilize leading to low genetic variation.

Front 270

What is meant by an "incomplete" flower?

Back 270

Missing any one part of the four angiosperm parts.

Front 271

What is a "monoecious" plant?

Back 271

Self-fertilized.

Front 272

What is a "monoecious" plant?

Back 272

Self-fertilized.

Front 273

What is a "diecious" plant?

Back 273

Only has male or female parts, not both; prevents self-fertilization.

Front 274

What is a "diecious" plant?

Back 274

Only has male or female parts, not both; prevents self-fertilization.

Front 275

What is a Thrum flower? What is its function?

Back 275

Short styles (carpels) and long stamens; makes it unlikely that a pollinator will get pollen to the stigma of the carpel.

Front 276

What is a Thrum flower? What is its function?

Back 276

Short styles (carpels) and long stamens; makes it unlikely that a pollinator will get pollen to the stigma of the carpel.

Front 277

What is a Pin flower? What is its function?

Back 277

Short stamens and long styles (carpels); makes it unlikely that a pollinator will obtain the pollen from the stamen.

Front 278

What is a Pin flower? What is its function?

Back 278

Short stamens and long styles (carpels); makes it unlikely that a pollinator will obtain the pollen from the stamen.

Front 279

What are S genes?

Back 279

Genes that recognize the self (or close relatives) and prevents self-fertilization.

Front 280

What are S genes?

Back 280

Genes that recognize the self (or close relatives) and prevents self-fertilization.

Front 281

In double fertilization, where do the two sperm go to? To produce what?

Back 281

Sperm + Egg = Zygote (2n)
Sperm + 2 Polar Nuclei = Endosperm (3n)

Front 282

In double fertilization, where do the two sperm go to? To produce what?

Back 282

Sperm + Egg = Zygote (2n)
Sperm + 2 Polar Nuclei = Endosperm (3n)

Front 283

What does the ovule become?
The ovary?

Back 283

Ovule => Seed
Ovary => Fruit

Front 284

What does the ovule become?
The ovary?

Back 284

Ovule => Seed
Ovary => Fruit

Front 285

What are the steps leading from the zygote to the seed?

Back 285

Cell division - unequal sized cells allows polarity determination;
Leads to embryo containing root apex and shoot apex;
Cotyledons stick out off of shoot apex end;
Integuments form hard seed coat.

Front 286

What are the steps leading from the zygote to the seed?

Back 286

Cell division - unequal sized cells allows polarity determination;
Leads to embryo containing root apex and shoot apex;
Cotyledons stick out off of shoot apex end;
Integuments form hard seed coat.

Front 287

What are the four kinds of flowers/fruits? What distinguishes them from one another? (example)

Back 287

1) Simple fruit - single or several fused carpels (pea)
2) Aggregate fruit - >1 separate carpels each forming small fruit (raspberry)
3) Multiple fruit - multiple flowers tightly clustered that fuse together (pineapple)
4) Accessory fruit - "fruit" forms from another part of plant, like enlarged receptacle, low in stem (apples)

Front 288

What are the four kinds of flowers/fruits? What distinguishes them from one another? (example)

Back 288

1) Simple fruit - single or several fused carpels (pea)
2) Aggregate fruit - >1 separate carpels each forming small fruit (raspberry)
3) Multiple fruit - multiple flowers tightly clustered that fuse together (pineapple)
4) Accessory fruit - "fruit" forms from another part of plant, like enlarged receptacle, low in stem (apples)

Front 289

What are the three generations seeds contain?

Back 289

- Mother sporophyte
- Gametophyte
- M/F new sporophyte

Front 290

What are the three generations seeds contain?

Back 290

- Mother sporophyte
- Gametophyte
- M/F new sporophyte

Front 291

In what ways can seeds be dispersed?

Back 291

Water, wind, animals.

Front 292

In eudicots with thick cotyledons, what structures are present?

Back 292

Seed coat, radicle, hypocotyl, two cotyledons.

Front 293

In eudicots with thin cotyledons, what structures are present?

Back 293

Seed coat, endosperm, cotyledons, hypocotyl, radicle.

Front 294

What structures distinguish monocot seeds from eudicot seeds?

Back 294

Coleoptile, coleorhiza, and pericarp.

Front 295

What is the structure that covers the young shoot in monocot seeds? Covers the young root?

Back 295

Coleoptile (shoot)
Coleorhiza (root)

Front 296

What is the pericarp? What happens to it in monocot seeds?

Back 296

Pericarp is the fruit / mature ovary tissue; it is fused to the seed coat in monocots.

Front 297

What is the structure that stores nutrients that can be used by seedling after germination?

