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Topic: Thallus tissue


  
  Thallus (tissue) - Wikipedia, the free encyclopedia
Thallus, from Latinized Greek θαλλος (thallos), meaning a green shoot or twig, is an undifferentiated vegetative tissue of some non-mobile organisms, which were previously known as the thallophytes.
An organism or structure resembling a thallus is called thalloid, thallodal, thalliform, thalline, or thallose.
A kelp, for example, may have its thallus divided into three regions.
en.wikipedia.org /wiki/Thallus_(tissue)   (215 words)

  
 Plants - LoveToKnow 1911
At the apex of a root, covering and protecting th~ delicate tissue of the growing point, is a special root-cap consistinf of a number of layers of tissue whose cells break down into mucilagi towards the outer surface, thus facilitating the passage of the ape~ as it is pushed between the particles of soil.
The main assimilating tissue, on the other hand, is under the upper epidermis, where it is well illuminated, and consists of oblong cells densely packed with chloroplasts and with their long axes perpendicular to the surface (palisade tissue).
The young tissue of the stelar cylinder, in the case of the modified siphonostele characteristic of the dicotyledonous stem, differs from the adjoining pith and cortex in its narrow elongated cells, a difference produced by the stopping of transverse and the increased frequency of longitudinal divisions.
www.1911encyclopedia.org /Plants   (19071 words)

  
 Encyclopedia :: encyclopedia : Biological tissue   (Site not responding. Last check: 2007-10-31)
The study of tissues is known as histology, or, in connection with disease, histopathology.
The classical tools for studying the tissues are the wax block, the tissue stain, and the optical microscope, though developments in electron microscopy, immunofluorescence, and frozen sections have all added to the sum of knowledge in the last couple of decades.
Vascular tissue - The primary components of vascular tissue are the xylem and phloem.
www.hallencyclopedia.com /Biological_tissue   (326 words)

  
 Australian Biological Resources Study - Flora of Australia - Glossary - Lichens   (Site not responding. Last check: 2007-10-31)
anticlinal: of the orientation of hyphae in a tissue, perpendicular to the surface.
exciple: of an apothecium, tissue or tissues characteristic of the margins adjacent to the hymenium and hypothecium.
Thalline exciple (excipulum thallinum) - tissue at the margin of an apothecium external to proper exciple and having a structure similar to that of the vegetative thallus with photobiont cells included in it.
www.deh.gov.au /biodiversity/abrs/online-resources/glossaries/lichen/index.html   (3828 words)

  
 ANATOMY OF - Online Information article about ANATOMY OF
Special tissues (stereom) may be developed for this purpose in the cortex, or in immediate connexion with the conducting system, according to the varying needs of the particular type of plant-body.
At the apex of a root, covering and protecting the delicate tissue of the growing point, is a special root-cap consisting of a number of layers of tissue whose cells break down into mucilage towards the outer surface, thus facilitating the passage of the apex as it is pushed between the particles of soil.
These successive new tissues, appearing in the centre of the stele, as the stem of a higher fern is traced upwards from its first formed parts, are all in continuity with the respective corresponding external tissues at the point of origin of each leaf trace (see below).
encyclopedia.jrank.org /ALM_ANC/ANATOMY_OF.html   (10705 words)

  
 Mycology - Lichens - Lichen Biology
The thallus is highly differentiated, with the lower surface being an absorptive tissue and the photobionts being held in a manner that maximises photosynthesis.
The thallus may be covered by or enmeshed in fungal secondary metabolites.
The thallus is commonly interleaved by hyphal layers.
bugs.bio.usyd.edu.au /Mycology/Plant_Interactions/Lichen/lichenBiology.shtml   (2001 words)

  
 Chloroplast - algal-like
The sporophyte is protected in its early stages by gametophytic tissue forming an involucre.
As the sporophyte develops the involucre is broken and remains as a cylinder that surrounds the base of the sporophyte.
The sporophyte is comprised of a bulbous foot embedded in the gametophyte and an elongated cylindrical spore-bearing region.
vis-pc.plantbio.ohiou.edu /moss/Tomescu.htm   (748 words)

