AC-Ch. 1 Tree Biology Flashcards
Absorbing roots
Fine, fibrous roots to take up water and minerals. Most are within the top 12 inches of soil.
Abscission Zone
(Glossary)
Area at the base of a petiole, small branch, or flower where cellular breakdown leads to leaf, flower, or fruit drop
- To enable leaf drop.
- To protect the region of the stem from which the leaf has fallen against desiccation and pathogen entry.
(Chapter)
Abscission Zone’s two functions
Adventitious bud
Bud arising from a place other than a leave axil or shoot tip, usually as a result of hormonal triggers.
Aerial roots
Aboveground roots. Usually adventitious nature and sometimes having unique adaptive function.
Angiosperms
Plant seeds born in an ovary. Consist of two large groups: monocotyledons and Dicotyledons.
Anthocyanin
Red or purple pigment responsible for those colors and some parts of trees and other plants.
Antitranspirant
Substance applied to the foliage of plants to reduce water loss.
Apical or terminal bud
Bud at the tip of a twig or shoot
Apical dominance
Condition in which the terminal bud inhibits the growth and development of the lateral buds on the same stem formed during the same season
Apical meristem
Growing point at the tips of shoots and roots
Apoplasm
Free spaces in plant tissue. Includes cell walls and intracellular spaces.
Auxin
Plant hormones or substance that promotes or regulates the growth and development of plants. Produced at sites where cells are dividing, primarily in the shoot tips. Compounds may be synthetically produced
Axial transport
Movement of water, minerals, or Photosynthates longitudinally within a tree.
Axiliary bud
Bud in the axil of a leaf. Lateral bud.
Branch Bark Ridge
Raised strip of bark at the top of a branch union, where the growth and expansion of the trunk or parent stem and adjoining branch push the bark into a ridge.
Branch collar
Area were a branch joins another branch or trunk that is created by the overlapping vascular tissues from both the branch and the trunk. Typically enlarged at the base of the branch.
Bud
(1) Small lateral or terminal protuberance on the stem of a plant that may develop into a flower or shoot. (2) Undeveloped flower or shoot containing a meristematic growing point.
Buttress roots
Roots in the trunk base that help support the tree and equalize mechanical stress.
Cambium
Thin layer of meristematic cells that give rise to the phloem and to the xylem, increasing stem and root diameter.
Carbohydrate
Compound, combining carbon, hydrogen, and oxygen that is produced by plants as a result of photosynthesis.
Carotenoid
Yellow, orange, or red pigment responsible for those colors in some parts of trees and other plants.
Cellulose
Complex carbohydrate found in cellular walls of the majority on the plants and algae and certain fungi.
Chlorophyll
Green pigment of plants found in chloroplasts. Captures the energy of the sun and is essential and photosynthesis.
Chloroplast
Specialized organelle found in some cells. Site of photosynthesis.
Compartmentalization
Natural defense process in trees by which chemical and physical boundaries are created that act to limit the spread of disease and decay organisms.
Cork cambium
Meristematic tissue from which the Corky, protective outer layer of bark is formed.
Cuticle
Waxy layer outside of the epidermis of a leaf that reduces water loss and resists insect damage.
Cytokinin
Plant hormone involved in cell division, growth, shoot initiation, leaf expansion, and other physiological processes. Compounds producting similar activity may be synthetically produced.
Deciduous
Tree or other plant that sheds all of its foliage annually.
Decurrent
Rounded or spreading growth habit of the tree crown
Differentiation
Process in the development of cells in which they become specialized for various functions
Diffuse porous
Pattern of wood development in which the vessels and vessel sizes are distributed evenly throughout the annual ring
Dormant
In a period of dormancy
Earlywood/Latewood
Xylem cells produced earlier in a season are larger and more dense than those produced later. The contrast between them is why seasonal growth appears as rings
Ecology
Study of the relationships among organisms and other living and non living elements of their environment
Epicormic
Arising from a latent adventitious bud (growth point)
Evergreen
Tree or other plant that does not shed all of its foliage annually
Excurrent
Tree growth habit characterized by a central leader and a pyramidal crown
Fiber
Elongated tapering thick walled cell that provides strength to wood
Fronds
Large divided leaf structures found in palms and ferns
Geotropism
Plant growth produced as a response to the force of gravity (roots), or negative, as in opposite the direction of gravity (shoots)
Growth rings
Rings of xylem that are visible in a cross section of the stem, branches and roots of some trees. In temperate zones the rings typically represent one year of growth and are sometimes referred to as annual rings
Guard cells
Pair of specialized cells that regulate the opening and closing of a stomate due to a change in water pressure within cells
Gymnosperm
Plants with exposed seeds usually within cones
Heartwood
Wood that is altered from sapwood and provides chemical defense against decay-causing organisms and continues to provide structural strength to the trunk. Some trees do not have this
Included bark
Bark that becomes embedded in a crotch between branch and trunk or between codominant stems causes a weak structure
Inflorescence
Cluster of flowers
Internode
Region of the stem between two successive nodes
Lateral bud
Vegetative bud on the side of a stem
Lateral root
Root that arises by cell division in the pericycle of the parent root and then penetrates the cortex and epidermis
Leaf axil
Point of attachment of a leaf petiole to a stem
Lenticel
Small opening in the bark that permits the exchange of gases
Lignin
Organic substance that impregnates certain cell walls to thicken and strengthen the cell to reduce susceptibility to decay and pest damage
Meristem
Undifferentiated tissue in which active cell division takes place. Found in root tips, buds, cambium, cork cambium and latent buds
Mycorrhizae
Symbiotic association between certain fungi and the roots of a plant
Node
Slightly enlarged portion of a stem where leaves and buds arise
Organelle
A subcellular structure that has one or more specific jobs to perform in a cell, much like an organ does in a body.
