Search results
Results from the WOW.Com Content Network
The generally accepted parts of modern cell theory include: All known living things are made up of one or more cells [13] All living cells arise from pre-existing cells by division. The cell is the fundamental unit of structure and function in all living organisms. [14] The activity of an organism depends on the total activity of independent ...
The dicotyledons, also known as dicots (or, more rarely, dicotyls), [2] are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, that the seed has two embryonic leaves or cotyledons. There are around 200,000 species within this ...
Non-flowering seed plant approx. 1,000 They are a group of seed producing plants, which include Coniferophyta,Ginkgophyta,Cycadophyta and Gnetophyta. Angiosperms: Flowering plants approx. 300,000 They are divided into two main classes the monocotyledons and dicotyledons, produce seeds that are protected by fruits.
Botany is a natural science concerned with the study of plants.The main branches of botany (also referred to as "plant science") are commonly divided into three groups: core topics, concerned with the study of the fundamental natural phenomena and processes of plant life, the classification and description of plant diversity; applied topics which study the ways in which plants may be used for ...
The spermatophytes were traditionally divided into angiosperms, or flowering plants, and gymnosperms, which includes the gnetophytes, cycads, [5] ginkgo, and conifers. Older morphological studies believed in a close relationship between the gnetophytes and the angiosperms, [ 6 ] in particular based on vessel elements .
The acid-growth hypothesis is a theory that explains the expansion dynamics of cells and organs in plants. It was originally proposed by Achim Hager and Robert Cleland in 1971. [1] [2] They hypothesized that the naturally occurring plant hormone, auxin (indole-3-acetic acid, IAA), induces H + proton extrusion into the apoplast.
With the introduction of phyletic thinking in taxonomy (from the system of Eichler 1875–1878 onwards) the predominant theory of monocot origins was the ranalean (ranalian) theory, particularly in the work of Bessey (1915), [2] which traced the origin of all flowering plants to a Ranalean type, and reversed the sequence making dicots the more ...
The three-domain system adds a level of classification (the domains) "above" the kingdoms present in the previously used five- or six-kingdom systems.This classification system recognizes the fundamental divide between the two prokaryotic groups, insofar as Archaea appear to be more closely related to eukaryotes than they are to other prokaryotes – bacteria-like organisms with no cell nucleus.