lecture 3 plant anatomy

shoot system

leaves for photosynthesis

stem supports plant and transports water and minerals by vascular system

• nodes and internodes

• terminal/apical bud and lateral/axillary buds for growth

flowers for reproduction

root system

anchors plant and stores nutrients

brings in water and minerals

• root hairs increase surface area

3 types:

• adventitious - from stems (strawberries)

• taproot - tapering root (shrubs, carrot)

• fibrous - thin, spread out roots (grasses)

Parenchyma cell

least specialized

no secondary cell wall

thin primary cell wall

holds water and stores nutrients in large central vacuole

location of most metabolism to support plant

Collenchyma cells

no secondary cell wall

more rigid primary cell wall

important in support of young plants and stems of nonwoody plants

capable of elongation

Sclerenchyma cells

secondary cell wall containing lignin

dead tissue, but important in support

found in areas that have stopped growing

fossil fuels

epidermis

protection, but can be more specific

single layer of tightly packed cells, effectively skin

leaves and sometimes stems have cuticle

periderm

replaces epidermis during secondary growth

the cork and cork cambium

dead tissue

arises from ground meristem

xylem

dead at maturity

transports water up from the roots

contains tracheids and vessel elements in angiosperm

phloem

transports sucrose and some mineral ions throughout the plant, both up and down

contains sieve tube cells and companion cells that coordinate function of sieve tube cells

ground tissue

aka pith or cortex depending on location

usually made up of parenchyma cells

located between dermal and vascular tissues

acts in photosynthesis, storage, and support

indeterminate growth

continues throughout entire life of organism

in plants, occurs at meristems via mitosis and cell elongation

determinate growth

occurs until organism reaches a certain size

in humans, occurs in hte long bones until maturity is reached during mid to late teens up to early 20s

protoderm

turns into epidermal tissue

procambium

turns into vascular tissue

ground meristem

turns into ground tissue and periderm

apical meristem

located at root and shoot tips

responsible for primary growth

root cap

protects apical meristem of the root

secretes slimy substance to help lubricate root as it moves

lateral meristem

seocondary growth from cork cambium in woody perennial dicots

epiderms is replaced by periderm

cork cambium produces phelloderm and cork, and waxy substance suberin thats added to cork

cork cambium, phelloderm, and cork are periderm

bark is periderm and phloem

coleus stem tip

pyrus root tip

zone of cell differentiation/maturation

major tissue types present, contains root hairs and lateral rotos

zone of elongation

cells take in water and elongate

zone of cell divsion

growth via mitosis

ranunculus root

zea root

helianthus tem

epidermis, cortex, vascular bundles, pith

xylem is closer to pith, phloem to epidermis

tilia woody stem

older xylem forms non func heartwood

newer xylem forms func sapwood

xylem added seasonally - rings

zea mays stem

epidermis, ground tissue, vascular bundles

vascular are scattered

phloem always external to xylem

annuals

a year or less for germination to death

biennials

live two years, one for vegetative growth and next for flowering

pernnials

live many years before dying of disease or injury

monocots vs dicots

leaf epidermis

trichomes, guard cells, stomata

syringia leaf

leaf model

zea leaf

pinus leaf

monoecious plants

stamen and carpel

dioecious plants

either stem or carpel, one plant could have flowers with both

perfect flowers

stamens and carpel

imperfect flowers

either stemsn or carpel

complete flowers

sepals, petals, stamens, and carpel

incomplete flowers

missing sepal, petal, stamen, and/or carpel

aggregate

rasp and blackberry

multiple

pineapple, mulberry, fig

pome

apple, pear

drupe

cherry, peach, almond, olive

legume

beans, peas, soybeans, peanut

hesperidium

orange, lemons, grapefruitp

pepo

squash, cucumber, watermelon

berry

grape, tomato, peppers

grain

wheat, corn, rice

achene

sunflower

accessory

strawberry

nut

oat, hickory

sumara

ash, maple, elm

capsule

okra