Topics 06-08 Terms (Plant Chunk)

Question 1

endodermal barrier

Answer 1

In roots, casparian strips block flow to the inside where xylem is located

Water/ions must enter endodermal cells to get to xylem

Question 2

_____% of water taken up from roots lost to _______, mainly in the form of ____

Answer 2

90% of water is lost to evaporation, usually as water vapor

Question 3

How turgor is maintained

Answer 3

Potassium ion uptake with ATP-powered ion channels

Water enters due to osmotic imbalance

Guard cells control stomata which control turgor

Question 4

aerenchyma

Answer 4

loose parenchyma with
air spaces

allow oxygen transport to below-water parts

found in water lilies and others

Question 5

flooding cons

Answer 5

depletes oxygen in roots

loss of active pumping at root hairs

loss of ion entry

may dry out leaves

Question 6

lenticels

Answer 6

above water; allow oxygen to enter

Question 7

pneumatophores

Answer 7

spongy, air-filled “knees”
from roots, emerging from
water

Question 8

Food transport in phloem is mostly ___% dry matter and almost consisting entirely of _____

Answer 8

10-25% dry matter, mostly sucrose

Question 9

How food transport happens

Answer 9

pressure flow hypothesis

source (place of dissolved carb production)

sink (place of usage
(primarily growing areas –
root and stem tips, fruits)
or storage)

Question 10

Phloem loading

Answer 10

Carbs enter sieve tubes at source (active transport)

Companion cells provide energy

Water potential in sieve tube lowered, relative to nearby xylem

Increased turgor pressure in sieve tube pushes solution through them

Question 11

“unloading” at a sink

Answer 11

Carbs leaving drop turgor pressure

Makes the flow from high water pressure at source to low pressure at sink

Most water in sink diffuse back into xylem

Question 12

Macronutrients in plants

Answer 12

(7) COHNK CaMg (conk, camgie)

Question 13

Micronutrients in plants

Answer 13

(8) Cl Fe Mn B Zn Cu Ni Mo (“cliffy men, beezin’ sunny mo!”)

Question 14

How nitrogen is fixed for plants

Answer 14

Nitrogen-fixing bacteria turn N2 into NH3 (ammonia).

Ammonifying bacteria turn NH3 into NH4+.
Nitrifying bacteria turn NH4+ into NO3-.

Plants can only use nitrogen in the form of NH4+ or NO3-

Denitrifying bacteria take ions and turn it back into atmospheric N2

Question 15

Commercial fertilizers usually include _, _, and _.

Answer 15

N P K

Question 16

Disadvantages of commercial fertilizers

Answer 16

can be expensive

can pollute water supplies and
damage ecosystems

Question 17

Organic fertilizer makes ______

Answer 17

Humus; helps hold

water and is usually less polluting of surface waters

Question 18

Environments of carnivorous plants

Answer 18

sandy, acidic soils (like bogs) often have too

little nitrogen

Question 19

Venus fly trap

Answer 19

brushed hair causes
electrical impulse, which causes very rapid water accumulation in the outer regions of lobes

digestive enzymes

usually eat more ants/grasshopper than flies

Question 20

sundews

Answer 20

Trichomes act as glands, secreting sticky substances including digestive enzymes

Leaves curl around prey

Question 21

butterworts

Answer 21

Glands on leaves secrete sticky
substances and
digestive enzymes

Leaves curl around prey, mostly gnats

Question 22

pitcher plants

Answer 22

Insects can’t climb back out

Some have digestive enzymes, some digest using other organisms through mutualism

Question 23

Bladderworts

Answer 23

traps in aqueous environments

bladderlike leaves that have a spring-like trapdoor

digestive enzymes

Question 24

mycorrhizae

Answer 24

90% of vascular plants have relationships between their roots and these certain fungi

important mostly for phosphorous and micronutrients

Question 25

Plant development characteristics

Answer 25

Cells do not change positions during development Growing tips and zones (meristems); regeneration capacity No fixed body size, flexibility and adaptability Adaptive development influenced by environment