Osmosis
Diffusion of water through a semipermeable membrane from a region of higher water potential to a region of lower water potential
Parenchyma cells
Thin walled living cells essential in photosynthesis, radial transport, energy storage and production of protective compounds
Periderm
The outer layers of tissue of woody roots and stems consisting of the cork cambium and the tissues produced by it
Petiole
Stalk or support axis of a leaf
Phloem
Plant vascular tissue that transports Photosynthates and growth regulators. Situated on the inside of bark just outside the cambium. Is bidirectional
Photosynthate
General term for the sugars and other carbohydrates produced during photosynthesis
Photosynthesis
Process in green plants by which light energy is used to form glucose from water and carbon
Phototropism
Influence of light on the direction of plant growth. Tendency of plants to grow toward light.
Plant growth regulator
Compound effective in small quantities that affects the growth and/or development of plants. May be naturally produced or synthetic
Plant hormone
Substance produced by a plant that in low concentrations affects physiological processes such as growth and development often at a distance from the substance point of origin
Primary growth
Root and stem growth in length. Occurs at the apical meristems and lateral meristems of all vascular plants
Propagation
Process of increasing plant numbers both sexually and asexually
Radial transport
Lateral movement of substances perpendicular to the longitudinal axis of the tree or stem
Ray
Parenchyma tissues that extend radially across the xylem and phloem of a tree and function in transport, storage, structural strength, and defense
Reaction zone
Natural boundry formed chemically within a tree to separate damaged wood from existing healthy wood. Important in the process of compartmentalization
Respiration
In plants process by which carbohydrates are converted into energy by using oxygen
Ring porous
Pattern of wood development in which the large diameter vessels are concentrated in the earlywood
Root crown
Area where the main roots join the plant stem usually at or near ground level. Root collar
Root initiation zone
Region at the base of a palm stem where lateral roots emerge
Root mat
Dense network of roots near the base of a palm
Sapwood
Outer wood (xylem) that is active in longitudinal transport of water and minerals.
Secondary growth
Increase in root and stem girth or diameter. Occurs at lateral meristems in some vascular plants such as dicots
Sieve cell
Long slender phloem cell in gymnosperms
Sieve tube elements
Specialized phloem cells involved in Photosynthate transport. Exist only in angiosperms
Sink
Plant part that uses or stores more energy than it produces.
Sinker roots
Downward growing roots that provide anchorage and take up water and minerals
Source
In physiology, a plant part that produces carbohydrates. Most green parts are indicitive of chlorophyll and photosynthesis, including mature leaves and green bark.
Stomata
Small pores between two guard cells on the undersides of leaves and other green plant parts through which gases are exchanged and water loss is regulated
Symbiosis
Association of two different types of living organisms that is not detrimental to either, is beneficial to one, and often to both.
Symplasm
Entire mass of protoplasm of all cells in a plant interconnected by plasmodesmata
Taproot
Central, vertical root growing directly below the main stem or trunk that may or may not persist into plant maturity
Temperate
Region lying between the tropics and the poles that has relatively moderate temperatures
Terminal bud
Bud at the tip of a twig or shoot.
Tracheid
Elongated, tapering xylem cell adapted for the support and transport of water and elements
Transpiration
Water vapor loss through the stomata of leaves
Tropism
Tendency of growth or variation of a plant in response to an external stimulus such as gravity or light
Twig
Small stem that provides a support structure for leaves, flowers, and fruit.
Vessels
End to end, tubelike, water conducting cells in the xylem of angiosperms
Xylem
Main water and mineral conducting tissue in trees and other plants. Provides structural support. Arises inward from the cambium and becomes wood after lignifying. Unidirectional up only
Absorption, conduction, anchorage, storage & hormone production
Name all the functions or the root system
Bark phloem cambium xylem
Name the major layers of a tree from outside to inside in order
