DAT bio Chapter 10 plants

Question 1

Endosperm:`

Answer 1

storage material, provides the

embryo with nutrients.

Question 2

Embryo: consists of 4 parts:

Answer 2

Radicle: first to emerge, develops into root,
anchors the plant into soil.
● Hypocotyl : bottom region of young shoot.
● Plumule: develops into leaves.
● Epicotyl : top region (shoot tip).

Question 3

What is Germination

Answer 3

the sprouting of a seedling from a
previously dormant state when environmental
conditions are favorable. Water is the most
important condition. The seed absorbs water
(imbibition) which breaks the seed coat and
initiates growth

Question 4

Plant growth takes place via mitosis at ______

Answer 4

meristems

Question 5

What is primary growth

Answer 5

s vertical growth occurring at
apical meristems (located at tips of roots and
shoots). Occurs before secondary growth

Question 6

Primary growth (Root Growth: root cap covers roots protecting the
apical meristem. The root tip has three zones: Name them

Answer 6

Zone of division: where apical meristem cells
are located and divide.
Zone of maturation: cells differentiate to
specific plant tissue

Zone of elongation: above apical meristem,
cells absorb water and elongate.

Question 7

Secondary growth

Answer 7

is horizontal growth occurring
at lateral meristems (vascular cambium and
cork cambium). Only occurs in woody plants

Question 8

Vascular cambium

Answer 8

a ring of meristematic tissue
located between primary xylem (closer to center)
and primary phloem (closer to outer edge). Cells
produced inside the ring of vascular cambium
become secondary xylem (forms wood along with
pith) and cells outside become secondary phloem
(forms bark with cork and cork cambium). New
xylem is produced every year (forming growth
rings) whereas new phloem replaces old phloem.

Question 9

Cork cambium

Answer 9

a ring of meristematic tissue
located outside the phloem. Produces cork, the
outermost protective layer.

Question 10

Ground tissue

Answer 10

provides structural support,

makes up most of the plant’s mass

Question 11

Three parts of ground tissue

Answer 11

Parenchyma: filler tissue, makes up the
bulk of plant, thin cell walls.
Collenchyma: extra support (e.g. in areas
of active growth), irregular cell walls.
Sclerenchyma: provides main structural
support, thick cell walls.

Question 12

Vascular tissue:

Answer 12

transports materials from a
source to a sink (source to sink theory). The
stele is formed by xylem, phloem, and the
pith (made of parenchyma) in the center of the
plant for transport.

Question 13

What does phloem transport?

Answer 13

: transports sugars from leaves
(source) to roots and other areas (sink).
Made of sieve cells (long cells, lacking
organelles, connected to form a tunnel for
transport) and companion cells which are connected to sieve cells, contain organelles
for metabolic functions).

Question 14

What does xylem transport?

Answer 14

\: transports water from roots
(source) to leaves (sink) and provides
structural support. Made up of tracheids
(long and thin, water travels through pits in
their tapered ends) and vessel elements
(short and stout, water travels via
perforations in cell walls).

Question 15

Dermal tissue

Answer 15

outer layer of the plant.

Provides protection and regulation.

Question 16

expanding on dermal tissue:

what is epidermis

Answer 16

Epidermis: covered by cuticle (waxy layer)

which limits water evaporation.

Question 17

expanding on dermal tissue:

what is root hairs

Answer 17

increase surface area of roots

for greater nutrient and water uptake.

Question 18

Water uptake in the roots happens using what pathway?

Answer 18

symplastic pathway (inside the cell’s cytoplasm)

Question 19

Water uptake in the roots occurs via the
symplastic pathway (water movement through the cell’s cytoplasm)
or the __________ pathway

Answer 19

apoplastic pathway ( water movement outside the cell, but within the cell wall.

Question 20

What is the casparian strip

Answer 20

(made of
fat and wax) is an impenetrable substance in the
cell walls of the roots. It forces water coming from
the cell walls (outside) into the cytoplasm of the root cells for filtering before
entering the rest of the plant.

Question 21

Stomata are
_____ when CO2 concentration is low (allows for CO2
intake and photosynthesis) and ______ when CO2
concentrations are high and when temperatures
are high (prevents water loss via transpiration).

Answer 21

Open, closed

Question 22

Palisade mesophyll

Answer 22

closer to upper
epidermis, tightly packed cells that carry out
photosynthesis.

Question 23

spongy mesophyll

Answer 23

closer to lower epidermis,

loosely-packed allowing for gas exchange.

Question 24

Bundle sheath cells do what

Answer 24

surround and protect the

vascular bundle

Question 25

(movement of water) Cohesion-tension theory:

Answer 25

: transpiration, the driving force, causes water to evaporate from the stomata and leads to a transpirational pull . This cohesive force (between similar substances, e.g. the water molecules) pulls the water column upward.

Question 26

(movement of water) | Capillary action:

Answer 26

an adhesive force (between dissimilar substances) due to attraction between water and xylem vessels that causes water to climb upwards

Question 27

(movement of water) | Root pressure:

Answer 27

builds up in roots to produce an osmotic gradient which drives water from soil into the roots

Question 28

(movement of food) | Pressure flow hypothesis:

Answer 28

source cells produce sugar and load it into phloem → increased sugar concentration creates a gradient that pulls water into phloem → turgor pressure in phloem increases, resulting in bulk flow movement of sugar from leaves down to roots`

Question 29

Plant hormones: | ethylene

Answer 29

gas that increases fruit ripening.

