bio232 test 1

Physiology

how plants carry out functions

Morphology

physical form, exterior structure

Anatomy

smaller, more microscopic-level internal structure

Interdeterminate growth

unlike animals, plants continue to grow throughout their lives

Angiosperms

flowering plants

Taproot

large, vertical main root of a plant’s root system

Lateral roots

plant root that extends horizontally from another root

Perennial

root system lives for many years

Phenotypic plasticity

root form is exchangeable, depending on environmental conditions

Adventitious

roots develop from the shoot system instead of the root system

Pneumatophores

aerial root specialized for gas exchange

Storage roots

specialized for storing carbohydrates and other nutrients

Stems

above ground structures that make up the shoot system

Nodes

part of plant where leaves are attached

Internodes

segments between nodes

Petiole

stalk of the leaf

Stolons

modified stems that grow horizontally along soil surface

Tubers

underground, swollen rhizomes that function as carbohydrate storage organs

Transpiration

loss of water above ground plant parts (mostly though stomata)

Dermal tissue system

tissue forming the outer layer of a plant; also called the epidermis

Cuticle

waxy layer that forms a continuous sheet on the surface of leaves and stems.

Guard cells

1 of 2 specialized, crescent-shaped cells forming the border of a plant stoma. They change shape to open the stoma.

Trichomes

hair-like appendages made up of specialized epidermal cells

Ground tissue system

includes tissue/cell type sparenchyma, collenchyma, and sclerenchyma.

Totipotent

capable of dividing and developing to form a complete, mature organism.

Callus

a mass of undifferentiated cells that can generate roots and other tissues necessary to create a mature plant.

Fibers

elongated sclerenchyma cell that provides support to vascular tissue.

Sclereids

short type of sclerenchyma that usually functions in protection.

Primary Cell wall

the outermost larer of a plant cell wall, made of cellulose fibers and gelatinous polysaccharides, that defines the shape of the cell and withstands the turgor pressure of the plasma membrane.

Secondary cell wall

the thickened inner layer of a cell wall formed by certain plant cells as they mature and after they have stopped growing; contains lignin in water conducting cells. Provides support or protection.

Simple Tissues

A tissue consisting of a single cell type.

Complex tissues

A tissue consisting of two or more cell types.

Vascular tissue system

In plants, tissues that transport water, nutrients, and sugars. Made up of the complex tissues xylem and phloem, each of which contains several cell types.

Xylem

conducts water and dissolved nutrients in one direction

Phloem

conducts sugar, amino acids, hormones, and other substances in two directions

Tracheids

in vascular plants, a long, thin, water-conducting cell that has pits where its lignin-containing secondary cell wall is absent, allowing water movement between adjacent cells.

Vessel elements

in vascular plants, a short, wide, water-conducting cell that has gaps through both the primary and secondary cell walls, allowing the unimpeded passage of water between adjacent cells.

Pits

In plants, a small hole in the secondary cell walls of tracheids and vessel elements that allows passage of water.

Perforations

in plants, a small hole in the primary and secondary cell walls of vessel elements that allows passage of water.

Hardwood

woods, typically from angiosperms, characterized by the presence of vessel elements.

Softwood

wood, typically from conifers, characterized by the presence of tracheids (but lacking vessel elements).

Sieve-tube elements

in plants, an elongated sugar-conducting cell in phloem that lacks nuclei and has sieve plates at both ends, allowing sap to flow to adjacent cells.

Sieve plates

in plants, a pore-containing structure at each end of a sieve-tube element in phloem.

Companion cells

in plants, a cell in the phloem that is connected via many plasmodesmata to adjacent sieve-tube elements. Companion cells provide materials to maintain sieve-tube elements and function in loading and unloading of sugars into sieve-tube elements.

Meristems

populations of undifferentiated cells that retain the ability to undergo mitosis.

Apical meristems

divide, enlarge, and differentiate, root and shoot tips extend the plant body outward, allowing it to explore a new space.

Primary growth

In plants, in increase in the length of stems and roots due to the activity of apical meristems.

Primary plant body

All of the cells and tissues derived from apical meristems and primary meristems.

Primary meristems

in plants, three types of partially differentiated cells that are produced by apical meristems

Protoderm

the primary meristem tissue on the exterior later of a young plant embryo that fives rise to the dermal tissue, or epidermis.

Ground meristem

A primary meristem tissue that gives rise to the ground tissue system.

Procambium

a primary meristem tissue that gives rise to the Vascular tissue.

Root cap

Group of cells that protects the root apical meristem.

Zone of cellular division

contains the apical meristem, where cells actively divide, along with the protoderm, ground meristem, and procambium, where additional cell division occurs.

Zone of cellular elongation

made up of cells that are recently derived from the primary meristems and that increase in length.

Zone of cellular maturation

where older cells complete their differentiation into dermal, vascular, and ground tissues.

Root hairs

a long, thin outgrowth of epidermal cells of plant roots, providing increased surface area for absorption of water and nutrients.

Vascular bundles

a cluster of xylem and phloem strands that run the length of the stem.

Pith

in the shoot system, ground tissue located to the inside of the vascular bundles. Roots of some plants also have a pith.

Cortex

a layer of ground tissue found outside the vascular bundles of roots and outside the pith of a stem.

