Plants

plants test fal card. Ms.Stark

explain the importance of plants

* everymajor food group has been cultivated for 2k-4k years

Non vascular plants: example, environmnet, vascular tissue, leaf life, root like, size, reproduction

**Examples:**

Moss, Liver worts, Hornworts

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**Environment:**

Moist only

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**Vascular tissue:**

No vascular tissue (like open circulatory system)

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**Leaf like:**

Make glucose by photosynthesis

Glucose transported by diffusion

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**Root like:**

Anchor plant

Do NOT absorb water

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**Size:**

Low growing… for diffusions

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**Reproduction:**

Spores ->. Egg + pollen

Vascular plants: example, environment, vascular tissue, leaf life, root like, size, reproduction

**Examples:**

Ferns, Trees, flowers ect

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**Environment:**

Most or dry

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**Vascular tissue:**

Xylem transports water

Phloem transports food

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**Leaf like:**

Make glucose by photosynthesis

Has xylem and phloem

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**Root like:**

Tru roots

Absorbs water

Has xylem and phloem

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**Size:**

Can be vary tall due to vascular tissues

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**Reproduction:**

Seeds – Egg +pollen grow into embryo, seed coat, food source

Alternation of genertions

alternation of plant life cycle between a haploid and diploid stage

diploid=sporophyte

haploid= gametophyte

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nonvascular plants are usually seen in the gametophyte stage

vascular plants are usually seen in the sporophyte stage

which evolved first in vascular plants: spores or seeds?

spores - ferns are an early vascular plant since they still use water to distribute spores

explain the life cycle of plants

male and female gametophytes undergo mitotis to produce the gametes. gametes are distributed and fertilize eachother to make a sporophyte. sporophyt grows up and spreads spores that make gemtophytes.

benefits of seeds:

• contains food (cotyledon) for germination before photosynthesis

• embryo in seed contains immature root and shoot

• protected by seed coat

kinds of vascular plants

• gymnosperm

• angiosperm

difference between angio sperma nd gymnosperm

Gymno

\-          Non flowers

\-          Seeds are naed (not protected by fruit)

\-          E.g coniferous trees (have needs & cones)

\-          Pollen is windborn\\

\-          No leaves - needles



Angio



\-          Flowering

\-          E.g deciduous trees (lose their leaves every fall)

\-          Flowering produce fruit

\-          Seeds contained in fruit

\-          Pollen soread by insects

\-          leaves

kinds of angiosperms

• monocot

• dicot

Monocot (1 leaf)Dicot (2 leaves)

what is a cotyledon

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The cotyledon is a part of the embryo (in the seed) that provides \n nutrients to the seed prior to photosynthesis

visual differences in monocot and dicot

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is xylem dead cells or live cells?

dead

what is xylem made of

dead cells

tracheids

vascular elements

how to trachieds and vascula elements work togetehr in the xylem

they conduct water through “pits” in between them

what is the difference between sapwood and heartwood

sap - functional xylem

heart - non functional xyem

gymnosperm and angiosperm differene in xylem

gymno sperms only have tracheids

angisperms ahev tracheids and vascular elements - likely because they evolved later

what part of the plant brings in the most water

root hairs

is phloem alive?

yes

phloem is made of:

• live cells

• sieve tube elements

• companion cells

what does xylem do?

brings water up the plant

what does phloem do?

moves sucrose from areas of high concentration to low concentration

explaint he process of sugar movement in phloem

leaves make glucose → stored as starch in the leaf → sucrose being soluble in water → starch storage form in the roots

what si the purpose of the chagin of sucrose forms phloem

to maintain the moving of sucrose down the plant due to concentration.

sieve tube elements

conduct sucrose through plant

cells have no nucleus, golgi or ribosomes - makes space for the sugars

stays alive thanks to companion cells

companion cells

help load sucrose to sieve tube elements

carry out metabolic processes for sieve tube elements

transport nutrients across thin cell wall

what is a bryophyte

non vascular plants

mainly haploid / gametophyte

life cycle of a bryophyte

gametophyte germinated form haploid spore

spore grows into gametophore. sexes develop on seperate gametophores

after fertilization, zygote devides and grows itno sporophyte till atached tot he gametophyte

