Does any one know how Rhodophyta (red algae) move? and also how they get their nutrition?????????

Question

thanks if u can help!

Answer 1

Rhodophyta (Red algae) -

Students at Hopkins Marine Station have done research projects on these red algae: Antithamnion, Ceramium, Pugetia, Porphyra, Gelidium, Corallinales (articulated or non-geniculate), Mastocarpus, Mazzaella, Prionitis, Chondracanthus, Gracilariopsis, Fauchea, Botryocladia, Plocamium, Microcladia, Polysiphonia, Delesseria, Botryoglossum.


With over 4,000 species, most from marine habitats, the red algae range in morphology from simple unicells to unbranched and branched filaments to complex multiaxial uprights and crusts.

Their pigments include chlorophyll a and the phycobiliproteins, red phycoerythrin (often the dominant pigment) and blue phycocyanin, as well as carotenes, lutein, zeaxanthin. Most reds have a complex life history with three phases: tetrasporophyte, gametophyte and carposporophyte. In fact, the post-fertilization development of the carposporophyte is the best part of each species' story. Red algae have no flagellated stages; their non-swimming sperm are called "spermatia."

From the above one can answer you question.

1) plants or rather algae of this division do not show locomototion ( That is they do not move from one place to another on their own . They are however carried passively by the currents). Even their sperms are non motile.

2) They are aututrophic in nutrition and do PHOTOSYNTHESIS. Their starch is bit different from the one prepared by other photosynthetic plants. It is called 'Floridian starch'

3) Red algae often attach to submerged stones or anchor to other marine plants and are able to withstand the wave and tidal forces of the intertidal zone. Because of their durability, fragments of red algae that survive the winter, or are buried under sand for months, can grow again into healthy plants under favorable environmental conditions.


The red colour is due to the dominant pigment phycoerythrin; but that pigments acts as a helping pigment to normal chlorophyll a pigment.

for good pictures of some of them ; kindly click on the links below--

1) Microcladia
http://www.msc.ucla.edu/oceanglobe/specimenphotographs/Plants/Rhodophyta/Microcladia.JPG

2) Polysiphonia
http://www.resnet.wm.edu/~mcmath/bio205/diagrams/botun05a.gif

While there are more than 4,000 catalogued species of red algae worldwide, most are found in tropical marine waters, and only a few are freshwater species. Polysiphonia, a common genus of marine red algae, is red in color because of the pigment phycobilin, which masks the green color of the chlorophyll responsible for photosynthesis. As a red-colored plant, Polysiphonia is well suited to absorb the green and blue-green light that typically penetrates the deeper seawater where these red algae thrive.

Answer 2

here is the answer::;

Fossil record
The oldest fossil identified as a red alga is also the oldest fossil eukaryote that belongs to a specific modern taxon. Bangiomorpha pubescens, a multicellular fossil from arctic Canada, strongly resembles the modern red alga Bangia despite occurring in rocks dating to 1200 million years ago.[2]

Red algae are important builders of limestone reefs. The earliest such coralline algae, the solenopores, are known from the Cambrian Period. Other algae of different origins filled a similar role in the late Paleozoic, and in more recent reefs.

How pit connections are formed
Pit connections and pit plugs are unique and distinctive features of red algae that form during the process of cytokinesis following mitosis. In red algae, cytokinesis is incomplete. Typically, a small pore is left in the middle of the newly formed partition. The pit connection is formed where the daughter cells remain in contact.

Shortly after the pit connection is formed cytoplasmic continuity is blocked by the generation of a pit plug, which is deposited in the wall gap that connects the cells.

Connections between cells having a common parent cell are called a primary pit connections. Because apical growth is the norm in red algae, most cells have two primary pit connections, one to each adjacent cell.

Connections that exist between cells not sharing a common parent cells are labeled secondary pit connections. These connections are formed when an unequal cell division produced a nucleated daughter cell that then fuses to an adjacent cell. Patterns of secondary pit connections can be seen in the order Ceramiales.

How pit plugs are formed
After a pit connection is formed, tubular membranes appear. A granular protein, called the plug core, then forms around the membranes. The tubular membranes eventually disappearWhile some orders of red algae simply have a plug core, others have an associated membrane at each side of the protein mass, called cap membranes. The pit plug continues to exist between the cells until one of the cells dies. When this happens, the living cell produce a layer of wall material that seals off the plug


Function
It is thought that the pit connections serve as an avenue for cell to cell communication and/or symplastic transport in red algae. While the presence of the cap membrane could inhibit this transport between cells, it has been hypothesized that the tubular plug cores serve as a means of transport.

Answer 3

They don't move except by floating (no flagella), and they get their food by photosynthesis.