Question 26

Fungi and animal development

Answer 26

Fungi grow with little specialization, except for reproduction Animal development is usually complex but relatively inflexible

Question 27

suspensor

Answer 27

larger cell in the first division of a seed embryo links embryo to nutrient tissue in seed

Question 28

root-shoot axis

Answer 28

Near suspensor = future root Other end = future shoot

Question 29

mature seed embryo characteristics

Answer 29

Root-shoot axis Cotyledons growing out of shoot Plumule; may have a coleoptile (protective sheath)

Question 30

Where food is stored in a seed

Answer 30

Endosperm or cotyledons

Question 31

____% of seeds are water

Answer 31

5-20% water

Question 32

Food reserves in seeds are mostly ________

Answer 32

starch grains in amyloplasts, protein bodies, sometimes fat bodies

Question 33

First step in seedling growth

Answer 33

roots emerge first (usually)

Question 34

Plant hormones control _______

Answer 34

gene expression

Question 35

Auxin

Answer 35

Elongates cells, and is transported away from areas in the light Usually found in apical meristems or other immature areas plasticity of cell walls bending of stems, stem elongation inhibits leaf abscission promotes lateral bud dormancy

Question 36

Cytokinins

Answer 36

Natural ones similar to adenine Usually produced in root apical meristems and developing fruits cell differentiation works with auxin to stimulate cell division promote lateral buds, inhibit lateral root growth promote chloroplast development/maintenance

Question 37

Gibberellins

Answer 37

Activate production of food utilization enzymes Made in apical parts of stems and roots shoot elongation, hastened seed germination

Question 38

Brassinosteroids

Answer 38

Overlapping functions with auxins and gibberellins Found in pollen, immature seeds, shoots, and leaves

Question 39

Oligosaccharins

Answer 39

Pathogen defense (possible reproductive development) Found in cell walls

Question 40

Ethylene

Answer 40

Promote some defense responses to environmental stress Formed around lateral buds stimulated by auxin, in pollinated flowers, developing fruits lows stem and root growth hastens fruit ripening increase in respiration in fruits allows abscission at fruit peduncles and leaf petioles

Question 41

Abscisic acid

Answer 41

Seed dormancy Affects stomata opening and closing Made in mature green leaves, fruits, root caps produces a yellow area when applied to a green area very rapid effects; not likely to be due to changes in gene expression

Question 42

salicyclic acid

Answer 42

Plant defense responses against pathogens

Question 43

apical dominance depends on combined effects of ____, _____, ______

Answer 43

auxin, cytokinins, ethylene

Question 44

final plant form typically determined by a balance of ______ and ______

Answer 44

auxin and cytokinins

Question 45

tropism

Answer 45

growth responses to external stimuli (irreversible growth)

Question 46

phototropism

Answer 46

Stem systems grow toward light (auxin often involved)

Question 47

gravitropism

Answer 47

Stems grow up, roots grow down

Question 48

thigmotropism

Answer 48

Response to contact; examples are tendrils, venus flytrap closing

Question 49

turgor movements

Answer 49

Reversible changes in turgor pressure Involves active ion import/export, water influx/efflux to relieve osmotic imbalance Examples are opening/closing stomata, "opening/closing" leaves and flowers

Question 50

photoperiodism

Answer 50

response to a length of DARK period

Question 51

long-day plants

Answer 51

Flower only when the day length is over 12-16 hours

Question 52

short-day plants

Answer 52

AKA "long night" plants Flower only when day length is shorter than 14 hours

Question 53

Color light most effective in stopping flowering

Answer 53

Red light

Question 54

phytochrome

Answer 54

A blue pigment with two states (Pr and Pfr) involved in flowering Affects etiolation Pfr is biologically active, Pr is not Pfr becomes Pr over time in the dark