Question 30

Plant hormones: | auxins

Answer 30

cause cell growth. Work with cytokinins. Responsible for plant tropisms (growth in certain directions). Auxin concentrated on one side of a stem leads to asymmetric growth.

Question 31

Phototropism

Answer 31

growth towards light.

Question 32

Gravitropism

Answer 32

growth away from pull of | gravity.

Question 33

Thigmotropism

Answer 33

growth in response to | contact (e.g. vine growing up a wall)

Question 34

Cytokinins

Answer 34

regulate cell differentiation and | division with auxins. Can prevent aging.

Question 35

Gibberellins

Answer 35

responsible for stem and shoot elongation, elimination of dormancy of a seed, flowering, fruit production, leaf and fruit death.

Question 36

Abscisic Acid:

Answer 36

: functions during stress. Promotes dormant seeds, closes stomata (drought), inhibits growth.

Question 37

Alternation between diploid and haploid.

Answer 37

Two haploid gametes fuse producing diploid zygote → zygote becomes sporophyte via mitosis → in their sporangia, sporophyte undergoes meiosis to produce haploid spores → spore becomes gametophyte via mitosis → gametophyte produces gametes → cycle repeats.

Question 38

Homosporous plants:

Answer 38

bisexual gametophyte, | produces one type of spore

Question 39

Heterosporous plants:

Answer 39

produce two types of spores; microspores (male) and megaspores (female).

Question 40

(bryophytes) | Nonvascular plants

Answer 40

therefore are small and short. Found in moist habitats, grow horizontally to remain close to water and nutrients. Contain rhizoids (hair-like projections) which aid in water absorption and minor anchorage

Question 41

nonvascular plants

Answer 41

mosses, hornworts, | liverworts

Question 42

Majority of their life cycle is spent in what stage

Answer 42

; they have a reduced sporophyte which depends on and is attached to the gametophyte.

Question 43

Tracheophytes | are what

Answer 43

vascular (contain xylem and phloem), allowing them to grow vertically and tall and have a root system for anchorage. Most of the life cycle is spent in the sporophyte stage

Question 44

Seedless tracheophytes:

Answer 44

(lycophytes and pterophytes, e.g. club moss, quillworts, fern, horsetail). Mostly heterosporous with flagellated sperm (can move on their own).

Question 45

Seed-bearing tracheophytes

Answer 45

all heterosporous

Question 46

Gymnosperms:

Answer 46

The first seeded plants. Seed not protected. E.g. conifers such as firs, spruce, pine, redwood. Sperm is not-flagellated and is dispersed in seeds by wind.

Question 47

Angiosperms:

Answer 47

Most abundant plant. Flower-bearing and fruit-producing (plant ovary, protects seeds). Sperm is not-flagellated and is dispersed by wind or animals often as pollen. Can exhibit double fertilization (female gamete fertilized by two male sperm).

Question 48

Petals do what

Answer 48

attract animals to achieve pollination

Question 49

stamen is what

Answer 49

male plant sex organ. Composed of anther (site of microspore formation) and filament (supports anther).

Question 50

microspore undergoes what _______

Answer 50

mitosis to form generative cell (contains sperm) and tube cell which combine to form pollen

Question 51

Pistil :

Answer 51

female plant sex organ. Composed of stigma (top), style (tube leading to ovary), and ovary (contains ovule or egg)

Question 52

Steps for fertilization

Answer 52

``` Pollen lands on stigma → tube cell elongates down style forming pollen tube → generative cell travels down pollen tube to ovary → splits forming two sperm cells (double fertilization) ```

Question 53

One sperm cell meets ovule to form the _____. Ovary develops into _____, which is eaten by animals and deposited in a new location (gene migration)

Answer 53

seed or embryo, | fruit

Question 54

the other sperm cell combines with ovule’s | ______ to form the _____

Answer 54

polar nuclei | endosperm

Question 55

Cotyledons

Answer 55

first leaves to appear on seedling. Contain nutrients from seed to feed the growing seedling

Question 56

Monocotyledons (monocots)

Answer 56

``` single cotyledon long narrow leaf paralell veins vascular bundles scattered floral parts in multiples of 3 ```

Question 57

Dicotyledons

Answer 57

``` Two cotyledon broad leaf network of veins vascular bundles in a ring floral parts in multiples of 4 or 5 ```

Question 58

Plants have a symbiotic relationship with what

Answer 58

nitrogen fixing bacteria

Question 59

Bacteria fixes atmospheric nitrogen into what

Answer 59

usable form for plants, in return, plants produce food for bacteria using photosynthesis

Question 60

Nitrogen fixation (nitrogen fixing bacteria) step 1

Answer 60

(in root nodules of legumes) fix atmospheric nitrogen (N2 ) to ammonia (NH3 ) and ammonium (NH4 + ).

Question 61

Nitrogen fixation (nitrifying bacteria) step 2

Answer 61

convert ammonia and ammonium to nitrites (NO2 - ) and then to nitrates (NO3-

Question 62

Nitrogen fixation | step 3

Answer 62

Nitrates are taken up by plants (assimilation of nitrogen) and incorporated into amino acids and chlorophyll. Animals (consumers) acquire nitrogen by eating plants (producers)

Question 63

Nitrogen fixation step 4 Detritus

Answer 63

dead decaying plants and animals | provides soil with nitrates.

Question 64

Nitrogen fixation step 5 Denitrifying bacteria

Answer 64

convert nitrates back to | atmospheric nitrogen