Chapter 30: Plant Structure and Function

What does the plant shoot system consist of?

stems, leaves (vegetative/photosynthetic), flowers, fruits (reproductive); above ground

What does the plant root system consist of?

roots; absorbs water and minerals, structural support

What is meristematic tissue in plants?

actively dividing, undifferentiated cells that give rise to all other plant tissues

What is the apical meristem and its function?

tips of roots and shoots; vertical growth

What is the lateral meristem and its function?

along sides of stems and roots; growth in thickness

What is the intercalary meristem and where is it found?

in monocots at bases of leaves, allowing leaves to grow from base

What is non-meristematic (permanent) tissue?

non-dividing, differentiated cells perform specialized functions

What are the three types of non-meristematic tissue?

dermal, vascular, ground tissue

What is dermal tissue?

single outer layer of the plant/epidermis; provides protection and regulation; stomata for gas exchange

Each stoma in the dermal tissue is surrounded by

two guard cells that control opening/closing

What is vascular tissue?

xylem and phloem; transports water from roots to plant and transports sugars to all areas

Vascular bundles in perennial plants grow to form

a growth ring

What is ground tissue in stems?

interior of vascular tissue; site of photosynthesis, support, storage

What are the two types of stems?

herbaceous (soft) and woody

What are the main functions of stems?

provide support to the plant, hold leaves and flower/fruit, connect to root system

Are stems branched or unbranched?

may be either

What are nodes and internodes in a stem?

nodes—points on stem where leaves or branches attach

internode—segments between nodes

What is the petiole?

stalk of a leaf that attaches it to the stem

Where is the axillary bud located?

between petiole and node, can develop into branches or flowers

Why do some plants have modified stems?

aid in growth, asexual reproduction, storage, structural support

What are underground stem modifications for growth or asexual reproduction?

rhizomes, corms, stolons

What are underground stem modifications for storage or asexual reproduction?

tubers and bulbs

What are aerial stem modifications and what are their purposes?

tendrils—structural support

thorns—protection

What is primary growth in stems?

vertical growth at shoot/root apical meristem

What is secondary growth in stems?

growth in thickness due to lateral meristem; only in woody plants

Where is the vascular cambium located, and how does it divide?

between primary xylem and phloem; divides to form secondary xylem/phloem, increasing stem thickness

What is special about secondary xylem cells?

contain lignin, providing strength and support

What is the cork cambium, and what does it produce?

outside vascular cambium; produces cork cells containing suberin for protection

How are annual rings in woody plants formed?

seasonal growth of vascular cambium produces secondary xylem, creating annual rings

What are the two types of roots?

taproot and fibrous

Which plant has a fibrous root system?

monocots; dense network of roots close to surface

Which plant has a taproot system?

eudicots; main root grows deep into soil; lateral fibrous roots grow off it

What are the purposes of root modification?

underground storage (carrots, parsnips, beets)

aerial roots for support/anchoring (gas exchange)

What is the purpose of dermal tissue in roots?

protection and absorption of water

How do root hairs influence absorption?

increases surface area for absorption

What is vascular tissue shape in roots?

monocots - ring

eudicots - X-shape

What is the purpose of ground tissue in roots?

used for storage

What develops into the root system during seed germination?

radicle of seed

What protects tip of growing root?

root cap

What are the three zones of primary root growth?

Cell Division Zone—closest to root tip, actively dividing cells near root tip; root growth

Elongation Zone—cells increase in length, increasing root length

Maturation Zone—cells differentiate; root hairs first appear here

What is the lamina of a leaf?

leaf blade, widest part of the leaf; connected to petiole which connects to stem

What is the margin of a leaf?

the outer edge of a leaf

What is the midrib of a leaf?

The main vein carrying vascular tissue from petiole to leaf tip; branches to form veins

What venation pattern do monocots have?

parallel venation

What venation pattern do eudicots have?

reticulated/netted venation

What are cold environment adaptations of leaves?

reduced in size, needle-shaped, less surface area and sunken stomata; reduced water loss, no snow build up to protect stem from breaking

What are desert adaptations of leaves?

leaves reduced to spines and no chloroplasts for defense; stems succulent and contain chloroplasts; water conservation

What are the tissue types that leaves have?

dermal, ground, vascular

What is the purpose of ground tissue in a leaf?

site of photosynthesis; located in mesophyll tissue below epidermis

What are the two types of mesophyll cells and their structures?

palisade parenchyma—vertical, column-shaped, tightly packed cells

spongy parenchyma—irregular-shaped, loosely packed cells allowing gas exchange

What are the main cell types in xylem?

vessel cells or tracheids, conduct water

What is an alternate leaf arrangement?

one leaf per node

What is an opposite leaf arrangement?

two leaves per node

What is a whorled leaf arrangement?

three or more leaves per node

What are the different shapes and types of leaves?

simple and compound

What is a simple leaf composed of?

a single undivided blade or lamina; leaf blade divided into lobes but lobes do not touch midrib

What is a compound leaf composed of?

completely divided leaf blade

What is a palmate leaf?

compound leaf with leaflets all originating from the same attachment point (petiole)

What is a pinnate leaf?

A compound leaf with leaflets arranged along a rachis (from midrib)