This will be discussed in the following section. The benthic diatoms (Bacillariophyceae, order Pennales) C. closterium (for freshwater environments) and Nitzschia palea (for freshwater environments) have demonstrated to be good target organisms for whole-sediment bioassays.
What are the characteristics of Closterium?
Closterium cells are crescent-shaped or elongate and lack spines. Some are quite straight and needle-like, while others are much broader with curved ends. The ends of the cell are usually tapered and may be pointed or rounded. Each semicell has a single axial, ridged chloroplast with at least one pyrenoid.
What type of protist is Closterium?
Closterium is a genus of unicellular charophyte green algae in the family Closteriaceae.
Does Closterium have chlorophyll?
If, as is generally held (1), it is a cryptophyte, it is equally anomalous in lacking chlorophyll c.
How many cells make up Closterium?
Closterium sp. are lunate (moon-shaped) and vary from very long and thin to the thicker forms as seen here. Scenedesmus sp. are small forms usually comprised of four cells, but some species may have up to twelve cells.
Is Closterium motile?
Spirogyra and Closterium exhibit active motility. This motility is associated with the secretion of pectic mucilage from the cells. The gliding of these cells is not directed toward light but photosynthesis is the energy source for it.
How do Closterium reproduce?
Reproduction in Closterium:
Sexual reproduction takes place by conjugation of amoeboid gametes from two conjugating cells. In some cases, a rudimentary conjugation tube may be formed between them; in others, sister cells probably conjugate.
How do desmids eat?
Like other plants that contain chlorophyll, desmids live by capturing the sun’s energy (photosynthesis). From carbon dioxide dissolved in the water they manufacture sugar and starch as food.
How do desmids move?
Many Desmids secrete mucilage from pores in the cell wall. With this they can move towards light or avoid too bright light. … Desmids reproduce by fission, the cells divide. It is an interesting to see this whole process in desmids.
What type of bacteria is oscillatoria and what is its purpose?
Oscillatoria | |
---|---|
Domain: | Bacteria |
Phylum: | Cyanobacteria |
Class: | Cyanophyceae |
Order: | Oscillatoriales |
Is Cosmarium unicellular?
Cosmarium is a non-motile, freshwater member of division Chlorophyta (green algae). … Euglena is a motile, unicellular, freshwater organism traditionally classified as a plant-like member of the kingdom protista. Euglena is an elongate unicell containing a large haploid nucleus and several green disc shaped chloroplasts.
How do Chlamydomonas reproduce?
Chlamydomonas sexually reproduces through the involvement of two gametes: Isogamy: Both of the gametes that are produced are similar in shape, size and structure. These are morphologically similar but physiologically different. Also, Isogamy is most common in sexually reproducing Chlamydomonas.
Where is Volvox found?
Volvox can be found in ponds, puddles, and bodies of still fresh water throughout the world. As autotrophs, they contribute to the production of oxygen and serve as food for a number of aquatic organisms, especially the microscopic invertebrates called rotifers.
How do diatoms move?
Movement in diatoms primarily occurs passively as a result of both water currents and wind-induced water turbulence; however, male gametes of centric diatoms have flagella, permitting active movement for seeking female gametes. … Diatoms are a type of plankton called phytoplankton, the most common of the plankton types.
How does a spirogyra move?
Spirogyra form long filaments, and it’s the bending and curving of these filaments that allow these protists to move, albeit slowly, to orient themselves towards light. And remember, they need light because they undergo photosynthesis.
What is the size of microalgae?
Microalgae are unicellular species, commonly found in marine and freshwater with the size ranging from a few micrometers to a few hundreds of micrometers. It has been estimated that 2 × 105 to 8 × 105 species exist.
Where are most green algae found?
Most green algae occur in fresh water, usually attached to submerged rocks and wood or as scum on stagnant water; there are also terrestrial and marine species. Free-floating microscopic species serve as food and oxygen sources for aquatic organisms.
What species is brown algae?
brown algae, (class Phaeophyceae), class of about 1,500 species of algae in the division Chromophyta, common in cold waters along continental coasts. Species colour varies from dark brown to olive green, depending upon the proportion of brown pigment (fucoxanthin) to green pigment (chlorophyll).
