lesson 2

Question 1

define macronutrients

Answer 1

abundance of these within plants, used for structure+ major molecules

Question 2

define micronutrients

Answer 2

required in small amounts as cofactors for enzymes

Question 3

define metallothioniens + phytocholatins

Answer 3

bind and neutralize toxic substances including heavy metals.

Question 4

define tonoplasts

Answer 4

central vacoule membrane that limits movement of nonessential + potentially toxic materials from entering the vascular cylinder

Question 5

tonoplasts, metallothoniens and phylocholatins require what??

Answer 5

energy

Question 6

define phytomenediation

Answer 6

certain plants being planted in toxic soil so that they absorb the toxic materials and then are removed and incinerated

Question 7

define hydroponics

Answer 7

technique used to determine which elements are required for most vascular plants

Question 8

define rhizobium

Answer 8

genus of Nfixing bacteria that can live in root cells of plants in pea family.

Question 9

how do rhizobium infect plant root

Answer 9

1. roots emit flavanoids that binds to receptors of rhizobia soil
2. rhizobia secrete nod factors to bind to root hair cells
3. causes entry of Ca2+ into root hair cells causing to swell + curl around rhizobia
4. rhizo inject infection protiens to induce root to develop infection thread so rhizo penetrates into root cortex cells
5. protien called nodulins cause root cortex to divide forming nodules. rhizo make more nodules. rhizo then divide and transform into bacteriods
6. nodules become pink inside as O2 regulating lehemoglobin is produced
7. nodules develop vasc tiss to transport N to shoot up and organic C down to bacteroids

Question 10

carnivorous plants nutritional adaptation

Answer 10

tend to live in places lacking N. photosynthetic and catch animals for N.

Question 11

parasitic plants nutritional adaptation

Answer 11

absorb sugars + minerals from host. some photosynthetic. mistletoe can kill trees. dodder yellow and smother host plant + penetrate into xylem tissue. ghost plants nonphoto tap into roots of plant via fungi + steal nutrients.

Question 12

epiphytes nutritional adaptation

Answer 12

not parasitic but live attached to other plants and obtain nutrients via dust

Question 13

how do flowers develop?

Answer 13

from modified apical meristems=flower buds

Question 14

define florigen

Answer 14

involved in conversion of apical buds into flower bud

Question 15

define calyx

Answer 15

collection of sepals which protect flower bud before opening

Question 16

define corolla

Answer 16

collection of petals(showy + colorfull) contain nectaries or scents to attract pollenators.

Question 17

define stamen

Answer 17

formed of filament + anther(contains microsporangia) fila determines placement of anther

Question 18

define microspore mother cell

Answer 18

in microsporangia + undergo meiosis to form microspores (1n)

Question 19

describe double fertilization

Answer 19

each 2N microspore mother cell of anther produces 4 microspores via miotic division each 1n microspore will produce a multicellular male gametophyte aka pollen grain one mitotic division. Pollen grain consists of two cells generative cell and tube cell. Tube cell lands on stigma if right molecules interact tube cell will develop pollen tube to ovule while happening generative cell divides into two non flagellated sperm cells to get to female gametophyte AKA embryo SAC which has 8 nucleic seven cells. Antipodal use for early nutrition and will degenerate, synergids help pollen tube reach egg, sperm enter ovule through microphyle and one sperm fertilizes egg making 2N zygote second sperm fertilizes 2 polar bodies making 3N endosperm. Endosperm food reserved for embryo replaced and some dicots by cotyledons which nourish developing sprout after fertilization ovule develops into seed and ovary develops into fruit endosperm often fluid and can be replaced by solid endosperm.

Question 20

where does triploid cell(endosperm) come from in double fert?

Answer 20

from sperm fertilizing the polar body

Question 21

define scarification

Answer 21

any manipulation to seed coat to allow water entrance into the seed. (ex scratches, digestive enzymes)

Question 22

define pollination

Answer 22

pollen grain going from the anther to the stigma

Question 23

two types of pollination? describe them

Answer 23

wind- inconspicuous flowers release pollen into air
animal- conspicuous flowers use scents and food reward to attract vertebrae and invertebrate

Question 24

what do bees/insects see in?

Answer 24

ultraviolet so more attracted to flowers

Question 25

define apomixis

Answer 25

asexual reproduction of seeds + dispersal of them

Question 26

Each ___ microspore mother cell of the anther will produce ____ microspores by _____ divisions.

