Term
| A vascular plant consists of a |
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Definition
| a root system and a shoot system. |
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Term
| Roots and shoots grow at their |
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Definition
| tips, which are called apices (singular, apex). |
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Term
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Definition
| anchors the plant and penetrates the soil, from which it absorbs water and minerals. These are often extensive, and growing roots can exert great force to move matter as they grow. |
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Definition
| consists of the stems and their leaves. |
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Term
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Definition
| later than shot system as an adaptation to living on land. Flowers, other reproductive organs and fruits and seeds are also formed on the shoot. |
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Term
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Definition
| scaffold for positioning the leaves, the principle sites for positioning the leaves. |
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Term
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Definition
| is a lateral shoot apex that allows the plant to branch or replace the main shoot if it is eaten by an herbivore. |
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Term
| A vegetative axillary bud |
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Definition
| has the capacity to replace the primary shoot. |
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Term
| Plant cell types can be distinguished by the |
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Definition
| size of their vacuoles, wether they are living or not at maturity, and by the thickness of their cellulose cell walls. |
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Term
| Cells that support the plant are |
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Definition
| more heavily reinforced cell walls with multiple layers of cellulose and other strengthening molecules such as lignin and pectin. |
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Term
| The three basic types of tissues in plants include: |
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Definition
| dermal, ground, and vascular tissue. |
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Term
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Definition
| primarily epidermis, is one cell layer thick in most plants and forms an outer protective covering for the plant. |
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Term
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Definition
| function in storage, photosynthesis, and secretion, in addition to forming fibers that support and protect plants. |
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Term
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Definition
| conducts fluids and dissolved substances throughout the plant body. |
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Term
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Definition
| are undifferentiated cells that can divide indefinitely and give rise to many types of differentiated cells. These are clusters of small cells with dense cytoplasm and large nuclei which act as stem cells do in animals. |
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Term
| The extension of both the root and shoot system occurs as a result of repeated cell divisions and subsequent elongation of the cells produced by |
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Definition
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Term
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Definition
| lateral meristems produce an increase in root and shoot diameter. |
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Term
| Apical meristems are located |
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Definition
| at the tips of stems and roots. |
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Term
| The tissues derived from apical meristems are called |
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Definition
|
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Term
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Definition
| are tissues that make up the plant body |
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Term
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Definition
| the extension of the root and stems |
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Term
| The three primary meristems |
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Definition
| protoderm, precambium and ground meristem |
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Term
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Definition
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Term
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Definition
| differentiates further into ground tissue |
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Term
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Definition
| produces primary vascular tissues |
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Term
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Definition
| arise in stem internodes (spaces between leaf attachments), adding to the internode lengths. |
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Term
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Definition
| produce secondary growth. This is the peripheral cylinders of meristematic tissue within the stems and roots that increase the diameter of gymnosperms and most angiosperms. |
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Term
| In woody plants there are two lateral meristems. |
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Definition
| Cork cambium and vascular cambium. The Vascular meristem is just beneath the cork cambium. |
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Term
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Definition
| is a lateral meristem that contributes to the outer bark of a tree |
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Term
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Definition
| a lateral meristem that produces secondary vascular tissue. It forms between the xylem and phloem in vascular bundles, adding secondary vascular tissues to both sides. Xylem is added to the inside of the vascular cambium and phloem is on the outside. |
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Term
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Definition
| formed from lateral meristems in trees and shrubs |
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Term
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Definition
| the part of a plant that consists of secondary tissues from lateral meristem tissues; the older trunk, branches and roots of woody plants. |
