Clemson Plant Bio Exam 4

Apical Meristem

area of new cell generation that go on to differentiate into 1 of 3 primary meristems

Name the Primary meristems produced from the Apical meristem

Ground meristem

Protoderm

Procambium

What tissue system does the Ground Meristem produce

Ground tissue system

What tissue system does the protoderm produce

Dermal tissue system

What tissue system does the procambium produce

Vascular tissue system

Simple tissue

Tissues comprised of only 1 cell type

\-Collenchyma

complex tissue

Tissues comprised of multiple cell types

\-phloem

Tissue

Groups of cells that are structurally or functionally distinct

Tissue system

Groups of tissues organized into a structural or functional unit

Plant tissue systems

Dermal tissue system

Ground tissue system

Vascular tissue system

What tissues make up the Dermal tissue system

Epidermis

Periderm

What tissues make up the Ground tissue system

Parenchyma

collenchyma

sclerenchyma

What tissues make up the Vascular tissue system

xylem

phloem

Parenchyma

\-Most numerous cells in plant body

\-Alive at maturity

\-have thin primary walls

\-Function in photosynthesis, storage, secretion, and regeneration

Parenchyma cells in plant body and their function

* Cortex & pith of stems and roots
* used for storage
* Mesophyll of leaves
* photosynthesis
* Flesh of fruit
* Vertical strands in primary Xylem and phloem
* Rays in secondary xylem
* Transfer cells

Collenchyma

Supports young growing organs

* Mainly found just under epidermis
* Have cellulose primary walls with thickened corners
* Usually NOT found in roots or in monocot stems and leaves

Where won’t you generally find Collenchyma cells?

* Roots
* Monocot stems and leaves

Sclerenchyma

Strengthens and supports plant parts that are no longer elongating

* Dead at maturity
* Thick secondary wall of lignin
* Made up of fibers and sclereids

Fibers

Long, thin cells that occur in strands or bundles

Sclereids

Irregularly-shaped individual cells; occur singly or in aggregates

Phloem

Transport of sugars and many other compounds

* Sieve cells in gymnosperms
* Sieve-tube elements in angiosperms
* Sieve elements in everything else
* Living

Xylem

Transport of water and minerals

* Tracheary elements
* tracheids
* vessel elements
* Dead at maturity

Stele

Central cylinder of the root or stem where xylem and phloem are located; may also contain pith

mesophyll cells

Chloroplast-containing, photosynthetic parenchyma cells found in leaves

pith

Central column of ground tissue in the center of the stele

Epidermis

Outer layer of cells on a plant’s body used for protection

* Cells closely packed
* Secretes waxy cuticle
* Contains specialized cells:
* Trichomes
* Guard cells

Specialized cels of Epidermis

Trichomes

Guard cells

Trichomes

Hair-like projections on epidermis

Guard cells

Control stomatal opening

What does the epidermis secrete to prevent water loss?

Cutin

Tracheids

Single, elongated cells used in water transport

Vessel elements

Present in many angiosperms in combination with tracheids

2 components that make up phloem

Sieve cells

Sieve tube elements

5 main functions of roots

1. Anchors
2. Absorbs water
3. Conducts water and minerals
4. Cundicts hormones and secondary metabolites
5. Clonal regeneration

Name of first root to develop

Radicle

Tap root system

One main, deep penetrating root with lateral roots branching off it

* Taproot born from radicle

Fibrous root system

No main taproot; no one root is more prominent

* Roots are stem born; **adventitious roots**
* Do not penetrate as far as taproot

Where are most roots located

underground

Where does most water and mineral absorption happen in the roots?

Fine roots

In a fibrous root system, the primary root is _________ lived

Short

Root cap

Mass of living parenchyma cells that protects the root apical meristem

Quiescent center

Pool of stem cells (initials) within the root apical meristem

Promeristem

Area with small, many-sided initial cells, base of the apical meristem where it meets the root cap

The promeristem goes on to form what structure?

quiescent center

How is the root cap able to sense and respond to gravity?

