Chapter 5: Roots and Soils Flashcards
What do roots do?
anchor trees firmly in the soil, absorb water and minerals in solution, store and conduct
the part of an embryo in a seed that develops into a root
radicle
an immature sporophyte that develops from a zygote within an ovule or archegonium after fertilization
embryo
What are the regions of roots?
root cap, region of cell division, region of elongation, region of maturation/differentiation
a thimble-shaped mass of cells at the tip of a growing root; functions primarily in protection
root cap
area of actively dividing cells at an apical meristem
-cells are composed of an apical meristem in the center of the root tip
region of cell division
area near an apical meristem in which cells grow in length and width
region of elongation
area of maturing cells near an apical meristem
region of maturation/differentiation
area of cells in a root in which protuberances of epidermal cells can be found
root-hair zone
a colorless, starch-forming plastid found in roots and involved in gravity perception
amyloplast
the primary meristem that gives rise to the epidermis
protoderm
meristem that produces all the primary tissues other than the epidermis and stele
ground meristem
a primary meristematic tissue that differentiates into primary xylem and phloem
procambium
a tissue produced by the vascular cambium or the cork cambium
secondary tissue
a primary tissue composed mainly of parenchyma; the tissue usually extends between the epidermis and the vascular tissue
cortex
a single layer of cells surrounding the vascular tissue (stele) in roots and some stems; the cells have Casparian strips
endodermis
a band of suberin around the radial and transverse walls of an endodermal cell; blocks the passive flow of water and solutes into vascular tissue
Casparian strip
a thin-walled cell of an endodermis
passage cell
a core of tissues, including xylem and phloem, that lies to the inside of the endodermis
vascular cylinder
tissue sandwiched between the endodermis and phloem of a root; gives rise to lateral roots
pericycle
What are examples of plants with food-storage roots?
sweet potatoes, yams, water hemlocks, dandelions, salsify, carrots, beets, turnips, and radishes
What are some examples of plants with water-storage roots?
some members of the Pumpkin Family (Cucurbitaceae)
said of buds developing in internodes or on roots, or of roots developing along stems or on leaves
adventitious
spongy root extending above the surface of the water, produced by a plant growing in water; facilitate oxygen absorption
-ex: some swamp plants, such as the black mangrove and yellow water weed
pneumatophore
root formed above the ground
aerial root
What are some examples of plants with aerial roots?
velamen roots of orchids, prop roots of corn and banyan trees, adventitious roots of ivies
roots of parasitic plants; a protuberance of a fungal hypha or plant organ such as a root that functions as a penetrating and absorbing structure
haustorium (pl. haustoria)
an organism that lacks chlorophyll and obtains nutrients from dead or decaying organic matter
saprophyte
an organism that is attached to and grows on another organism without parasitizing it
epiphyte
a parasite that feeds upon another parasite
epiparasite
a plant that obtains its carbon from a fungus rather than from photosynthesis
myco-heterotroph
a symbiotic association between fungal hyphae and a plant root
-mutualistic association where both the fungus and the root benefit from it and are dependent upon the association for survival
-essential to the normal growth and development of forest tree and most herbaceous plants, and they facilitate the uptake of water and inorganic ions
mycorrhizae
a small swelling associated with nitrogen-fixing bacteria that invade the roots of leguminous plants and alders
root nodule
What do humans use roots for?
food, crops, dye, medicine/drugs, insecticide, hunting
-Rotenone is obtained from the barbasco plant and is used to poison fish but won’t poison anything else in the stream
-Nicotine from tobacco plants
-Drugs obtained from roots include aconite, ipecac, gentian, and reserpine
a substance consisting of a medium in which fine particles are permanently dispersed
colloid
What root system is root A?
fibrous root system in monocots
What root system is root B?
taproot system in dicots
What root is this a cross section of?
monocot root
What root is this a cross section of?
dicot root
root system where no one root is prominent over others, and it is great for stopping soil erosion
fibrous root system in monocots
root system with a primary root and lateral roots
taproot systems in dicots
