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Non-vascular plants are often among the first species to move into new and inhospitable territories, along with prokaryotes and protists, and thus function as pioneer species. [ citation needed ] Mosses and leafy liverworts have structures called phyllids that resemble leaves , but only consist of single sheets of cells with no internal air ...
Non-photochemical quenching (NPQ) is a mechanism employed by plants and algae to protect themselves from the adverse effects of high light intensity.It involves the quenching of singlet excited state chlorophylls (Chl) via enhanced internal conversion to the ground state (non-radiative decay), thus harmlessly dissipating excess excitation energy as heat through molecular vibrations.
Seed plants, which first appeared in the fossil record towards the end of the Paleozoic era, reproduce using desiccation-resistant capsules called seeds. Starting from a plant which disperses by spores, highly complex changes are needed to produce seeds. The sporophyte has two kinds of spore-forming organs or sporangia.
Cyanobacteria are globally widespread photosynthetic prokaryotes and are major contributors to global biogeochemical cycles. [29] They are the only oxygenic photosynthetic prokaryotes, and prosper in diverse and extreme habitats. [30] They are among the oldest organisms on Earth with fossil records dating back at least 2.1 billion years. [31]
A plant which completes its life cycle (i.e. germinates, reproduces, and dies) within two years or growing seasons. Biennial plants usually form a basal rosette of leaves in the first year and then flower and fruit in the second year. bifid Forked; cut in two for about half its length. Compare trifid. bifoliate
Photosynthetic organisms with plastids of different origin (such as brown algae) do not belong to the Archaeplastida. The archaeplastidans fall into two main evolutionary lines. The red algae are pigmented with chlorophyll a and phycobiliproteins , like most cyanobacteria, and accumulate starch outside the chloroplasts.
Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising over 3,000 species [1] of marine organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fans and sea whips) within three orders: Alcyonacea, Helioporacea, and Pennatulacea. [2]
The converse, where the cotyledons expand, throw off the seed shell and become photosynthetic above the ground, is epigeal germination. In water purification works, the hypogeal (or Schmutzdecke ) layer is a biological film just below the surface of slow sand filters .