Habitat, Habit and External Features of Amphioxus
Amphioxus has long been of considerable interest to zoologists and there has been a great deal of investigation into its structure and development. While there…
Biology
Morphological Affinities of the Chordates and Echinoderms
The origin and affinities of chordates and echinoderms have long been a subject of interesting speculation. Relationships between creatures are postulated mainly on grounds of…
Morphological and Physiological Description of Urochordata
Urochordata is subdivided into three orders, the Larvacea, the Ascidiacea and the Thailiacea. Members of the Larvacea are free-swimming and they retain the larval features…
Concise Description of Hemichordate Animals
This class is subdivided into two orders, the Enteropneusta and the Pterobranchia. The order Enteropneusta contains the acorn-worms balanoglossus and Dolichoglossus,which are free-living. They burrow…
7 Characteristic Features of Chordate Animals
In common with arthropods and annelids, chordates and chordate animals are bilaterally symmetrical and metamerically segmented; they possess, however, certain distinctive features not found in…
Structural Significance of Sclerenchyma Cells
The structure and position of this tissue also indicate its primary strengthening functions, but it is clearly distinguishable from collenchyma. Two widely diverse forms of…
Structural Significance of Collenchyma Tissues
This is a simple tissue consisting of one type of cell only the structure and position of the cells indicate the primary supporting function. Collenchyma…
The History and Evolutionary Trends of Vascular Plants
The evolution of the fully-erect land habit in plants has been the result of a capacity for great variation in cell types to meet the…
Concise Description of the Physiology of Sponges
The Physiology of Sponges In describing the physiology of sponges, we shall first tak a look…
Morphological Description of Sponges
All sponges are aquatic, the majority living in the sea where they are found at all depths from the intertidal zone to the deepest abysses….