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sporophyte appears and remains attached and nutritionaly dependent on gametophyte

why do bryophytes need ot live in mois conditions

• Reproduction: rely on moisture to swim tot he agg using flagella

• have no waxy cuticle and can take water up the entire leaf like surface (have no roots for absorbtion)

why do ferns live in moist environments?

ferns have roots for absorption but rely on moisture for the sperm to swim to the egg as well as for the spores to germinate

how have vascular land plants adapted to life with less water?

• gametes do not need water for transport (wind/animals)

• seeds (no need for moist environments like ferns)

• waxy cuticle and stomata to protect against water loss

• vascular tissue in roots enable search for water

kinds of roots

• bulbous roots: store starch

• aerial roots / prop roots: above ground roots that ancor plant

• tap roots: roots modified for food storage

what is the prupose fo leaves

photosynthesis produces energy

purpose of flowers

reproductive structures: polination or fruitpollination

parts of the leaf cross section

upper/lower Epidermis, palisade mesophyll, spongy mesophyll, vascular bundle, xylem, phloem, stomata, guard cells

most visible difference between dicot and monocot leaf cross section

palisade only in dicot

functions of stomata

gass exchange + water loss regulation

fucntions of epidermis

• protect inner sensitive tissues of the plant

• protect plant from bacteria and fungi

what would you expect to find a lot of in th emesophyl and why? + on which side more?

chloroplats - photosysnthesis

\- palisade (near the top, more exporuse to sun)

why are there spaces in the mesophyl

• storage of carbon dioxide (tomata are closed, allows photosynthesis to continue to happen)

• oxygen collects ebfore being released

what deos the root cross secrion of a dicot look like

vascular bundle as the inner core, bound by the endodermis. xylem in a x or star

what si the pericycle in the root

surrounds the vascular bundle and within the endodermis

what can you find in the cortext cells

starch graniuels

why do roots not have a cuticle?

epidermis needs to absorm water minerals and nutrients

what inthe roots is one cell thick and aids with disffusion?

root hairs

what si pith

pith is the cotex like cells withint he endodermis ring in a monocot root

monocot vs dicot root

monocot has a ring of vascular bundles

dicot has core vascular bundle

parts fo the root

epidermis, cortex, endodermis, vascular bundle, percycle, (pith)

functions of the stem

• support the plant and hold it upright

• conduit for th evascular tissue

parts fo the stem

epidermis, cortex (grond tissue), vascular bundle, (pith), aslo andodermis but hard to find

what is foudn only in a monocot root and dicot stem?

Pith

disfference between monocot and dicot stems

scattered vascula bundles in monocot

pith in dicot

formula of photosynthesis im plants

energy (sunlight) + water + Carbon Dioxide = glucose + oxygen

loss of water through stomata called ….

transpiration

how muhc of water taken in by plnats is used for photsynthesis

1%

importans fo transpiration

provides \n 2/3 of atmospheric \n moisture that falls as \n precipitation on land

3 theories of water transport

• root pressur

• capillary action

• cohesion tension

root pressur ehtoery

plant roots build up pressure that pushes water upwards

but roots of tall trees would need so much pressure to push water tot he top and many tress ahd no measurable root pressure at all

what causes guttaion

root pressure

only happens in small plants

capillary action theory

polar nature of water will cling to the sides of tubes and rise/climb

but water can only climb 60-90cm in a very narrow tube

cohesion tension theory

water clinging to the sides

water molecules stick to eachother (cohesion) and as one evaporates out the stomata, it puls on another

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but, no explination for how this works in winder when tress haev no leaves

columns of water can eb easily broken

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factors that affect transpiration

·       Number one factor: amount sunlight

·       Amount of water avaible to plant – they close stomata

·       Temperature

·       Leaf shape (surface area to volume) (more surafe area, lose more water)

·       Waxiness of leaf cuticle

what is wilting?

