What is pseudoparenchymatous algae?
This tissue organization is found in Ulva (Chlorophyta) and many of the brown algae. Pseudoparenchymatous algae are made up of a loose or close aggregation of numerous, intertwined, branched filaments that collectively form the thallus, held together by mucilages, especially in red algae.
What are parenchymatous cells in plants?
Parenchyma cells are the foundation of a plant as reproductive cells (spores, gametes) are parenchymatous in nature; Single parenchyma cell of a zygote has an ability to develop into an entire plant. These cells are called “totipotent” cells
What is parenchyma in biology?
Parenchyma is a type of simple permanent tissue that makes a major part of ground tissues in plants, where other tissues like vascular tissues are embedded. They are non-vascular and composed of simple, living and undifferentiated cells, which are modified to perform various functions.
What is the phylogeny of chloroplasts in algae?
Phylogeny based on plastid not nucleocytoplasmic genealogy: These algae have "primary" chloroplasts, i.e. the chloroplasts are surrounded by two membranes and probably developed through a single endosymbiotic event.
Is red algae a Pseudoparenchymatous?
Lemanea sp. (red alga), a pseudoparenchymatous thallus of closely arranged cells forming a cartilaginous tube surrounding a central uniseriate axis.
What is pseudo Parenchymatous?
Definition of pseudoparenchyma : compactly interwoven short-celled filaments especially in fungi that resemble parenchyma of higher plants.
What is algae Cortication?
Cortication – elaboration of polysiphonous condition where pericentral. cells continue to proliferate.
What is Parenchymatous cell?
Parenchyma is a type of simple permanent tissue that makes a major part of ground tissues in plants, where other tissues like vascular tissues are embedded. They are non-vascular and composed of simple, living and undifferentiated cells, which are modified to perform various functions.
What is parenchymatous thallus in algae?
Seaweeds made up of "boxy" cells like those of higher plants are termed parenchymatous. Others in cross-section appear to be parenchymatous but are in fact really made up of interwoven filaments.
What is Polysiphonia used for?
Valued as a food plant, Polysiphonia retain their red coloring and gelatinous form, even when heated. These red algae are often used as a vegetable substitute for gelatin in puddings, ice cream, and toothpaste. As its generic name implies, Polysiphonia forms many "pipes" or branches in its typical configuration.
What are globule and nuclei?
'Globule' and 'Nucule' are found in Chara. The globule is the male reproductive part and the nucule is the female reproductive part. The nucule or the oogonium lies above the globule or antheridium. Chara is freshwater, green alga found submerged in shallow water ponds, tanks, lakes, and slow running water.
What is Siphonaceous algae?
siphonaceous (siphoneous) Applied to algae in which the thallus is not divided up by septa, i.e. the many nuclei are not compartmentalized into cells. The typical siphónaceous alga has a large central vacuole surrounded by a layer of protoplasm, containing nuclei and chloroplasts, which lines the cell wall.
What is parenchyma cell?
Parenchyma Cells Definition. In plants, parenchyma is one of three types of ground tissue. Ground tissue is anything that is not vascular tissue or part of the dermis ( skin) of the plant. In contrast to collenchyma and sclerenchyma cells, parenchyma cells primarily consists of all of the simple, thin walled, undifferentiated cells which form ...
What is the function of parenchyma cells?
One of the most important functions of parenchyma cells is that of healing and repair. Parenchyma cells are unique in their meristematic nature. This means that the cells are pluripotent, having the ability to divide into a number of different cells. This plays an important role in how a plant can heal itself after a wound.
Why do parenchyma cells need sugar?
These other parenchyma tissues need the sugars because they are internal and do not contain chloroplasts with which to create their own energy.
What is the pressure between the parenchyma cells and their neighbors called?
This both creates a pressure between the parenchyma cells and their neighbors (called turgor pressure) and also allows the plant to store enormous amounts of water and nutrients. The thin walls of the parenchyma cells also allow the easy passage of sugars created in the leaves. In fact, most photosynthesis takes place within specialized parenchyma ...
Why are parenchyma cells important?
This is important for the growth and repair functions of the parenchyma cells.
Which cell type produces the majority of photosynthesis?
While the other cell types provide much of the support and foundation on which the parenchyma cells operate, they produce a majority of the photosynthesis products. Simply through sheer numbers, parenchyma cells outnumber the other types. The chlorenchyma cells specifically do the majority of the photosynthesis.
Which cells have thicker walls?
Parenchyma cells are notable for their thin walls, and for being alive at maturity. Collenchyma cells tend to develop thicker secondary cell walls, to support structure. Sclerenchyma cells get both thicker walls and die off at maturity, producing tissues like bark and vascular tissue. The parenchyma cells have thinner walls ...
