Search results
Results from the WOW.Com Content Network
The consensus classification produced by the Pteridophyte Phylogeny Group classification in 2016 (PPG I) places all extant (living) lycophytes in the class Lycopodiopsida. [11] There are around 1,290 to 1,340 such species. [12] [13] [11] For more information on the classification of extant lycophytes, see Lycopodiopsida § Classification.
Lycopodiopsida is a class of vascular plants also known as lycopsids, [1] lycopods, or lycophytes. Members of the class are also called clubmosses , firmosses , spikemosses and quillworts . They have dichotomously branching stems bearing simple leaves called microphylls and reproduce by means of spores borne in sporangia on the sides of the ...
Bacterial phyla constitute the major lineages of the domain Bacteria.While the exact definition of a bacterial phylum is debated, a popular definition is that a bacterial phylum is a monophyletic lineage of bacteria whose 16S rRNA genes share a pairwise sequence identity of ~75% or less with those of the members of other bacterial phyla.
Bacteria (prokaryotes, together with Archaea) share many common features. These commonalities include the lack of a nuclear membrane, unicellularity, division by binary-fission and generally small size. The various species can be differentiated through the comparison of several characteristics, allowing their identification and classification.
The term phylum was coined in 1866 by Ernst Haeckel from the Greek phylon (φῦλον, "race, stock"), related to phyle (φυλή, "tribe, clan"). [4] [5] Haeckel noted that species constantly evolved into new species that seemed to retain few consistent features among themselves and therefore few features that distinguished them as a group ("a self-contained unity"): "perhaps such a real and ...
Their formal classification varies as of July 2019; this category is for the broadest circumscription including the extinct zosterophylls (e.g. subdivision Lycophytina of Kenrick & Crane (1997)). Subcategories
Bacillota (synonym Firmicutes) is a phylum of bacteria, most of which have gram-positive cell wall structure. [2] The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature.
Lycopods reproduce asexually by spores. The plants have an underground sexual phase that produces gametes, and this alternates in the lifecycle with the spore-producing plant. The prothallium developed from the spore is a subterranean mass of tissue of considerable size, and bears both the male and female organs (antheridia and archegonia). [6]