Plant Biology

Front 1

What are five common features of plants?

Back 1

1.) Photosynthesis
2.) Sessile
3.) Internal Structural support system
4.) evolved mechanisms for acquiring water and nutrients
5.) evolved mechanisms to avoid dessication

Front 2

What are some common characteristics of plants?

Back 2

1.) Modular construction-> made up of repetitive units
2.) No nervous system
3.) Cellulose wall-> plants can't migrate
4.) Vacuole-> 95% predominant
5.)Sex cells arise late in development-> no germ line

Front 3

Where does new growth primarily occur in plants?

Back 3

At meristems

Front 4

What are meristems?

Back 4

groups of undifferentiated cells that give rise to post-embryonic organs and tissues of plants

Front 5

What gives rise to primary growth (makes plants taller)?

Back 5

apical meristems

Front 6

What is secondary growth?

Back 6

It helps plants get wider-> increases the diameter of roots and stems that have stopped elongating; predominant in woody plants

Front 7

What is a protoplast?

Back 7

Plant cell minus the cell wall

Front 8

What is the outer part of the cell wall that is sticky?

Back 8

pectin

Front 9

What do secondary cell walls contain that makes them so hard?

Back 9

lignin

Front 10

What is the outer tissue system?

Back 10

dermal

Front 11

What is the transport system of the plant?

Back 11

the vascular system

Front 12

What is responsible for water transport?

Back 12

xylem

Front 13

What is responsible for distributing products of photosynthesis throughout plant?

Back 13

ploem

Front 14

What are the most common cells of ground tissue that have very thin walls?

Back 14

parenchyma

Front 15

What cells of ground tissue support parts of plants that are no longer growing, contain secondary cell walls, and can be arranged either into sclerids or long fibers?

Back 15

sclerenchyma

Front 16

What are the cells of ground tissue that have thick primary cell walls that support parts of plant that is still growing?

Back 16

collenchyma

Front 17

what is the most abundant polysaccharide in the cell wall?

Back 17

cellulose

Front 18

What membrane is the vacuole bound by?

Back 18

the tonoplast

Front 19

What are the functions of the vacuole?

Back 19

-growing of plant cell/cell elongation
-storage-> toxins or pigments
-breakdown of macromolecules-> lytic vacuole-> if plant wants to get rid of protein

Front 20

What are self-replicating organelles that are maternally inherited, have their own genome, and surrounded by a double membrane?

Back 20

plastids

Front 21

What is the site of photosynthesis that contains chlorophyll and other carotenoids, which are embedded in the thylakoid membrane?

Back 21

chloroplast

Front 22

What is the liquid that the thylakoid sits in?

Back 22

stroma

Front 23

What type of plastids synthesize and accumulate carotenoids-> gives colors to petals and certain flowers?

Back 23

chromoplasts

Front 24

What type of plastid has no pigments? Amyloplast is a type-> stores starch.

Back 24

leucoplasts

Front 25

What type of plastids are meristematic cells that are the the precursors of other plastids?

Back 25

proplastids

Front 26

What is the plant cytoskeleton made up of?

Back 26

actin filaments and microtules

Front 27

Microtubules

Back 27

-made of tubulin subunits
-dimer formed from one alpha and one beta subunit-> long protofilament
-diameter of 25 nm

Front 28

Actin

Back 28

-G-actin subunits-> F-actin (protofilament)-> 2 wrap around each other-> actin filament
-filaments are dynamic

Front 29

preprophase band

Back 29

-specialized cytoskeletal array
-determines plane of cell division
-a band of microtubules that encircles the nucleus in the periphery of the cell

Front 30

phragmoplast

Back 30

-helps to construct cell plate (precursor of cell wall)-> separates 2 daughter cells after cell division

Front 31

What regulates activity of the cell cycle?

Back 31

CDK's

Front 32

How does cytokinin promote cell division?

Back 32

by upregulating the expression of cyclin D3

Front 33

What are openings in cell wall?

Back 33

plasmodesmata

Front 34

What is the rod of ER that runs through the center of the plasmodesmata?

Back 34

desmotubule

Front 35

When is primary plasmodesmata created?

Back 35

during cytokinesis

Front 36

What does transcriptional regulation involve?

Back 36

primarily controlled at transcription intitiation, can also be controlled at maintenance and termination

Front 37

Post-transcriptional regulation

Back 37

controls on mRNA stability
translation efficiency
degradation

Front 38

Post-translational regulation

Back 38

-regulation of protein activity
-protein stability

Front 39

How is the transcription intitiation complex formed?

Back 39

TBP binds to the TATA box-> these general transcription factors bind with RNA polymerase to form transcription initiation complex

Front 40

Which type of chromatin is highly compact and transcriptionally inactive?

Back 40

heterochromatin

Front 41

Which type of chromatin is transcriptionally active and dispersed?

Back 41

euchromatin

Front 42

What does the degree of DNA packing depend on ?

Back 42

covalent modifications that occur on both DNA and histone proteins

Front 43

How does DNA modification occur?

Back 43

by methalyation of cytosine residues

Front 44

How does histone modification occur?

Back 44

1.) methylation of lysine residues (dimethylation of H3K4-> active genes; dimethylation of H3K9-> inactive genes
2.) acetylation-> performed by HATs

Front 45

What is an example of posttranscriptional regulation?

Back 45

after transcription, resulting mRNA's processed-> spliced, addition of 5' cap and 3' poly A tail, export from nucleus

Front 46

How can dsRNA be produced in plant cells?

