1. Lacking elasticity; unyielding or unadaptable. See Synonyms at stiff. 2. Economics Of, relating to, or being a good for which changes in price have little effect on the quantity demanded or supplied: the inelastic demand for cigarettes.
The classification of algae is complex and somewhat controversial, especially concerning. the blue-green algae (Cyanobacteria), which are sometimes known as blue-green. bacteria or Cyanophyta and sometimes included in the Chlorophyta. These topics are. not covered in detail this document.
The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, Spirogyra and the stoneworts. No definition of algae is generally accepted. One definition is that algae have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells. Some authors exclude all prokaryotes and thus do not consider cyanobacteria (blue-green algae) as algae.