Algae is a eukaryote among protozoa (some are prokaryotes, such as Cyanophyta). Mainly aquatic, without vascular bundles, it can carry out photosynthesis. They range in size from 1 micron long single-celled flagellates to 60-meter long large brown algae.

Algae can be composed of one or several cells, and many cells gather into a tissue-like structure. Filaments can be branched or unbranched. Some algae are unicellular flagellates, while others gather in groups. Pinctada, a kind of green algae, is made up of countless branched filaments, and the morphology and function of filaments in different parts are also different.

Although algae are mainly aquatic, they are everywhere, from temperate forests to polar plains. Some varieties can live in soil and tolerate long-term water shortage conditions; Others live in the snow; Some species can thrive in hot springs.

Living habits of algae:

Algae are mostly aquatic, with algae; Freshwater algae are also born in land water. Among aquatic algae, there are phytoplankton with increased body surface area (such as single cell, colony, flat, angular or spiny, etc. ), substances with small specific gravity stored in the body, or flagella adapted to floating life.

There are benthic algae covered with colloid, and there are fixators or rhizomes at the base, which grow on underwater substrates; There are also ice and snow algae growing on glaciers and snow; There are also hot spring algae living in hot springs with water temperature as high as 80℃ or above. There are still many algae whose algae bodies are not completely submerged in water, and some are aerial algae whose algae bodies are partially or completely exposed to the atmosphere.

Some are soil algae that grow on or below the soil surface. As far as the relationship between algae and other organisms is concerned, epiphytic algae are attached to the surfaces of animals and plants. There are also endophytic algae that grow in animals or plants.

There are * * * algae living with other creatures. In a word, the life habits of algae are varied and have strong adaptability to the environment, and algae are almost everywhere.