basal taxon

Examples of basal taxon in the following topics:

• Phylogenetic Trees

  • A lineage that evolved early from the root and remains unbranched is called basal taxon.
  • For example, if a branch point was rotated and the taxon order changed, this would not alter the information because the evolution of each taxon from the branch point was independent of the other.
  • A lineage that evolved early and remains unbranched is a basal taxon.

• The International Committee on Taxonomy of Viruses

  • To maintain an ICTV database on the Internet, that records the data that characterize each named viral taxon, together with the common names of each taxon in all major languages.
  • The name of a taxon has no status until it has been approved by ICTV, and names will only be accepted if they are linked to approved hierarchical taxa.
  • If no suitable name is proposed for a taxon, the taxon may be approved and the name be left undecided until the adoption of an acceptable international name, when one is proposed to and accepted by ICTV.
  • Names must not convey a meaning for the taxon which would seem to either exclude viruses which are rightfully members of that taxa, exclude members which might one day belong to that taxa, or include viruses which are members of different taxa.

• Basal Ganglia

  • One of the most intensively studied functions of the basal ganglia (BG) is its role in controlling precise eye movements.
  • The basal ganglia (or basal nuclei, ) are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit.
  • Two schematic drawings of coronal sections of human brain labelling the basal ganglia.
  • The basal nuclei are often referred to as the basal ganglia.
  • The main components of the basal nuclei are labeled in purple.

• Disorders of the Basal Ganglia

  • Basal ganglia disease refers to physical dysfunctions that occur when basal ganglia fail to suppress unwanted movements.
  • An example of a hypokinetic basal ganglia disease is Parkinsonism.
  • An example of a hyperkinetic basal ganglia disease is Huntington's Disease.
  • The basal ganglia is a collective group of structures in the brain .
  • This is a diagram of the main circuits of the basal ganglia.

• The Role of the Basal Ganglia in Movement

  • The basal ganglia (or basal nuclei) are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit.
  • Currently popular theories hold that the basal ganglia play a primary role in action selection.
  • One of the most intensively studied functions of the basal ganglia is their role in controlling eye movements.
  • This diagram shows the main circuits of the basal ganglia.
  • Two coronal slices have been superimposed to include the involved basal ganglia structures.

• Basement Membranes and Diseases

  • The basement membrane is the fusion of two lamina: the basal lamina and the reticular lamina (or lamina reticularis).
  • The lamina reticularis is attached to the basal lamina with anchoring fibrils (type VII collagen fibers ) and microfibrils (fibrillin).
  • The basal lamina layer can further be divided into two layers: the clear layer closer to the epithelium is called the lamina lucida, and the dense layer closer to the connective tissue is called the lamina densa.
  • The most notable examples of basement membranes are in the glomerular filtration of the kidney, by the fusion of the basal lamina from the endothelium of glomerular capillaries and the basal lamina of the epithelium of the Bowman's capsule; and between lung alveoli and pulmonary capillaries, by the fusion of the basal lamina of the lung alveoli and of the basal lamina of the lung capillaries, which is where oxygen and CO2 diffusion happens.

• The Deltaproteobacteria

  • Myxobacteria are included among the delta group of proteobacteria, a large taxon of Gram-negative forms.

• The Levels of Classification

  • The name at each level is also called a taxon.
  • Carnivora is the name of the taxon at the order level; Canidae is the taxon at the family level, and so forth.

• Hemidesmosomes

  • Hemidesmosomes are asymmetrical and connect the basal face of the expressing cell to the extracellular matrix or to other cells.
  • Hemidesmosomes (HD) are very small stud- or rivet-like structures on the inner basal surface of keratinocytes in the epidermis of skin.
  • Hemidesmosomes are asymmetrical and are found in epithelial cells connecting the basal face to other cells.
  • Electron microscopic analysis of the epidermal basement membrane zone (BMZ) reveals that it comprises a narrow and sometimes folded interface between the basal keratinocytes and the dermis.
  • Thin, extracellular, electron-dense lines, parallel to the plasma membrane, subjacent to the outer plaque are visible in one third of HDs and are termed sub-basal dense plates (SBDPs).

• Structure of the Skin: Epidermis

  • The stratum basale, also called the stratum germinativum, is the basal (base) layer of the epidermis. 
  • Millions of these new cells arise in the stratum basale on a daily basis. 
  • From the stratum basale, the keratinocytes move into the stratum spinosum, a layer so called because its cells are spiny-shaped cells. 
  • This entire cycle, from new keratinocyte in the straum basale to a dead cell flaked off into the air, takes between 25–45 days.
  • The stratum basale is primarily made up of basal keratinocyte cells, which can be considered the stem cells of the epidermis.