Answer 26

diploid, four, meiotic

Question 27

Each ____ microspore will produce a multicellular male gametophyte (pollen grain) by undergoing one ____ division.

Answer 27

haploid, mitotic

Question 28

define nectar

Answer 28

sugary solution from nectaries or floral glands: energy rich food. reward for pollinator

Question 29

pollen grains

Answer 29

protein rich food for many animals (BTW saffron currently favored by humans, is this)

Question 30

describe flower coloration and colors associated with animals. and smell

Answer 30

blue and yellow are often associated with insects—but also with ultraviolet wavelengths invisible to humans. Many flowers with distinct markings not seen by human eye that guide pollinator to nectar and pollen grains (Bees purple) Bird-pollinated flowers are red, orange or yellow—birds see these wavelengths. hardly any smell. Bats: typically feed at night on flowers with dull white petals and a strong scent, often of decaying fruit

Question 31

examples of coevolution of pollinators with flowers.

Answer 31

Fuzzy bodies of bumblebees catch and hold pollen; long curved beaks of Honey Creepers in Hawaii: tubular flowers, Orchids: petals mimic female wasps; males attempt to mount = flowing must coincide with mating season.

Question 32

describe how adventiteous plants asexaully reproduce

Answer 32

Plants that have meristematic tissue in notches of leaves that give rise to plantlets.

Question 33

In _____, a Diploid egg can form without fertilization OR cells in ovule develop into an embryo

Answer 33

apoximis

Question 34

define signal transduction pathways(regarding phosphorylation cascades or second messengers) shorthand and how.

Answer 34

shorthand: means by which environmental energy can impinge upon a cell and get it to change its course. how: Either series of chemical reactions begins with a receptor protein in or near a cell membrane. The receptor protein detects a stimulus (energy), such as light, touch, or hormone, and undergoes a conformational change that ultimately results in activation or suppression of translation or transcription, changing the chemical make-up of a cell

Question 35

define tropism

Answer 35

directional growth

Question 36

define phototropism and how

Answer 36

directional growth in plants from response to light. When the receptor molecule phototropin is stimulated by blue light, it will undergo a change in shape that will ultimately result in the synthesis of auxins in cells of the apical meristem. Auxin (IAA) is moved to the shaded side of the stem, where it softens cell walls and allows them to lengthen (hydrogen ions are moved, drawing in water). Because the cells of the shaded side of the developing stem are longer than those on the lit side, the stem "bends" toward the light source.

Question 37

what is positive tropism and negative tropism

Answer 37

positive: towards stimulus negative: away from stimulus

Question 38

define phototropin

Answer 38

receptors sensitive to blue light

Question 39

define auxin(IAA)

Answer 39

a family of hormones in cells of the apical meristem. involved in Phototropism, gravitropism, apical dominance, abscission inhibition (maintains leaves and fruits) work synergistically with other hormones

Question 40

define phytochrome

Answer 40

protien receptor that is used to detect far-red light and red light as its sensitive to it. acts as a switch

Question 41

how does phytochrome work? and whats the word for the process?

Answer 41

Phytochrome undergoes conformational (shape) change, going reversibly from the inactive form Pr to the active form Pfr when stimulated by red light. Plants in shade are exposed to far-red light. When phytochrome is exposed to far-red light, it is converted to the inactive form Pr. This inactive form of the molecules results in the cells of stem tips elongating, and they do not produce chloroplasts, which are energetically costly to produce. As a consequence, shaded stems are spindly, pale, and they grow rapidly. Plant stems that respond in this manner are etiolated. (etiolation)

Question 42

describe how plants determine whether theyre long day plants(bloom short mights-summer), short day plants(blooms long nights- spring and fall), day neutral(no association)

Answer 42

because the Pfr active form will gradually convert to the Pr inactive form in time. This allows for different compounds to accumulate in the cytoplasm during the night--the amount of these chemicals is used by the plant to determine how long the night was.

