nannandrous [ na′nan·drəs] (botany) Pertaining to species of plants in which male members are markedly smaller than females, such as in some algal species of Oedogonium that have antheridia produced in special dwarf filaments.
What is Nannandrous and Macrandrous?
nodulosum etc. In dioecious macrandrous species antheridia and oogonia are produced on separate male and female plants of normal size. (ii) Nannandrous: The female or oogonia bearing plants are normal. The antheridia are produced on special type of small or dwarf plants, known as Dwarf males or Nannandria.
What are Nannandrous species?
In nannandrous species, filaments producing antheridia and oogonia show morphological distinction. The antheridia, which are much smaller than the oogonia, are called dwarf male. Nannandrous species are always dioecious; i.e. antheridia and oogonia are always produced on different filaments.
What are Macrandrous species?
Definition of macrandrous : having oogonia and antheridia borne on the same plant or on plants of similar size and form —used of green algae of the family Oedogoniaceae — compare nannandrous.
What is Nannandrium example?
noun. Botany. The single-celled male plantlet (dwarf male) of nannandrous green algae.
What is Nannandrous Oedogonium?
Nannandrous Type: The nannandrous species are always dioecious (heterothallic) i.e., antheridia and oogonia are borne on different filaments. In this type the antheridia develop on a very small filament termed as dwarf male or nannandrium.
What are Carpogonia give example?
: the egg-bearing portion of the female reproductive organ in some red algae.
What is Macrandrous Oedogonium?
Macrandrous Forms: Oedogonium macrandrous species can be monoecious or homothallic, if antheridia and oogonia are produced on same filament (Fig. 10, 11). Oedogonium macrandrous species can be dioecious or heterothallic if antheridia are produced on male plants and oogonia are produced on separate female plants.
Where is cell cap found?
Cap cell is found in the peripheral nervous system.
What is a Synzoospore?
In Vaucheria, the multiflagellate compound zoospores also known as synzoospores or coenozoospores are developed in these genus usually in aquatic forms. A single compound zoospore develops in a single zoosporangium. Any distal branch of the thallus may convert into a zoosporangium.
What is a Coenobium?
Definition of coenobium 1 : cenoby. 2 or less commonly coenobe or cenobe \ ˈsē(ˌ)nōb , ˈse(ˌ)- \ plural -s [New Latin, from Late Latin] : a usually spherical colony of unicellular organisms surrounded by a common investment especially : a colony having a definite number and specific arrangement of cells.
What is dwarf male in botany?
Definition of dwarf male 1 : a small plant of algae of the family Oedogoniaceae that consists of a few cells, develops from an androspore near the oogonium, is usually attached to the cell below it, and produces only spermatozoids. — called also nannander. 2 : complemental male.
What are the economic importance of algae?
It helps in maintaining the health of the marine ecosystem because algae are naturally absorbent of carbon dioxide and also provide oxygen to the water. 4. Fertilizer: Algae are rich in minerals and vitamins. So they also used as liquid fertilizer which helps in the repairing level of nitrogen present in the soil.
adjective
Designating certain green alga of the order Oedogoniales which produce small, unicellular male plantlets (dwarf males) during sexual reproduction.
Origin
Late 19th century; earliest use found in Mordecai Cooke (1825–1914), naturalist and mycologist. From post-classical Latin nannandrus (V. B. Wittrock 1875, in Prodromus Monographiae Oedogoniearum 2; from ancient Greek νάννος, variant of νᾶνος dwarf + -ανδρος see -androus) + -ous.
adjective
Designating certain green alga of the order Oedogoniales which produce small, unicellular male plantlets (dwarf males) during sexual reproduction.
Origin
Late 19th century; earliest use found in Mordecai Cooke (1825–1914), naturalist and mycologist. From post-classical Latin nannandrus (V. B. Wittrock 1875, in Prodromus Monographiae Oedogoniearum 2; from ancient Greek νάννος, variant of νᾶνος dwarf + -ανδρος see -androus) + -ous.
What is an oedogonium?
Oedogonium is a genus of filamentous, free-living green algae, first discovered in the fresh waters of Poland 1860 by W. Hilse and later named by German scientist K. E. Hirn. The morphology of Oedogonium is unique, with an interior and exterior that function very differently from one another and change throughout its life cycle. These protists reside in freshwater ecosystems in both hemispheres and are both benthic and planktonic in nature. Forming algal patches on water's surface, they interact closely with a multitude of other algae. These filamentous cell's life cycles include both sexual and asexual reproduction, depending on life cycle stage. Although quite common, Oedogonium is difficult to identify, since key ID factors are only present during reproduction, which is an uncommon life stage among this genus. Oedogonium has been found to be important in the fixation of heavy metals in freshwater ecosystems.
Why is oedogonium difficult to identify?
Although quite common, Oedogonium is difficult to identify, since key ID factors are only present during reproduction, which is an uncommon life stage among this genus. Oedogonium has been found to be important in the fixation of heavy metals in freshwater ecosystems.
How does oedogonium reproduce?
Oedogonium can reproduce asexually by fragmentation of the filaments, germination of aplanospores and akinetes, and through zoospores. In fragmentation, the filament splits apart and each fragment reproduces to form a fully functioning thallus.
How many ORFs does Oedogonium have?
It has four long open reading frames (ORFs), containing 99 different conserved genes. Two of these ORFs showed high similarities to genes not usually found in cpDNA (chloroplast DNAs). The chloroplastic genome of Oedogonium reveals character evidence for a close alliance between the OCC clade.
Is oedogonium monoecious?
Sexual reproduction in Oedogonium is oogamous; and can be monoecious or dioecious. Species may either be macrandrous (lacking dwarf males) or nannandrous (possessing dwarf males). Dwarf males are small, short, antheridium-producing filaments attached near the oogonia (female sex organ).
Where do oedogoniums live?
Oedogonium resides in freshwater ecosystems and prefers stagnant waters, such as small ponds, pools, roadside ditches, marshes, lakes, and reservoirs. It grows over a large pH range (7.3-9.6) and presents a wide tolerance to variation in nutrient type and amount in water. Cells exist either fastened to substrate at the bottom of the water system or free-floating within. When free-floating they form polyalgal patches (mats) on the water's surface to establish a relatively static habitat. Mats are created by interweaving multiple different algal filaments that are suspended in a gelatinous matrix. This matrix is a result of secretions by free floating thalli. Benthic cells are most often juvenile filaments and once matured they tend to let go, float to the top and form the mats. Oedogonium filaments typically appear during the warmer months, appearing at the end of June (north of the equator), and throughout July and August are found prevalent in polyalgal mats. Mats formed by Oedogonium are multi-species, associated with Spirogyra, Rhizoclonium, and Cladophora. Together these species use holdfast cells to grip one another in order to photosynthesize. These mats/patches are also known as algal blooms.
Is oedogonium haploid or diploid?
The life cycle of Oedogonium is haplontic. The egg from the oogonia and the sperm from the antheridia fuse and form a zygote which is diploid (2n). The zygote then undergoes meiosis and reproduces asexually to form the filamentous green alga which is haploid (1n).
