If you ever visit the beach you’d find these slimy plants on the beach, do you know what are they? They’re sea-weed. They’re nothing but Algae. So, what’re algae? Let us find out!
What are Algae?
Algae are organisms, or living things, that are spread all over the world. They grow in many different shapes, sizes, and colors. They can exist on their own or they can grow on the surfaces of other organisms, in the soil or on rocks. These organisms are very important because they make much of Earth’s oxygen, which humans and other animals need to breathe. Some of these organisms, such as seaweed, look like plants. However, they are actually neither plants nor animals. Instead, they belong to a group of living things called protists.
They vary greatly in size and grow in many diverse habitats. Microscopic algae, called phytoplankton, float or swim in lakes and oceans. Phytoplankton is so small that 1000 individuals could fit on the head of a pin. The largest forms of algae are seaweeds and can stretch up to 100m (300 ft) from the ocean bottom to the water’s surface.
Although most of these organisms grow in freshwater or seawater, they also grow on soil, trees, and animals such as turtles and polar bears and even under or inside porous rocks, such as sandstone and limestone. They can tolerate a wide range of temperatures and they can grow in hot springs, on snow banks, or deep within the polar ice.
The algae (singular alga) comprise several different groups of living organisms. They are usually found in wet places or water bodies and that capture light energy through photosynthesis, converting inorganic substances into simple sugars with the captured energy.
Nearly all algae have parts that do photosynthesis. They make oxygen, unlike other photosynthetic bacteria such as purple and green bacteria. Some unicellular algae rely entirely on external energy sources and have reduced or lost their photosynthetic apparatus.
The various sorts of algae play significant roles in aquatic ecology:
- Microscopic forms that live suspended in the water column, called phytoplankton, provide the food base for most marine food chains. In very high densities (so-called algal blooms) they may discolor the water and outcompete or poison other life forms.
- The seaweeds grow mostly in shallow marine waters; some are used as human food or are harvested for useful substances such as agar or fertilizer.
- Algae are the most important photosynthesizing organisms on Earth. They capture more of the sun’s energy and produce more oxygen than all plants combined.
- They form the foundation of most aquatic food webs, which support an abundance of animals.
- These organisms also form mutually beneficial partnerships with other organisms. For example, algae live with fungi to form lichens- plant like or branching growths that form on boulders, cliffs and tree trunks. Algae called zooxanthellae live inside the cells of reef-building coral. In both the cases, the algae provide oxygen and complex nutrients to their partner, and in return, they receive protection and simple nutrients. This arrangement enables both partners to survive in conditions that they could not endure alone.
- Algae have been used for centuries, especially in Asian countries, for their purported powers to cure or prevent illness as varied as a cough, gout, gallstones, goitre, hypertension, and diarrhoea. Recently, algae have been surveyed for anticancer compounds, with several cyan bacteria appearing to contain promising candidates. Diatoms also have been used in forensic medicine, as their presence in the lungs can indicate a person died due to drowning.
Question For You
Q. Which of the following microorganism is autotrophic in nature?
a. Algae b. Bacteria
c. Fungi d. None of the above
Ans: a. Algae
An organism that is capable of synthesizing its own food from inorganic substances using light or chemical energy is called as an autotrophic organism. It includes green plants, algae and certain bacteria. Algae are photoautotrophs meanings they use light as the source of energy to prepare their food.