Statolith cells act like free pebbles that “roll around” in response to gravity

\-Auxin hormone stimulates growth on one side of root in response to statolith position

Statoliths

“stationary stone”

Pebbles in a jar; respond to gravity; how plants figure out where “down” is

Auxins

Growth hormone used in various parts of plant

\-In root, its produced on one side of root in response to statolith position

3 Root zones

* Zone of cell division
* Zone of elongation
* Zone of maturation

Casparian strip

Gives the plant greater control over what comes into the plant body and is moved by the vascular tissue

* Attach tightly to the plasma membrane of cells forcing water to move symplastically through the living components of the cell

Cortex

Ground tissue; mostly parenchyma

Endodermis

Innermost cell layer of cortex

* barrier to apoplastic movement of water and solutes with aid of casparian strip

Vascular cylinder

Innermost part of root where the vascular tissue is located

Pericycle

surrounds the vascular cylinder – lateral roots arise from it

What role does the casparian strip play in water movement?

Allows plant to regulate what fluid does and doesnt pass into/out of vascular cylinder

Where do lateral roots arise from (be able to label this)

Pericycle

3 types of specialized roots

* Adventitious roots
* Pneumatophores
* Storage roots

Adventitious roots

roots arising from stem

Pneumatophores

“air roots”

Storage roots

tubers and the like

Bulbs

Modified leaf for food storage

Corms

Modified stem for food storage

Phytomere

* Node
* Leave
* Internode
* Bud

Shoot

Leaf + stem

node

area of stem where leaf sprouts out just below the bud

internode

area between nodes

Leaf primordia

protects shoot apical meristem

Tunica

Outermost layer(s) of cells on shoot apical meristem

Corpus

beneath the tunica layer

Anticlinal Division

perpendicular division; cells divide side by side

Periclinal division

Parallel division; cells divide on top of each other

* adds bulk

what kind of cell division gives rise to the tunica?

Anticlinal

what kind of cell division gives rise to the corpus?

Periclinal

3 zones of shoot apical meristem

Rib Zone

Central zone

Peripheral zone

3 layers of shoot apical meristem

2 Tunica; One Corpus

Rib zone

Gives rise to internal tissues of stem

Central zone

Replenishes peripheral and rib zones

peripheral zone

gives rise to leaf primordia

Most eudicots have shoot apical meristems with 3 layers; 2 _____ layers, and 1 _____ layer

Tunical; Corpus

Layer 1 (L1)

* Anticlinal division
* Gives rise to Epidermis

Layer 2 (L2)

* Anticlinal division
* Gives rise to internal tissues

Layer 3 (L3)

* Periclinal division
* Gives rise to internal tissues

components of the vascular bundle in eudicots

* Bundle cap
* parenchyma
* sclerenchyma
* Primary phloem
* Vascular Cambium
* Primary xylem

How are vascular bundles arranged in eudicots?

In a ring

How are vascular bundles arranged in monocots?

Randomly arranged

3 main stem types

Siphonostele-like eustele

Eustele with discrete bundles

Monocot stem

Describe a Siphonostele-like eustele

Vascular cylinder is near-fully connected around pith

* narrow interfascicular region

Describe a Eustele with discrete bundles

Vascular bundles arranged in a cylinder, but not connect

* Wide interfascicular regions
* Cortex and pith are distinct, but connected

Describe a monocot stem

The vascular bundles occur in multiple rings of bundles OR scattered throughout the ground tissue

* Ground tissue is NOT separated into cortex and pith

What is the most common stem type for eudicots?

Eustele with discrete bundles

Herb

* Herbaceous
* Stems not persistent
* Dies back to the ground at the end of the growing season
* Little to no secondary growth

Vine

* Herbaceous
* Stem climbing (tendrils, holdfast, or adventitious roots) or twining
* Little to no secondary growth

Shrub

* woody
* several stems from the base
* less than 25' tall.
* Secondary growth

tree

* woody
* usually one main stem
* usually more than 25' tall
* much secondary growth

in shrubs and trees, secondary growth results in the production of what?

woody tissue

Where does secondary growth in the stem take place

vascular and cork cambium

Annual plant

Lives for 1 yr/season

Biennial plant

Lives for 2 yrs/season

Perennial plant

lives for several to many years/seasons

Deciduous plant

Leaves die off in cold season

evergreen plant

Leaves persist for 2+ seasons