  
 Thallus - Wikipedia, the free encyclopedia
Thallus (tissue), an undifferentiated vegetative tissue (without specialization of function) of some non-mobile organisms, which were previously known as the thallophytes.
Thallus (historian), a chronologer/historian occasionally mentioned in the works of early Christian writers.
This is a disambiguation page: a list of articles associated with the same title.
en.wikipedia.org /wiki/Thallus   (111 words)

  
 Anthocerophyta Description
In the epiphyllous Dendroceros, the thallus is ribbon-shaped with an enlarged central midrib and thin lateral wings.
Rhizoids are unicellular and smooth, while the thickened thallus lacks internal differentiation, except for the occurrence of rather extensive mucilage canals in some species.
An assimilative (photosynthetic) layer underlies the epidermis and the sporogenous tissue is situated between this layer and the columella.
www.science.siu.edu /landplants/Anthocerophyta/HornwortDesc.html   (479 words)

  
 Graphidaceae of Central French Guiana
Two important distinctions are made in the keys regarding this layer of tissue: degree of carbonization and presence or absence of striation.
This tissue is referred to here as the thalline veil and can be comprised of anything from a powdery or mealy thin covering of hyphae, to a thick, continuous, cartilaginous corticate layer, with or without algae and/or crystals.
Thallus characters are not very reliable, as colors can be variable depending on age and condition of thallus, whether or not it has been grazed, etc. One character that is reliable however, is the presence of a layered, clear prosoplectenchymatous cortex.
www.nybg.org /bsci/french_guiana/graphidaceae.html   (1935 words)

  
 Key to genera of foliicolous lichens
Thallus ecorticate or cortex cartilaginous or formed by an irregular layer of rounded cells..........
Thallus farinose-granulose, composed of goniocysts; apothecia pale yellow to orange, slightly translucent, rarely brown; asci with I+ pale, conical to broadly cylindrical axial mass; conidiomata of various types, producing filiform to acicular conidia..........
Thallus smooth or verrucose-rugose, not composed of goniocysts; apothecia light to dark brown or fl, opaque; asci of the Byssoloma type, with I+ pale bluish tholus containing a darker blue tubular structure; conidiomata pycnidia, producing fusiform to ellipsoid conidia..........
www.uni-bayreuth.de /departments/planta2/ass/robert/lichens/key_genera.html   (3012 words)

  
 Thallus organization in coralline algae
Note that the thallus is constructed from the aggregation filaments, and is therefore pseudoparenchymatous.
Most coralline algae have an internal anatomy of the thallus that is based on the aggregation of branching filaments, each of which is formed through the action of its own single meristematic cell.
Since their anatomy is based on the elaboration of filaments, true tissues do not occur in coralline algae, and it is therefore incorrect to use the term ‘tissue’ do describe regions within the thallus.
www.botany.uwc.ac.za /clines/organiz.htm   (488 words)

  
 FUNGI (p1. of Lat. fun... - Online Information article about FUNGI (p1. of Lat. fun...
Latex-tubes abound in the tissues of Lactarius, Stereum, Mycena, Fistulina, filled with white or coloured milky fluids, and Istvanffvi has shown that similar tubes with fluid or oily contents are widely spread in other Hymenomycetes.
In these cases the compound sporophore is often termed the hymenophore, and its various parts demand special names (pileus, stipes, gills, pores, andc.) to denote peculiarities of distribution of the hymenium over the surface.
Other series of modifications arise in which the tissues corresponding to the stroma invest the sporogenous hyphal ends, and thus enclose the spores, asci, basidia, andc., in a cavity.
encyclopedia.jrank.org /FRA_GAE/FUNGI_p1_of_Lat_fungus_a_mushro.html   (6107 words)

  
 Algae - Wikipedia, the free encyclopedia
Algae are usually found in damp places or bodies of water and thus are common in terrestrial as well as aquatic environments.
However, terrestrial algae are usually rather inconspicuous and far more common in moist, tropical regions than dry ones, because algae lack vascular tissues and other adaptations to live on land.
These are the brown algae — some of which may reach 70 m in length (kelps) — the red algae, and the green algae.
en.wikipedia.org /wiki/Alga   (2928 words)