Back 46

-presence of miRNAs
-production of siRNAs
-foreign RNAs

Front 47

What enzyme processes the pri-miRNA into mature miRNA

Back 47

DCL1 and HYL1

Front 48

What does posttranslational regulation do?

Back 48

determine life span of proteins

Front 49

What are the two pathways for protein turnover?

Back 49

1.) lytic vacuole-> acidic environment with degrading enzymes
2.) ubiquitin pathway-> 26S proteasome

Front 50

Where does CO2 enter leaf

Back 50

stomata

Front 51

What is transpiration?

Back 51

plants maintain balance of uptake of water by roots and loss of water at leaf surface

Front 52

What are strong intermolecular interactions among water molecules?

Back 52

cohesion

Front 53

what is the attraction of water to a solid surface (walls of plant cell)?

Back 53

adhesion

Front 54

what are aquaporins?

Back 54

integral membrane proteins that help water cross lipid bilayer that affect rate at which water crosses
-reversible, gated openings

Front 55

what hormone regulates stomata opening/closing?

Back 55

ABA

Front 56

what is the movement of water in response to pressure gradient?

Back 56

bulk flow

Front 57

what are thin outgrowths on the root epidermal cell that greatly enahance surface area of the toot/

Back 57

root hairs

Front 58

What type of pathway is it when water moves through the cell walls and extracellular spaces and water doesn't cross the plasma membrane

Back 58

apoplast

Front 59

What type of pathway where water moves through cells connected by plasmodesmata and water doesn't cross the plasma membrane?

Back 59

symplast

Front 60

What type of pathway where water enters cell on one side and exits on other side; it does cross p.m

Back 60

transmembrane

Front 61

what is the waxy band found within radial of cell wall of all endodermal cells that blocks movement of water?

Back 61

casparian strip

Front 62

What is root pressure?

Back 62

osmotic pressure within cell of root system that causes xylem sap to move up plant stem

Front 63

What is transpiration?

Back 63

loss of water vapor from leaves that pulls water up the plant-> generates a negative hydrostatic pressure

Front 64

What are two types of tracheary elements *conducting cells*?

Back 64

tracheids and vessel elements

Front 65

What are elongated spindle-shaped cells that are associated, over-lapping vertical files?

Back 65

tracheids

Front 66

how does water flow through tracheids?

Back 66

through pit pairs

Front 67

What are the shorter, wider cells that can associate end to end to form vessels?

Back 67

vessel elements

Front 68

what does rate of flow depend on?

Back 68

-radius of tube
-viscosity of solution
-pressure gradient-> the bigger, the faster

Front 69

what in xylem drives long-distance transport?

Back 69

tension

Front 70

what is the breakage of water column by air bubbles?

Back 70

cavitation

Front 71

how do plants minimize the impact of xylem cavitation?

Back 71

pit membrane acts as filter to prevent air bubbles from entering xylem in 1st place

Front 72

what is the opening/closing of the stomata controlled by?

Back 72

guard cells

Front 73

How does short-distance transport occur?

Back 73

by osmosis-> driven by gradients in water potential-> differences in both solute concentration and pressure contribute to this

Front 74

what are essential elements?

Back 74

elements required for plant life-> can make up actual structures/ components needed for plant metabolism; their absence results in severe abnormalities in plant growth, development, and reproduction

Front 75

What is a hydrophonic growth system?

Back 75

plants grown with their roots immersed in nutrient solution without soil

Front 76

what are elements such as N, P, K tha plants acquire from soil in the form of inorganic ions

Back 76

Mineral nutrient

Front 77

Macronutrients

Back 77

N,K,Ca,Mg,P,S,Si .1-1.5% drymass

Front 78

micronutrients

Back 78

Cl, Fe, B, Mn, Zn, Na, Cu, Ni, Mo .1-100 ppm

Front 79

What mineral element do plants require most

Back 79

Nitrogen

Front 80

What is the nutritional disorder that causes yellowing of the leaf, leaves may fall of, and anthocyanin may build up?

Back 80

chlorosis

Front 81

what nutritional disorder typically occurs on younger leaves and is referred to chlorosis between leaves?

Back 81

intravenous chlorosis

Front 82

what tells you the level of nutrients potentially available to the plant?

Back 82

soil analysis

Front 83

what is the term for when there is no further increase in growth in response to an increase in nutrient solution

Back 83

critical concentration

Front 84

what does root growth depend on

Back 84

availability of water and minerals in the rhizosphere

Front 85

what type of root system has primary root/taproot with lateral roots branching out and found in most dicots and tends to grow deeper within soil systems

Back 85

taproot system

Front 86

what type of root system has 3-6 primary roots developing from the germinating seed and found in monocots

Back 86

fibrous root system

Front 87

what is found at the very tip of the root and protects meristematic cells of root apical meristem

Back 87

root cap

Front 88

what does the root cap excrete

Back 88

mucigel-> lubrication

Front 89

what is the region in which cells are dividing, contributing to root growth; includes root apical meristem and surrounding cells

Back 89

meristematic zone

Front 90

region in which cells are elongating in length

Back 90

elongation zone

Front 91

region in which root hairs are present and cells begin to differentiate

Back 91

maturation zone

Front 92

what facilitates nutrient uptake by roots

Back 92

mycorrhizal fungi

Front 93

what type of fungi creates a network of hyphae around cortical cells called hartig net

Back 93

ectotrophic mycorrhizae

Front 94

what type of fungi has hyphae that extends between cells and penetrates individual cells of the cortex

Back 94

arbuscular mycorrhizae