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Term
| The epidermis is formed from the |
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Definition
|
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Term
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Definition
| is one cell layer thick in most plants and forms the outer protective covering of the plant. This is a dermal tissue. |
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Term
| In young, exposed parts of the plant, the epidermis is covered with a |
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Definition
| fatty cutin layer constituting the cuticle |
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Term
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Definition
| a waxy or fatty noncellular layer (formed of cutin) on the outer wall of the epidermis. Helps to limit water loss and protects from UV damage. |
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Term
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Definition
| are paired, sausage shaped cells flanking a stoma. Contains chloroplasts. |
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Term
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Definition
| a mouth-shaped epidermal opening. Water vapor and carbon dioxide is let in and oxygen is released. |
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Term
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Definition
| encodes a membrane-bound receptor that is part of a signaling pathway controlling asymmetrical cell division. |
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Term
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Definition
| are cellular or multicellular hairlike outgrowths of the epidermis. They occur frequently on stems, leaves, and reproductive organs. These reduce evaporation by covering stomatal openings. They also protect leaves from UV radiation and high-intensity lights. Some are glandular, secreting sticky or toxic substances. |
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Term
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Definition
| are tubular extensions of individual epidermal cells, and occur in a zone just behind the tips of young, growing roots. No cell wall isolates the hair from the rest of the cell. Increases the root's surface area and efficiency of absorption. |
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Term
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Definition
| , the extent of the root hair zone remains roughly constant as root hairs at the older end slough off while new ones are produced at the apex. |
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Term
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Definition
| of thin-walled parenchyma cells that function in storage, secretion, and photosynthesis. Other ground tissues, composed of collenchyma cells and sclerenchyma cells provide support and protection. |
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Term
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Definition
| are most common type of plant cell. They have large vacuoles, thin walls, and are initially (but briefly) more or less spherical. These cells, which have living protoplasts, push ip against each other shortly after they are produced, however, and assume other shapes and often end up with 11 to 17 sides. They may live for many years and function in storage of food and water, photosynthesis and secretion. |
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Term
| Some parenchyma cells contain |
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Definition
| chloroplasts, especially in leaves and the outer parts of herbaceous stems. |
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Term
| Collenchyma cells, like parenchyma cells, |
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Definition
| have living protoplasts, lack cell walls and may live for many years. These cells are usually a little longer than wide, have walls that vary in thickness. These flexible cells provide support for plant organs, allowing them to bend without breaking. They often form strands or continuous cylinders beneath the epidermis of cells or leaf stalks and along veins in leaves. |
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Term
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Definition
| have thick walls. They are usually dead at maturity. Their secondary cell walls often contain lignin. Occurs in two types; fivers and sclereids. |
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Term
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Definition
| is a highly branched polymer that makes cell walls more rigid. |
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Term
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Definition
| long and slender cells that are usually grouped together in strands. |
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Term
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Definition
| variable in shape but often branched. May occur singly or in groups; aren't elongated, but may have different forms, including that of a star. |
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Term
| Vascular tissue includes two types of conducting tissues; |
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Definition
|
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Term
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Definition
| conducts water and dissolved minerals. Contains a combination of vessels. Also supports plant body. Includes fibers and parenchyma cells. |
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Term
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Definition
| conducts a solution of carbohydrates (mainly sucrose). Also transports hormones, amino acids, and other substances needed for cell growth. Located on the outer part of roots and stems. Two kinds of elongated cells; sieve cells and sieve-tube mebers. |
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Term
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Definition
| continuous tubes formed from dead, hollow, cylindrical cells arranged end-to-end. |
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Term
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Definition
| dead cells that taper at the ends and overlap one another. Contains pits |
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Term
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Definition
| The loss of water vapor by plant parts; mainly in stomata |
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Term
| Vessel members tend to be |
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Definition
| shorter and wider than tracheids. |
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Term
| Both vessel memvers and tracheids have |
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Definition
| thick, lignified secondary walls and no living protoplasts at maturity. |
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Term