Are Desmids prokaryotic or eukaryotic?
For example, like all eukaryotes, the desmid cell contains a membrane-bound nucleus as well as organelles, a cell wall that does not contain peptidoglycan (not all eukaryotes have cell walls), linear DNA, and a cytoskeleton, among other features.
Where could you find a Desmid?
The Desmidiales comprise around 40 genera and 5,000 to 6,000 species, found mostly but not exclusively in fresh water. Many species may be found in the fissures between patches of sphagnum moss in marshes. With a pH level of approximately 4.0, sphagnum peat provides the ideal environment for this flora.
What does Desmid look like?
desmid, (order Desmidiales), order of single-celled (sometimes filamentous or colonial) microscopic green algae, comprising some 5,000 species in about 40 genera. … One of the more common desmid genera, the sickle-shaped Closterium, often contains gypsum crystals in cell vacuoles.
Are algae protists?
Plant-like protists are called algae. They include single-celled diatoms and multicellular seaweed. Like plants, algae contain chlorophyll and make food by photosynthesis.
What is the economic importance of Spirogyra?
Some species of Spirogyra are used as a source of food in different parts of the world as they are rich in vitamins and minerals. Green algae like Spirogyra are also an important part of the aquatic ecosystems as they are photosynthetic and thus provide oxygen to other organisms in the water.
Is Spirogyra motile or nonmotile?
In Spirogyra, gametes are non-motile and sexual reproduction takes place by conjugation. ( Sargassum belongs to Phaeophyceae group of algae. They are commonly called as ‘brown algae’ and contain photosynthetic pigments chlorophyll a and c.
Is Spirogyra a colonial?
Spirogyra is a unicellular green algae that grows in long, filamentous colonies, making it appear to be a multicellular organism. Even though it is technically unicellular, its colonial nature allows us to classify its life cycle as haplontic.
Are diatoms and desmids same?
Additional Information: Difference between Diatoms and Desmids; – Diatoms are stramenopila algae whereas Desmids are chlorophyte. – The cell membrane of diatoms consists of silica whereas that of desmids consists of cellulose and pectins (like plants) . … – They are Free swimming types of algae.
Are desmids protists?
(Project Update: Diatoms & Desmids of the U.S.A.) Desmids are an order of single celled green algae with approximately 40 genera and 6,000 species. … However, as more is learned about their internal chemistry, it is becoming more common to place them in the Kingdom Protista with all other forms of micro-algae.
What do all desmids have in common?
Desmids are green algae, which most botanists consider to be the earliest-evolved plants. One of the ways that we can tell they are closely related to plants is they share the same photosynthetic pigments — chlorophylls a and b — and so have the same familiar green glow.
Are Desmids golden algae?
What are Desmids Golden Algae? Desmids are also known as golden algae or golden-brown algae because of their distinctive golden colour, which is caused by the pigment fucoxanthin and the use of oil droplets as food reserves.
What water is used to make Desmids?
Desmids can be found in fresh water, preferably clean, clear water. A few species occur in (slightly) brackish water. They can be found at the bottom, on aquatic plants or free-floating in the water.
Are Desmids unicellular or multicellular?
desmids. desmids A group of green algae (division Chlorophyta) which are basically unicellular but have two distinct halves, or ‘semicells’. The cells are usually solitary but in a few species they may form irregular or filamentous colonies.
Is Oscillatoria harmful?
Although unsightly, most mats are not known to pose any environmental or human health risks. However, there are some species of Oscillatoria and related forms of filamentous blue-greens, that have been shown to produce toxins.
Is Oscillatoria toxic?
But the most concerning difference between an Oscillatoria bloom and one dominated by Microcystis is that the latter is a notorious toxin producer, and the toxins can be harmful to animals, including humans. … While harmful is usually synonymous with toxin, there are other harmful effects of HABs.
What does Oscillatoria look like?
Description: Oscillatoria is a filamentous blue-green alga that can be found throughout North Carolina. Its filaments are motile and weave into thin mats that coat sediment and other submerged surfaces. The bright blue and blue-green mats are commonly described as looking like spilled paint.