Algae

Algae exist in environments ranging from oceans, rivers, and lakes to ponds, brackish waters and even snow. Algae are usually green, but they can be found in a variety of different colours. For instance, algae living in snow contain carotenoid pigments in addition to chlorophyll, hence giving the surrounding snow a distinctive red hue. Multicellular examples of algae include the giant kelp and brown algae. Unicellular examples include diatoms, Euglenophyta and Dinoflagellates.

Most algae require a moist or watery environment; hence, they are ubiquitous near or inside water bodies. Anatomically, they are similar to another major group of photosynthetic organisms – the land plants. However, that is where the differences end as algae lack many structural components typically present in plants, such as true stems, shoots, and leaves. Furthermore, they also do not have vascular tissues to circulate essential nutrients and water throughout their body.

Characteristics of Algae
Specific general characteristics of algae are common to plants as well as animals.

For instance, algae can photosynthesize like plants, and they possess specialized structures and cell-organelles, like centrioles and flagella, found only in animals. Listed below are some of the general characteristics of algae.

Algae are photosynthetic organisms Algae can be either unicellular or multicellular organisms Algae lack a well-defined body, so, structures like roots, stems or leaves are absent Algaes are found where there is adequate moisture. Reproduction in algae occurs in both asexual and sexual forms. Asexual reproduction occurs by spore formation. Algae are free-living, although some can form a symbiotic relationship with other organisms. Types of Algae There are many types of algae. However, these are some of the more prominent types:

Red Algae Also called Rhodophyta, it is a distinctive species found in marine as well as freshwater ecosystems. The pigments phycocyanin and phycoerythrin are responsible for the characteristic red colouration of the algae. Other pigments that provide green colouration (such as chlorophyll a) are present. However, they lack chlorophyll b or beta-carotene.

Green Algae It is a large, informal grouping of algae having the primary photosynthetic pigments chlorophyll a and b, along with auxiliary pigments such as xanthophylls and beta carotene.

Higher organisms use green algae to conduct photosynthesis for them. Other species of green algae have a symbiotic relationship with other organisms.

Members are unicellular, multicellular, colonial and flagellates. Prominent examples of green algae include Spirogyra, Ulothrix, Volvox, etc.