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Definition
| small areas where no secondary wall material has been deposited. The primary wall is present but it is water permeable. There is a continuous flow of water from tracheid to tracheid |
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Term
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Definition
| less specialized than sieve-tube members, and the pores in all of their sieve areas are about the same diameter. |
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Term
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Definition
| Stacked up end to end in the phloem forming longitudinal series called sieve tubes. More efficient than sieve cells. |
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Term
| Each sieve tube member is associated with an adjacent, parenchyma cell known as a companion cells. The companion cells |
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Definition
| carry our some of the metabolic functions needed to maintain the associated sieve-tube member, because the sieve tube member lacks a nucleus. |
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Term
| There are 4 regions in developing roots |
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Definition
| the root cap, the zone of cell division, the zone of elongation and the zone of maturation |
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Term
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Definition
| is composed of two types of cells, inner columella cells and the outer lateral root cap cells. Protects the delicate tissues behind it as it moves through the soil. |
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Term
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Definition
| amyloplasts (plastids with starch grains) that collect on the sideds of cells facing the pull of gravity. |
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Term
| The zone of cell division |
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Definition
| most of the activity takes place toward the edges of the meristem, which is located in the center of the root tip and protected by the root cap, where the cells divide every 12 to 37 hours. |
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Term
| A group of cells in the center of the root apical meristem |
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Definition
| called the quiescent center, divides only very infrequently. |
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Term
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Definition
| is where roots lengthen because the cells produced by the primary meristems elongate. The small vacuoles merge and grow till they occupy 90% or more of the volume of each cell. Cells don't increase past the zone of elongation. |
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Term
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Definition
| The cells that have elongated in the zone of elongation become differentiated into specific cell types |
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Term
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Definition
| may be many cell layers wide and functions in food storage |
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Term
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Definition
| surround each adjacent endodermal cell wall perpendicular to the root's surface. Blocks transport between cells. |
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Term
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Definition
| The center vascular system of stems and roots |
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Term
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Definition
| one or more cell layers that surrounds the vascular tissues of the root, bounded externally by the endodermis and internally by the phloem. |
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Term
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Definition
| any root that arises along a stem or in some place other than the root |
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Term
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Definition
| These so-called prop roots grow down to the ground and brace the plants against wind |
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Term
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Definition
| which are attached to tree branches and grow unconnected to the ground (but are not parasites), have roots that extend into the air. Some aerial roots have an epidermis that is several cell layers thick, an adaptation to reduce water loss. These aerial roots may also be green and photosynthetic |
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Term
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Definition
| Some plants that grow in swamps and other wet places may produce spongy outgrowths called pneumatophores from their underwater roots. The pneumatophores commonly extend several centimeters above water, facilitating oxygen uptake in the roots beneath |
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Term
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Definition
| penetrate the host plants around which they are twined. The haustoria establish contact with the conducting tissues of the host and effectively parasitize their host. Dodder not only weakens plants but can also spread disease when it grows and attaches to several plants. |
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Term
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Definition
| produce extra parenchyma cells that store large quantities of carbohydrates. Carrots, beets, parsnips, radishes, and turnips have combinations of stem and root tissues that also function in food storage. Cross sections of these roots reveal multiple rings of secondary growth. |
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Term
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Definition
| arid regions, may produce water storage roots weighing 50 kg or more |
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Term
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Definition
| produce huge buttress roots toward the base of the trunk, which provide considerable stability |
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Term
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Definition
| contract by spiraling to pull the plant a little deeper into the soil each year, until they reach an area of relatively stable temperature. |
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Term
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Definition
| Single large root with small branch roots |
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Term
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Definition
| many small roots of similar diameter |
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Term
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Definition
| point of attachment of leaf to stem |
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Term