  
 Bryophyta, Laboratory Notes for BIO 1003 and 3001   (Site not responding. Last check: 2007-10-31)
The haploid thallus (n) grows flat on moist ground, and it is many-cells thick.
Extending into the ground under the thallus are tapering chains of cells called scales, which anchor the plant, and twisting cells called rhizoids, which absorb water.
The diploid sporophyte plant (2n) occupies a former archegonium and is dependent on the haploid tissue of the archegoniophore for nutrients and water.
darwin.baruch.cuny.edu /bio1003/bryophyta.html   (671 words)

  
 Cystoseira morphology
Much of Cystoseira osmundacea's morphology is visible to the naked eye, the complex thallus construction being differentiated into floats, blades, a stipe, and a holdfast.
Cystoseira osmundacea's thallus, or body, construction is parenchymatous, meaning that the cells divide such that they form a fleshy sheet of tissue.
Blades tend to have relatively more peripheral and medulla tissue, and they tend to have higher concentrations of chloroplasts and mitochondria, indicating relatively high levels of photosynthesis and respiration.
www.mbari.org /staff/conn/botany/browns/Cystoseira/morphology.htm   (960 words)

  
 Meristem growth dynamics and branching patterns in the Cladoniaceae -- Hammer 87 (1): 33 -- American Journal of Botany
the fungal meristem tissue at the apex of the podetium.
The largest portion of meristem tissue is at the apex (near the figure number) and the smallest is at the bottom of the figure.
rapid elongation of the lichenized tissue distal to the meristem
www.amjbot.org /cgi/content/full/87/1/33   (4623 words)

  
 FILL IN QUESTIONS (1 pt each)
29_______________________ a filament of the thallus of a fungus.
From the outside of the plant to its center and in their correct sequence, list the tissues that would be present at the end of the first year of secondary growth.
Next to each tissue, indicate all the cell types that would be found in each tissue Make sure your list includes cells types which are found in primary as well as in secondary tissues.
www.humboldt.edu /~dll2/bot105/exams/LECT1-95.htm   (825 words)

  
 Dr.James Moore
Silica is one of the most important components of the connective tissue: cartilage, tendons, and some elements of the arterial walls, skin, hair and nails.
Moreover, since silica is an element of structure, tissue depends on it for its elasticity.
It is known that adrenalin is the hormone that frees fatty acids of the adipose tissues.
www.herbalconsults.com /research1.html   (5947 words)

  
 Morphology and anatomy of the Caliciales
The thallus is rather thin and consists of small, ecorticate or pseudocorticate granules consisting of algae surrounded by hyphae.
The thallus is rather thick, and the algae and hyphae are covered by a thin cortex.
The hyphae of the stalk are dark brown and irregularly arranged in Calicium and Microcalicium; and medium or pale brown and periclinally arranged in Chaenotheca and Sclerophora.
thavibu.com /caliciales/morpholo.htm   (621 words)

  
 Sarcographa sp. Harris 33372
Thallus greenish to yellowish, thickly cartilaginous and unevenly developed, tuberculate, cracked and appearing aereolate; thin prosoplectenchymatous layer smooth and slightly shiny; K+ red, P-; lirellae crowded and pressed together in dense raised creamy to whitish stromata; stromata weakly raised, with margins defined by outer labia of lirellae, not at all exceeding margins.
Stromatic tissue of moderately densely woven colorless hyphae with many large crystalline inclusions inspersed throughout upper layers of bark.
Disks grayish, narrowly exposed (0.03-.08mm) lightly white pruinose, bordered by raised white crumbling margins often and split from surrounding stromatic tissue and thallus by one deep lateral fissure.
www.nybg.org /bsci/french_guiana/H33372.html   (155 words)

  
 Nitrogen and seaweed thallus colour
This is because the pigment protein phycoerythrin is largely responsible for determining the red colour of the thalli, and the concentrations of this pigment change according to nitrogen content, causing lightening or darkening of seaweed’s thallus.
He found a relationship between thallus colour and tissue nitrogen, as well as a transition between green-yellows and yellow-browns which occurs between 0.8 - 1.6 % (Figure 1) of the total nitrogen with the green yellow colour indicating nitrogen starved material and the yellow browns indicating nitrogen rich material.
lactuca is plotted against tissue colour from thalli obtained from 2 abalone farms in a number of different effluent treatments, a broad relationship between thallus colour and nitrogen content is clear to see (Figure 2).
www.botany.uwc.ac.za /pssa/articles/students/no58-randersson.htm   (766 words)

