Vaucheria
Occurrence Majority of them are fresh water. They are also found on moist soil. They form dark green mats. General structure Vegetative structure The thallus is filamentous. The filament is cylindrical, branched, tubular, erect coenocytic. The filament is attached to the substratum by hepteron. Hepteron is colourless branched rhizoid like structure. Filament increases in length […]
Volvox
Occurrence Volvox is freshwater algae. It makes water green. It appears in the spring. Vegetative structure Volvox forms colony. The colony of volvox is called coenobium (if the colony having fixed number of cells). It is spherical in shape. Each colony has number of cells from 500 to 50,000. The interior of the colony […]
Chara
Occurrence: Chara is a fresh water, green alga found submerged in shallow water ponds, tanks, lakes and slow running water. C. baltica is found growing is brackish water and C. fragilis is found in hot springs. Chara is found mostly in hard fresh water, rich in organic matter, calcium and deficient in oxygen. Chara plants […]
Algae: Life cycles
Following types of life histories are found in algae: (a) Haplontic Monophasic: It is a primitive life cycle. In this case, vegetative plant body remains haploid. Gametes are produced by mitosis and fuse to form diploid zygote. First division in zygote is meiosis. It forms haploid vegetative body. Thus zygote is the only diploid stage […]
Cyanophyceae
The Cyanophyceae or blue-green algae are, today, usually referred to as the cyanobacteria (bluegreen bacteria). The term cyanobacteria acknowledges that these prokaryotic algae are more closely related to the prokaryotic bacteria than to eukaryotic algae. Cyanobacteria have chlorophyll a (some also have chlorophyll b or d), phycobiliproteins, glycogen as a storage product, and cell walls […]
Algae Plastids
The basic type of plastid in the algae is a chloroplast, a plastid capable of photosynthesis. Chromoplast is synonymous with chloroplast; in the older literature a chloro plast that has a color other than green is often called a chromoplast. A proplastid is a reduced plastid with few if any thylakoids. A proplastid will usually develop into […]
Algal Cell walls
In general, algal cell walls are made up of two components: (1) the fibrillar component, which forms the skeleton of the wall, and (2) the amorphous component, which forms a matrix within which the fibrillar component is embedded. The most common type of fibrillar component is cellulose, a polymer of 1,4 linked -D-glucose. Cellulose is […]
Algae: Flagellation
The flagella of the green alga Chlamydomonas have been used as a model of flagellar structure. Flagella structure has been highly conserved throughout evolution, images from Chlamydomonas are virtually indistinguishable from flagella (or cilia – a term for a short flagellum) of mammalian cells including human sperm and certain epithelia. Chlamydomonas has been chosen because […]
Algae: Cell Structure
There are two basic types of cells in the algae, prokaryotic and eukaryotic. Prokaryotic cells lack membrane-bounded organelles (plastids, mitochondria, nuclei, Golgi bodies, and flagella) and occur in the cyanobacteria. The remainder of the algae are eukaryotic and have organelles. A eukaryotic cell is often surrounded by a cell wall composed of poly saccharides that are […]
Phycology
Phycology or algology is the study of the algae. The word phycology is derived from the Greek word phykos, which means “seaweed.” The term algology, described in Webster’s dictionary as the study of the algae, has fallen out of favor because it resembles the term algogenic which means “producing pain.” The algae are thallophytes (plants […]