Secondary growth

in plants, an increase in the width of stems and roots due to the activity of a cambium.

Wood

Xylem resulting from secondary growth; forms strong supporting material. Also called secondary xylem.

Cambium

In woody plants, tissue that consists of two types of cylindrical meristems that increase the width of roots and shoots through the process of secondary growth.

Vascular cambium

one of two types of cylindrical meristems, consisting of a ring of undifferentiated plant cells in the stem and root of woody plants; produces secondary xylem (wood) and secondary phloem.

Secondary xylem

Xylem cells that are formed specifically from the vascular cambium and are therefore considered secondary growth.

Secondary phloem

phloem cells that are formed from the vascular cambium and are there for considered secondary growth.

Cork cambium

one of two types of cylindrical meristems, consisting of a ring of undifferentiated plant cells in the stem and root of woody plants; produces cork.

Cork

the main tissue associated with tree bark; produced by, and exterior to the cork cambium.

Cork cells

a cell in the protective outermost layer of a woody stem and root that produces and accumulates waxes that make the cell less permeable to water and gases.

Bark

the protective outer layer of woody plants, composed of cork cells, cork cambium, and secondary phloem.

Lenticels

spongy segment in bark that allows gas exchange between cells in a woody stem and the atmosphere.

Heart wood

the older xylem in the center of an older stem or root containing protective compounds and no longer functioning in water transport.

Sapwood

the younger xylem in the outer layer of wood of a stem or root, functioning primarily In water transport.

Dormancy

A temporary state of greatly reduced metabolic activity and growth in plants or plant parts.

Dendrochronology

the dating and study of annual growth rings.

Photosynthesis

the use of sunlight to manufacture carbohydrates.

Autotrophs

any organism that can synthesize reduced organic compounds from simple inorganic sources such as carbon dioxide or methane. (also called primary producer).

Heterotrophs

any organism that cannot synthesize reduced organic compounds from inorganic sources and that must obtain them from other organisms. (also called consumer).

Calvin Cycle

the set of reactions that uses NADPH and ATP formed in the light-capturing reactions to drive the fixation of CO2, reduction of the fixed carbon to produce sugar, and regeneration of the substrate used to fix CO2.

Thylakoids

a membrane-bound network of flattened sac-like structures inside a plant chloroplast that functions in converting light energy to chemical energy. Stakes of thylakoid discs make up grana.

Lumen

the interior space of any hollow structure or organ.

Stroma

the fluid matrix of a chloroplast, enclosed inside a double-membrane envelope in which the thylakoids are embedded. Site of the Calvin Cycle reactions.

Pigments

any molecule that absorbs certain wavelengths of visible light and reflects or transmits other wavelengths.

Wavelength

the distance between two successive crests or troughs in any regular wave, such as a light wave, sound wave, or wave in water.

Electromagnetic spectrum

the entire range of wavelengths of radiation extending from short wavelengths (high energy) to long wavelengths (low energy).

Visible light

the range of wavelengths of electromagnetic radiation that humans can see, from about 400 to 710 nanometers.

Photons

a discrete packet of light energy; a particle of light.

Chlorophyll

any of several closely related green pigments, found in chloroplasts, that absorb light during photosynthesis.

Carotenoids

any of a class of accessory pigments, found in chloroplasts, that absorb wavelengths of light not absorbed by chlorophyll; typically appear yellow, orange, or red. Includes carotenes and xanthophylls.

Action spectrum

the relative effectiveness of different wavelengths of light in driving a light-dependent process such as photosynthesis/ Usually depicted as a graph of some measure of the process, such as O2 production, verses wavelength.

Absorption spectrum

the amount of light of different wavelengths absorbed by a pigment. Usually depicted as a graph of light absorbed versus wavelength.

Fluorescence

the spontaneous emission of light from an excited electron in a pigment falling back to its normal (ground) state.

Photosystems

one of two types of units, consisting of a central reaction center surrounded by antenna pigments, that is responsible for the light-capturing reactions of photosynthesis.

Antenna pigments

part of a photosystem; chlorophyll molecules and accessory pigments organized and modified by proteins to capture light and direct energy to a central reaction during photosynthesis.

Reaction center

centrally locate component of a photosystem containing proteins and a pair of specialized chlorophyll molecules. It is surrounded by antenna pigments that transmit resonance energy to excite the reaction center pigments.

Resonance energy transfer

process of transferring energy from an excited donor pigment to an adjacent acceptor pigment, where another electron is excited in response.

Plastoquinone

a nonprotein electron carrier in the chloroplast electron transport chain. Receives excited electrons from photosystem 2 and photosystem 1 and passes them through an electron transport chain. Also transports protons from the stroma to the thylakoid lumen, generating a proton-motive force.

Photophosphorylation

production of ATP molecules by ATP synthase using the proton-motive force generated either (1) during photosynthesis, as light-excited electrons flow through an electron transport chain, or (2) in some bacteria or achaea, as rhodopsin-like molecules use absorbed light energy to pump protons across the plasma membranes to create a chemiosmotic gradient.

Oxygenic

referring to any process or reaction that produces oxygen.

Anoxygenic

referring to any process or reaction that does not produce oxygen.