Question 43

define gravitropism

Answer 43

directional growth to gravity exhibited by roots

Question 44

define thigmotropism

Answer 44

movement associated with touch or mechanical stimulation (mechanical energy used to affect plant growth). on high touch areas plants will be shorter and cells will have thicker walls to make them sturdier

Question 45

describe thigmonastic movements(venus)

Answer 45

in venus fly traps six hairlike triggers, two of which must be touched within 20-30 seconds for trap closure to occur. When triggered, Ca ions are released and send an electrochemical impulse through plasmodesmata along trap cells to the midrib, where specialized protein gates (aquaporins) are open and allow water to flood into midrib cells, increasing turgor pressor and rapidly (a tenth of a second or so) closing

Question 46

define cytokinins (hormone)

Answer 46

regulation of cell cycles = cell divisions and cell elongation in association with Auxins and Gibberellins. They are produced in many tissues.

Question 47

define Gibberellins (GA) hormone

Answer 47

produced in immature seeds and apical meristems, are associated with cell division and elongation and Dwarfing (when not produced). GA instructs plant internodes to lengthen(grapes). affects germination of certain seeds. Gibberellins will stimulate/interact with receptors on membrane of aleurone cells, sending a second messenger to nucleus of those cells and activating genes responsible for producing alpha amylase, an enzyme that converts starch to simple sugars used by the developing embryo.

Question 48

define Aleurone layer

Answer 48

outer layer of the endosperm

Question 49

define Abscisic Acid (ABA) hormone

Answer 49

stress hormone (water), closing stomata to decrease transpiration when plant is under lack of water. It also induces senescence of leaves and fruits, and it inhibits bud growth and seed germination. (high levels of ABA in seeds-washed away by rains, allows germination)

Question 50

define Ethylene hormone

Answer 50

gas produced by all plant organs when stressed. This hormone is involved with fruit ripening and abscission = senescence (drop of fruit). It will Inhibit cell elongation, and promote promotes germination of seeds. As a fruit ages, it produces ethylene in increasing quantities, ripening nearby fruits.

Question 51

define Brassinosteroids hormone

Answer 51

promote growth through elongation of cells in stems and leaves. Brassinosteroids function synergistically with auxins, cytokinins, gibberellins.

Question 52

why plants use pheromone

Answer 52

plants can use pheromones to communicate with other individuals of their species or with other species

Question 53

define systemin

Answer 53

hormone used by plants in response to attack by herbivores, such as caterpillars. Systemin is produced and released by cells damaged by the herbivore (either the mechanical damage or proteins in saliva of the herbivore stimulate the process = mechanical or chemical energy). Systemin is transported to undamaged areas of the body where it interacts with receptor cells and initiates a cascade of biochemical reactions that result in compounds(jasmonic acid activates the insecticides) that act as insecticides.

Question 54

name at least 3 Barriers or impediments to herbivory or pathogens

Answer 54

waxy cuticle, spines, thorns, trichomes, bark, etc.,

Question 55

Plants also have evolved mutualistic relations with a host of animals that can help them deter predation. give example

Answer 55

parasitoid wasps that lay egg on catepillers back when catepiller attacks plant

Question 56

define secondary metabolites

Answer 56

ACT AS INSECTICIDES. If eaten, these chemicals have distasteful or toxic affects and either make the plant undesirable or outright kill the herbivore. These compounds repel, disrupt digestive processes, stop cellular respiration, or otherwise harm or kill the herbivore.Other secondary metabolites include pheromones, which might (1) warn neighboring plants (think lima beans and spider mites), or (2) send signals to insect predators of herbivores, e.g., parasitoid wasps.

Question 57

give example of secondary metabolites

Answer 57

canavanine: pretneds to ve arginine in insect proteins, which then malfunctions resulting in death of the insect.

Question 58

define allelopathy

Answer 58

type of secondary metabolites that release toxins into soil that affects growth of other plants, e.g., they block germination or inhibit growth. ex walnut

Question 59

define hypersensitive response

Answer 59

Plant receptors detect proteins from the pathogen, causing Stomata to close, production of toxic compounds that are specific to the pathogen attacking the plant, reinforcement of neighboring plant cells to limit spread of the pathogen, and suicide of cells in infected area resulting in death of the pathogen and brown spots on leaves

Question 60

define Systemic Acquired Resistance (SAR)

Answer 60

The hormone, Salicylic Acid, prepares the plant for attack that might occur at sites distant from the infected sites . methyl salicylate (MeSA) travels through phloem sap and leads to SAR throughout plant body. So, communication occurs among cells in disparate regions of the plant body to limit the severity of pathogenic infections.