What are the unicellular types of algae?
The range of thallus organization in algae may be classified as follows: 1. Unicellular. Motile and non-motile. ADVERTISEMENTS:
Why are structural and cellular organizations important in the classification of algae?
Structural and cellular organizations are important characters in the classification of algae and in establishing the inter-relationship among them. Similarities of some morphological structures are seen among various classes of algae.
How are aggregations formed?
Aggregates are formed by the collection of single cells to make thallus. Unlike the coenobium the aggregation of cells does not have fixed number of cells shape or size. The cells are aggregated into more or less irregular colony like mass. When the cells divide, the daughter cells remain in same gelatinous mass.
Which cell type is absent in Cyanophyceae?
Flagellated vegetative cells are absent in Cyanophyceae, Phaeophyceae, Rhodophyceae, Bacillariophyceae. Nature of flagellation, type and number of flagella and the attachment of flagella, is an important character in classification.
Is the thallus always a thallus?
In this article we will discuss about the thallus organisation found in algae. The plant body in algae is always a thallus. It is not differentiated in root, stem and leaves .
Is the vegetative phase motile?
This feature gets further elaborated in many forms where the vegetative phase is completely non-motile. They are motile in the re-productive phase only. Such developments ultimately lead to palmelloid, dendroid and coccoid habits.
Is pseudoparenchymatous algae densely packed?
Through the establishment of secondary intercellular connections the cells of pseudoparenchymatous algae may be densely packed and firmly coherent (e.g., Dumontia, Rhodophyceae) or, the association may be loose and the component filaments can easily be separated by pressure (e.g., Castanea, Phaeophyceae).
What is the difference between algae and fungi?
The core difference between algae and fungi is that algae are a unicellular organism that is autotrophs while fungi are organisms that are heterotrophs.
What kingdom do algae belong to?
Algae belong to Protista kingdom while fungi belong to the fungi kingdom. Examples of algae are seaweed and freshwater moss while fungi are mushrooms, yeast, and truffles.
Do algae have chlorophyll?
Algae have chlorophyll while fungi do not have chlorophyll. Algae can survive in light while fungi can survive in darkness. Fungi have a cell wall made of chitin while that of algae consist of cellulose. Fungi are multinucleated while algae are uninucleated.
Overview
Morphology
A range of algal morphologies is exhibited, and convergence of features in unrelated groups is common. The only groups to exhibit three-dimensional multicellular thalli are the reds and browns, and some chlorophytes. Apical growth is constrained to subsets of these groups: the florideophyte reds, various browns, and the charophytes. The form of charophytes is quite different from those of …
Etymology and study
The singular alga is the Latin word for 'seaweed' and retains that meaning in English. The etymology is obscure. Although some speculate that it is related to Latin algēre, 'be cold', no reason is known to associate seaweed with temperature. A more likely source is alliga, 'binding, entwining'.
The Ancient Greek word for 'seaweed' was φῦκος (phŷkos), which could mean either the seawee…
Classifications
The committee on the International Code of Botanical Nomenclature has recommended certain suffixes for use in the classification of algae. These are -phyta for division, -phyceae for class, -phycideae for subclass, -ales for order, -inales for suborder, -aceae for family, -oidease for subfamily, a Greek-based name for genus, and a Latin-based name for species.
Relationship to land plants
The first land plants probably evolved from shallow freshwater charophyte algae much like Chara almost 500 million years ago. These probably had an isomorphic alternation of generations and were probably filamentous. Fossils of isolated land plant spores suggest land plants may have been around as long as 475 million years ago.
Physiology
Many algae, particularly members of the Characeae species, have served as model experimental organisms to understand the mechanisms of the water permeability of membranes, osmoregulation, turgor regulation, salt tolerance, cytoplasmic streaming, and the generation of action potentials.
Phytohormones are found not only in higher plants, but in algae, too.
Symbiotic algae
Some species of algae form symbiotic relationships with other organisms. In these symbioses, the algae supply photosynthates (organic substances) to the host organism providing protection to the algal cells. The host organism derives some or all of its energy requirements from the algae. Examples are:
Lichens are defined by the International Association for Lichenology to be "an a…
Lifecycle
Rhodophyta, Chlorophyta, and Heterokontophyta, the three main algal divisions, have lifecycles which show considerable variation and complexity. In general, an asexual phase exists where the seaweed's cells are diploid, a sexual phase where the cells are haploid, followed by fusion of the male and female gametes. Asexual reproduction permits efficient population increases, but less variation is possible. Commonly, in sexual reproduction of unicellular and colonial algae, two sp…