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Definition
| area of stem between two nodes |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| angle between petiole/blade and stem |
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Term
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Definition
| develops into branches with leaves or may form flowers |
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Term
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Definition
| extends the shoot system during the growing season |
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Term
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Definition
| Cork cambium produces unsuberized cells that permit gas exchange to continue |
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Term
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Definition
| horizontal stems with long internodes that grow along the surface of the ground |
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Term
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Definition
| Leaf with one vein branching from the vascular cylinder of the stem and not extending the full length of the leaf |
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Term
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Definition
Several to many veins
(most plants) |
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Term
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Definition
Most eudicot leaves have a flattened petiole
Slender stalk called petiole
Leaf flattening increases photosynthetic surface
Flattening of the leaf blade reflects a shift from radial symmetry to dorsal–ventral (top–bottom) symmetry |
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Term
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Definition
Outgrowths at base of petiole
May be leaf-forming or modified as spines |
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Term
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Definition
Vascular bundles in leaves
Main veins are parallel in most monocot leaves
Veins of eudicots form an often intricate network |
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Term
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Definition
contain undivided blades
May have teeth, indentations, or lobes |
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Term
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Definition
| blades that are divided into leaflets |
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Term
| Most eudicot leaves have 2 types of mesophyll |
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Definition
| Palisade mesophyll and Spongy mesophyll |
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Term
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Definition
| loosely arranged cells with many air spaces in between |
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Term
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Definition
| usually two rows of tightly packed chlorenchyma cells |
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Term
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Definition
| mesophyll is usually not differentiated into palisade/spongy layers |
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Term
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Definition
| surround true flowers and behave as showy petals |
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Term
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Definition
| reduce water loss and may deter predators |
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Term
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Definition
| plantlets capable of growing independently into full-sized plant |
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Term
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Definition
| succulent, cone-shaped leaves that allow photosynthesis underground |
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Term
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Definition
| larger in surface area but with less mesophyll than sun-lit leaves |
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Term
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Definition
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Term
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Definition
| water-selective pores in plasma membrane that increase the rate of osmosis because they allow bulk flow |
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Term
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Definition
If a single plant cell is placed into water
Water moves into cell by osmosis
Cell expands and becomes turgid
If cell placed in high concentration of sucrose
Water leaves cell
Cell shrinks – plasmolysis |
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Term
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Definition
movement through the cell walls and the space between cells
Avoids membrane transport |
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Term
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Definition
| cytoplasm continuum between cells connected by plasmodesmata |
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Term
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Definition
membrane transport between cells and across the membranes of vacuoles within cells
Permits the greatest control |
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Term
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Definition
occurs at the source
Carbohydrates enter the sieve tubes in the smallest veins at the source
Sieve cells must be alive to use active transport to load sucrose
Water flows into sieve tubes by osmosis
Turgor pressure drives fluid throughout plant
At sink, sucrose actively removed and water follows by osmosis
Water may be recirculated in xylem or lost |
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Term
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Definition
is a model describing the movement of carbohydrates in phloem
Dissolved carbohydrates flow from a source and are released at a sink
Sources include photosynthetic tissues
Food-storage tissue can be sources or sinks
Sinks include growing root and stem tips as well as developing fruits |
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Term
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Definition
| Plants that can tolerate soils with high salt concentrations |
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Term
| Over 90% of the water taken in by the plant’s roots is ultimately |
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Definition
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Term
|
Definition
An air bubble can break the tensile strength of a water column
A gas-filled bubble can expand and block the tracheid or vessel |
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Term
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Definition