Wilting is caused by temporary excess of transpiration over absorption at the roots

decidous vs coniferous tress in water retention

decidous : high surface areas, large, not waxy

coniferous: low surface areas, small, waxy

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decidous loses

meristem tissue

regions of active growth contain unidifferentiates cells that devide & develop into specialized tissue

type sof meristem

• aprical

• lateral

apical meristem

foudn in root and shoot tips

causes growth up and down

division of apical maristems causes growth of roots, leaves and flowers

lateral meristem

causes growht of tissue just ebneath the bark

growht of lateral meristem causes increased girth (width)

• vasculam cambium

• cork cambium

vascular cambium

makes xylem on the einner sid and phloem on the outer side

cork cambium

produces corck onthe outer side

how do you get smooth and wrinkled bark?

cork cambium grows as tree grows = smooth

cork camboum stops growing and tree gets bigger = wrinkled

annual rings - why?

light rings = summer (less think cell wall)

dark rings = fall (thicker cell walls - denser)

more rapid growht inthe summer

• more daylight hours

• soil and mineral are most desirable

• bilogucalreactions occur mor erapidly

grwoth slowest in winter

Tropism

directional growth responce of a plant to an environemnt stimuli

• photottropism

• gravitropis

• hyrdotropism

• thingmotropism

phototropism

growth or movement in response to ;ight

shaded side contains more auxin and grows longer which makes it bend int he direction of light

solar traking

imamture buds track the sun accros the sky

gravitropism

roots grow towrds gravity and shoots away from gravity

amyloplasts storage of starches in roots weighs them down forcign them to grow downwards

hydrotropism

water

thigmotropism

touch - towrds touch - tendrils of sweet peas

nastic movement

mimosa, sundew

photoperiodism

grwoth or movement in responce to changes in length of natural daylight

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flowering only when days are long or only when days are shortnenng

growth promoters

auxin, gibberellins, cytokinins

gorwth inhibitors

abscisic acid, ethylene

auxins

Promote cell elongation, \n suppress leaf drop (once auxin \n levels decrease, leaves drop in \n the fall)

gibberellins

Increase stem length (produce taller, \n stronger plants), increase fruit size

cytikinins

Promote cell division & differentiation

Abscisic Acid:

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Abscisic Acid: Block intake of CO2 by causing stomata to \n close, inhibit seed germination, inhibit growth of lateral buds

Ethylene:

Ethylene: gas that stimulates aging of plant tissues, \n stimulates ripening & sweetening of fruit, speed up \n dropping of leaves

primary and secondary xylem

primary xylem is from the first growth - vertical

secondary xylem is from the seconda stahe of grawth - lateral

bark

phloem, cotex, cork cambium and cork

wood

primary and secondary xylem

vegetative reproduction

is a form of asexual reproduction that is from a fragment of the plant

• adventitious roots

• stolon / runner

• buds

• leaf

• cuttings

what are the reporductive organs of angiopersms vs gymnoperms

flower vs cones

what are the male and female parts of the flower

male - stamen / androecium

female - carples /pistil - gynoecium

difference between self polinating and cross polination

Self-pollination is where the plant’s own pollen fertilizes its egg, \n cross-pollination is when the pollen from another plant (of the same \n species) fertilizes its egg

different kinds of pollination methods

• air - birch

• flowers to attract polinators

ways that fruit/seeds are disperesed

wind - dandelion

attachment - burr

distruption - touch me nots

ingestion - blueberies

displacement - acorn

currents - coconuts

artificail axeula reproduction

• grafting

• cutting

• layering

• micropropagation

what is mass extinction

Extinctions of species on a massive proportions (ie a large percentage of species alive at \n the time going extinct). This alters the course of evolution

succession

a series of events by whihc life comes back