  
 Lecture 16 Outline
A period of morphogenesis and histogenesis in which the major organ and tissue systems of the plant are established.
Accumulation cell type specific molecular markers indicated that tissue (cell) differentiation proceeded beyond that normally seen at the stage of morphogenesis at which the embryo was blocked.
The role for these proteins in desiccation tolerance is supported by their induction by drought stress in vegetative tissues and during desiccation of the resurrection plant, one of the few plants that can tolerate desiccation of postembryonic tissues.
www.public.iastate.edu /~bot.512/lectures/embryo.htm   (3412 words)

  
 Mosses   (Site not responding. Last check: 2007-10-31)
The thallus is anchored to the substrate by rhizoids arising from the lower surface.
A thin cross section of the thallus should show that the cells in different parts of the thallus are specialized for different functions.
As the thallus elongates near the tips, branching repeatedly, the older portion dies and the many ends become independent plants.
koning.ecsu.ctstateu.edu /Plant_Biology/Mosses.html   (2369 words)

  
 Liverworts, Hornworts, and Mosses   (Site not responding. Last check: 2007-10-31)
Gemmae develop from surface cells and are borne upon the thallus surface sometimes in clusters upon the surface or at the apex, or on margins of enations.
The thallus has a dorsal central furrow with an inverted Y-shape which functions as a capillary channel for the capture and uptake of water, and through which sperm swim to reach the archegonia embedded in the thallus at the base of the furrow (Fig.
On the ventral surface of the thallus, rhizoids are aggregated into a central strip and enclosed by overlapping, scaly outgrowths of the thallus parallel to the strip of rhizoids (Fig.
www.bio.ilstu.edu /armstrong/syllabi/222book/chapt6.htm   (8918 words)

  
 Bryophytes: Liverworts   (Site not responding. Last check: 2007-10-31)
The gametophyte plant body is called a thallus, which means that it lacks xylem and phloem and therefore does not have true stem, true leaf or true root.
The thallus is anchored to the substrate by rhizoids.
Regardless of the location of the archegonia (on the thallus surface or up on an archegoniophore), the sperm finds the egg, syngamy is completed and the zygote is formed in the venter of the old archegonium.
koning.ecsu.ctstateu.edu /Plant_Biology/liverwort.html   (1363 words)

  
 [No title]
-internally the sporophyte has a cylinder of vascular tissue with a cluster of water conducting cells in the center of the axis.
-Lack of vascular tissue should immediately indicate to you that the bodies of both the gametophyte and sporophyte are simple and not very thick so that there is no need for water to be distributed to tissues that are some distance from the surface.
-The thallus is attached to its substrate by rhizoids.
www.d.umn.edu /biology/courses/bio3601/outlinefeb24.htm   (1368 words)

  
 The Botanical Society of America's American Journal of Botany Abstracts Online - Reiterative Production and Deformation ...   (Site not responding. Last check: 2007-10-31)
Abstract: The thallus of the lichen Ramalina menziesii Tayl.
Study of net tissue with transmission electron microscopy reveals that the cortical cells are surrounded by a succession of cell walls alternating with layers of an electron-transparent matrix substance.
In the course of thallus growth the cortical cell walls are continually deformed and new ones constructed.
www.botany.org /Abstracts/82-11-1358.php   (319 words)

  
 Basal plants   (Site not responding. Last check: 2007-10-31)
Without vascular tissue to conduct food and water efficiently, their growth is somewhat limited and they are typically small in size.
The large, flat, "leafy" portion of the plant is called the thallus.
The "leafy" green portions of the plant are the gametophytes, which often grow in dense mats that are highly adapted to absorb and retain water.
www.usd.edu /biol/labs/162/DiversityLabs/02Basalplants.html   (2951 words)

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