Highly weathered outer layer of the Earth’s crust
Mixture of sand, rocks, clay, silt, humus, and mineral and organic matter
The Earth’s crust includes about 92 naturally occurring elements
Most are found in the form of inorganic compounds called minerals
Also full of microorganisms |
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Term
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Definition
Most roots are found in topsoil
Mixture of mineral particles of varying sizes, living organisms, and humus
Characterized by their relative amounts of sand, silt, and clay
Soil composition determines the degree of water and nutrient binding to soil particles |
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Term
| Only minerals dissolved in water in spaces among soil particles are |
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Definition
| available for uptake by roots |
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Term
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Definition
About half of the soil volume is occupied by pores
May be filled with air or water |
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Term
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Definition
| soil’s water-holding capacity and nutrient content are adversely affected |
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Term
| Measures to prevent erosion |
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Definition
Intercropping
Conservation tillage
No-till |
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Term
| Measures to prevent fertilizer runoff |
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Definition
Site-specific farming
Integrated nutrient management |
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Term
| Acidic soils release minerals, such as aluminum |
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Definition
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Term
| Saline soils alter water potential, leading to a |
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Definition
| loss of water and turgor in plants |
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Term
Macronutrients -used in relatively large amounts
- needed in plants |
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Definition
| Nine = C, O, H, N, K, Ca, Mg, P, and S |
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Term
| Micronutrients – used in minute amounts - needed in plants |
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Definition
| Seven = Cl, Fe, Mn, Zn, B, Cu, and Mo |
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Term
| Photosynthesis is major source of |
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Definition
| plant nutrition via the fixation of _CO_2_ into sugar using solar energy |
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Term
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Definition
plant roots are suspended in aerated water containing nutrients
Plant seedling is first grown in a complete nutrient solution
Seedling is then transplanted to a solution lacking one suspected essential nutrient
Growth of the seedling is monitored for presence of abnormal symptoms |
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Term
Plants need ammonia _(NH_3_) or nitrate _(NO_3_−_) to ______
However, they lack the biochemical pathways necessary to convert _____ |
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Definition
to build amino acids
_N_2_ to _NH_3_ |
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Term
| Rhizobium bacteria require oxygen and carbohydrates to support their energetically expensive lifestyle as nitrogen fixers |
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Definition
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Term
| Symbiotic associations with mycorrhizal fungi are found in about |
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Definition
90% of vascular plants
Substantially expand the surface area available for nutrient uptake
Enhance uptake of phosphorus and micronutrients |
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Term
|
Definition
Often grow in acidic soils that lack nitrogen
Trap and digest small animals, primarily insects, to extract additional nutrients
Have modified leaves adapted for luring and trapping prey
Prey is digested with enzymes secreted from specialized glands |
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Term
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Definition
| Have pitcher-shaped leaves with cavity filled with digestive fluid |
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Term
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Definition
| When hairs are touched, the two halves of the leaf snap together |
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Term
|
Definition
| Glandular trichomes secrete both sticky mucilage and digestive enzymes |
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Term
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Definition
| Uses trigger hairs and snaps to capture and digest small aquatic animals |
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Term
| The snap-trap mechanism was acquired by a common ancestor of |
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Definition
| the Venus flytrap and the aquatic waterwheel |
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Term
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Definition
(nonphotosynthetic)
Wraps around its host
Relies on host for its nutritional needs |
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Term
|
Definition
(nonphotosynthetic)
Hooks into host trees through mycorrhizae |
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Term
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Definition
_CO_2_ into sugar
Ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) catalyzes the first step
Can bind _CO_2_ or _O_2_
If _CO_2_ binds, a 3-C sugar is made, that can be used to make glucose and sucrose
If _O_2_ binds, photorespiration occurs
Neither nutrient nor energy storage |
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Term
| _C_3_ photosynthesis occurs in |
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Definition
|
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Term
| _C_4_ photosynthesis uses |
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Definition
an extra pathway to shuttle carbon deep within the leaf
This reduces photorespiration by limiting the Calvin cycle to cells surrounding the vascular tissue where _O_2_ levels are low |
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Term
| In _C_3_ plants, as _CO_2_ increases |
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Definition
| the Calvin cycle becomes more efficient |
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Term
| As _CO_2_ levels increase, |
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Definition
| relatively less nitrogen and other macronutrients are found in leaves |
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Term
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Definition
