Division rhodophyta ppt

DIVISION RHODOPHYTA
(RED ALGAE)

RHODOPYTA (RED ALGAE)
Red algae have been the 1st eukaryotes formed by endosymbiosis involving photosynthetic prokaryotes.
Red algae are mostly multicellular
It exhibit some of the most complex life cycles It posses cellulose walls, chlorophyll a, some posses chlorophyll d (chloroplast is present but lacks grana)
Contains phycoerythrin, phycocyanin and allophycocyanin as accessory pigments.
flagella is absent in red algae as well as centrioles 5,000 species(approximate number of known species) are exclusively marine, abundant in fresh and warm water. Different species may be:
a. Free living
b. Epiphytic; or
c. Parasitic

STRUCTURE OF RED ALGAE
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Chiefly feathery
Branched-filamentous, sometimes ribbon-like with gelatinous suface
Smaller than most brown algae
Rarely more than 3 or 4 ft. long
Red in color, due to phycoerythrin
-a red pigment present with chlorophyll

The cell walls of Red algae:
>have cellulose as a framework but are mostly containing mucilages contains agars and carrageenans, both of which are polysaccharide.
Sold
as food many thickeners. >Corallinered algae that form layers of calcium carbonate in their cell walls. >Phycobilins and caratenoids gives many red algae.
Eg. Rhodymenia pseudopalmata- red or pink in color
>Halosaccion- species that do not contain as much as those accessory pigments, often blue-green or olive.

a. coralline

c. Halosaccion

b. Rhodymenia pseudopalmata REPRODUCTION
Asexual reproduction- by non-motile spores
Sexual reproduction- by non-motile heterogametes Male gametes- are spherical, non-motile, produced in antheridia.
-Carried by water to female sex organ
Carpognia- female sex organ of red algae, that, when fertilized, gives rise to carpospores. Trichogyne- the elongated tip of carpognium, to which a sperm may adhere.

LIFE CYCLE OF RED ALGAE
Consists of two alternating phases:
1.Haploid, gamete-bearing plants
2.Diploid, tetrasporic plants
oTetrasporophyte-