Back 297

Endosperm

Front 298

What are the structure(s) that absorb nutrients from endosperm and transfer to the rest of the embryo when seed germinates?

Back 298

Cotyledons

Front 299

What is the most commonly utilized herbicide (most kg applied)?

Back 299

Herbicides

Front 300

If a species is adapted to low resource availability, is it likely to have a smaller or larger seed?

Back 300

Larger seed (more nutrients stored...)

Front 301

When a seed stops growing and the metabolism nearly ceases, it is said to be?

Back 301

Dormant

Front 302

In what five ways can seed dormancy usually be broken / get seed to germinate?

Back 302

1) Pre-chilling (common in middle latitudes due to winter --> spring)
2) Smoke can stimulate in fire-adapted species
3) Seed coat weakened by chemical attack (animal digestive tract)
4) Light stimulation (buried shallow enough)
5) Substantial rainfall

Front 303

What is the first organ to emerge from a germinating seed? What does it form?

Back 303

Radicle - forms root system

Front 304

What occurs after the radicle/root system emerges?

Back 304

Hook forms in hypocotyl; growth pushes the hook above ground.

Front 305

When the (eudicot) hypocotyl hook pushes up out of the ground during germination, the cotyledons can be above ground or under ground, what are these called?

Back 305

Cotyledons above soil = epigeal germination
Cotyledons below soil = hypogeal germination

Front 306

Monocots' radicle emerges first during germination, followed by what?

Back 306

Coleoptile pushes upward through soil and into the air (shoot system)

Front 307

What is asexual reproduction?

Back 307

Vegetative reproduction in plants; offspring from single parent; no genetic recombination; forms clones.

Front 308

When fruits and seeds are produced int he absence of fertilization / pollination, it is called?

Back 308

Apomixis

Front 309

What is the main historical example of artificial selection in "plant breeding"?

Back 309

Maize / Corn

Front 310

What does it mean to be "transgenic"?

Back 310

Genetically modified to express gene(s) from another species.

Front 311

What is a plant cell that has had its cell wall removed (by cellulase and pectinase)? Why is this done?

Back 311

Protoplast; for plant breeding.

Front 312

How do scientists add plasmids to protoplasts (cells with a removed cell wall)?

Back 312

Shoot protoplasts with gold beads with DNA on them; DNA from bacteria/gene is incorporated into DNA of plant.

Front 313

What are the three steps in signal transduction?

Back 313

1) Reception (detects signal from environment
2) Transduction (communication)
3) Response by plant

Front 314

Where are the receptors for plants often located?

Back 314

Trans-membrane molecules

Front 315

What mechanism explains xylem movement? Phloem movement?

Back 315

Transpiration = xylem
Pressure-Flow hypothesis = phloem

Front 316

Hormones usually have what concentration in plants?

Back 316

Low

Front 317

What is the response of plants called when they bend towards light?

Back 317

Phototropism

Front 318

What is the primary function of Auxin (IAA)?

Back 318

Cell elongation; enhances apical dominance; produced in apex, transported downward for root growth.

Front 319

What is the primary function of Cytokinin?

Back 319

Cell division; involved in apical dominance; produced in roots, transported up to shoots.

Front 320

Which hormone is involved in stem elongation and growth and stimulates germination of seeds?

Back 320

Gibberelins

Front 321

Which hormone is a repressor of plant growth and is in the roots (when there is a drought it moves to leaves and tells guard cells to pump out K+ to close stomates).

Back 321

ABA (Abscisic Acid)

Front 322

Which of the plant hormones is a gas? It is involved in apoptosis and senescence (programmed cell death).

Back 322

Ethylene

Front 323

What is the onset of programmed cell death called?

Back 323

Apoptosis

Front 324

What is programmed cell death also known as?

Back 324

Senescence

Front 325

Which hormone is a signal in the fall for plant leaves to fall; fruits to ripen?

Back 325

Ethylene

Front 326

What is the triple response?

Back 326

A response to an obstacle: plant stem bends, thickens and continues to grow horizontally.

Front 327

What are phytochromes sensitive to?

Back 327

Red light

Front 328

How do you go from Pr --> Pfr? Reverse?

Back 328

Hit with red light.
Hit with far-red light.

Front 329

Pr --> Pfr --> ???

Back 329

Seed germination, control of flowering, etc.

Front 330

Which kind of plants will flower when there is a long night interrupted by a red light?

Back 330

Long day, short night plants.

Front 331

Which kind of plants will flower when there is a long night interrupted by a red light followed by a far-red light?

Back 331

Short day, long night plants.

Front 332

Which kind of plants assimilate CO2 better at low concentrations? At high concentrations?

Back 332

Low = C4
High = C3