| Use of plants to concentrate or breakdown pollutants |
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Term
|
Definition
| contaminant is taken up from soil and broken down |
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Term
|
Definition
| contaminant is taken up from soil and released through stomata |
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Term
|
Definition
contaminant is taken up from soil and concentrated in shoots
These are later harvested |
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Term
|
Definition
May be removed from the soil by poplar trees
Degraded into _CO_2_ and chlorine
A fraction moves rapidly through the xylem and is released through stomata |
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Term
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Definition
May be removed from soil and degraded by poplar and bean plants
But at high concentrations, it is toxic to these plants |
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Term
| Heavy metals, including arsenic, cadmium, and lead, are |
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Definition
| toxic to animals in even small quantities |
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Term
| 400 plant species have the ability to |
|
Definition
| hyperaccumulate toxic metals from soi; |
|
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Term
|
Definition
| One of the greatest problems with nonnative invasive species, such as the emerald ash borer, is the lack of natural predators in the new environment |
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Term
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Definition
First-line defense of all plants
Epidermal cells throughout the plant secrete wax to protect plant surfaces from water loss and attack
Above-ground parts also covered with cutin
Suberin is found in cell walls of subterranean plant organs
Silica inclusions, trichomes, bark, and even thorns can also offer protection |
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Term
|
Definition
|
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Term
| Phases of fungal invasion |
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Definition
Windblown spore lands on leaves
Spore germinates and forms adhesion pad
Hyphae grow through cell walls and press against cell membrane
Hyphae differentiate into haustoria |
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Term
| Fungi and bacteria can also be beneficial to plants |
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Definition
Mycorrhizal fungi
Nitrogen-fixing bacteria like Rhizobium
Plant growth-promoting rhizobia (PGPR)
Bacteria provide substances that support plant growth
Can also limit the growth of pathogenic soil bacteria |
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Term
| Many plants produce toxins that |
|
Definition
| kill herbivores, make them ill |
|
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Term
| Metabolic pathways needed to |
|
Definition
| sustain life are modified |
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Term
| Plants protect themselves from toxins in two main ways |
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Definition
Sequester a toxin in a membrane-bound structure
Produce a compound that is not toxic until it is metabolized by attacking animal
Cyanogenic glycosides break down into cyanide (HCN) when ingested |
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Term
|
Definition
Secrete chemicals to block seed germination or inhibit growth of nearby plants
This strategy minimizes competition for resources |
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Term
|
Definition
Ricin is an alkaloid produced by the castor bean plant (Ricinus communis)
It is six times more lethal than cyanide and twice as lethal as cobra venom
A single seed can kill a small child
It functions as a ribosome-binding protein that inhibits translation |
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Term
| Many secondary metabolites have |
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Definition
|
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Term
| Phytoestrogens of soy plants |
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Definition
Appear to lower the rate of prostate cancer in Asian males
However, questions have been raised about their effect on unborn babies
Also on babies consuming soy-based formula |
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Term
| Taxol of Pacific yew trees |
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Definition
| Fights cancers, especially breast cancer |
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Term
| Quinine of Cinchona trees |
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Definition
Effective against malaria, which is caused by four species of Plasmodium
Blocks DNA replication
Also leads to build-up of toxic hemes that poison the parasite |
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Term
| Complex coevolution of plants and animals has resulted in |
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Definition
|
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Term
|
Definition
Small armies of ants protect Acacia trees from harmful herbivores
Plant provides ants with food and shelter |
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Term
|
Definition
Wounded leaves produce an 18-amino acid peptide called systemin
Systemin moves throughout the plant in the phloem
Cells with receptors produce jasmonic acid
Jasmonic acid turns on genes for proteinase inhibitor |
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Term
| H. H. Flor’s gene-for-gene hypothesis |
|
Definition
Plants have a plant resistance gene (R); pathogens have an avirulence gene (avr)
It is the recognition of the gene products (i.e. proteins) that is critical
If binding occurs, plant can mount defenses that keep pathogen avirulent
If no binding occurs, the plant succumbs to disease |
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Term
|
Definition
Recognition of the pathogen by the R gene product leads to hypersensitive response
Leads to a very rapid cell death around the site of attack
Also to longer term, whole plant resistance |
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Term
|
Definition
Rapid cell death due to hypersensitive response
Seals off the wounded tissue to prevent the pathogen or pest from moving into rest of the plant
Hydrogen peroxide and nitric oxide produced
May signal cascade of chemical events resulting in localized host cell death
Phytoalexins – antimicrobial chemical defense agents |
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Term
| Systemic Acquired Resistance (SAR) |
|
Definition
systemic response by plants
Several pathways lead to broad-ranging resistance that lasts for a period of days
Long-distance inducer is likely salicylic acid
At the cellular level, jasmonic acid is involved in SAR signaling
SAR allows the plant to respond more quickly to a second attack |
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