Algae are a plural form of alga, an extensive group of myriad organisms that produces food through photosynthesis. They are different from a plant and have specific classifications and cell arrangements closely related to one another. Some of them are large, whereas others are multicellular.

However, the similarities are because of parallel evolution, where you will find that various organisms adapt similarly in similar niches. They are often described as polyphyletic, meaning their predecessors are different.

Here are some of the Algae products we offer.

What are algae, how we would define them, how many types there are, and are they good or bad?

Definition of algae:

It goes like this if you search for a modernized definition, their DNA is held in a nucleus, usually encircled by a membrane, and is known as eukaryotes. Others that fall in this category are plants, animals, and fungi. On the other hand, prokaryotes are referred to as archaea and bacteria. These microorganisms have major groups that depend on the pigments they use during photosynthesis. 

Types of algae:

  1. Green 
  2. Red
  3. Brown
  4. Cyanobacteria 
  5. Algal blooms 

Are Algae Good or Bad?

Whether it is the algae or the cyanobacteria, they are neither good nor bad for the aquatic environment. Instead, these organisms help produce oxygen which is necessary to sustain life. But, you must also note that if they take over, that is, if they are in large numbers, then the toxin that they release will cause harm to the animals, environment, and humans. However, you will also notice that seaweed is a photosynthetic plant but dissimilar in many habits.

Characteristics of Algae


From the basics, their primary characteristics are aquatic and photoautotrophic eukaryotes or aquatic organisms. Every algae and plant makes food from photosynthesis and has a more superficial anatomy compared to phototrophic eukaryotes. 

Nonetheless, their body project ranges from single-celled to colonial to multicellular. Some are non-motile, while others are motile (flogged). However, the maximum species are unicellular. 

Others live unassisted, while others form colonies or filaments. Multicellular forms have a reasonably complex structure systematized into parts serving different functions. 

However, the body regions are organ-like, with no specialization into true leaves, branches, and sources, as seen in bryophytes and tracheophytes. However, they have a cell wall primarily composed of cellulose. Additionally, their cell contains pectin, which renders messy algae.


Since you know they are phototropic, you will learn and recognize the others, such as heterotrophic and mixotrophic.

  • Phototropic means those that rely on the energy derived from photosynthesis. 
  • Heterotrophic are those that lose their pigment and get their food from other animals or anything alive.
  • Mixotrophic algae are those who receive energy from organic carbon uptake as well as photosynthesis.

Some examples are phagotraphy, osmotrophy, and mixotrophy.


The procedures of reproduction are different. Some reproduced sexually, whereas others asexually. 

When you look at the various algal classes, such as red and green, they have both processes in the cycle of their life. So, the asexual stage is when the organism is in a diploid state. In contrast, the sexual stage is when it is in a haploid situation. Hence, there are two haploid organisms that fuse to form a diploid zygote.


Algae can be seen in a spectrum of habitats ranging from marine and freshwater environments to moist soil and even in extreme conditions such as hot springs. Freshwater algae are widespread on land and influence oxygen in earth’s atmosphere. They are also known as aquatic life and often grow on rocks or other surfaces. Two aspects impact the abundance, and that are nutrients and light.

So nutrients are responsible for the algae that live in water. You must have heard of algal blooms or red tides, which happen because of their population explosion.  

Examples Of Algae Viewed Under A Microscope

Microscopic algae include diatoms, euglena, Chlamydomonas, and spirogyra.

  1. Diatoms are single-celled organisms with complex cell walls made of silica.
  2. Euglena is a green protist with both plant and animal characteristics.
  3. Chlamydomonas is a unicellular organism that has two flagella for movement.
  4. Spirogyra is filamentous with a spiral chloroplast that can be seen under a microscope.

All these examples are fascinating to observe and study under a microscope. They provide insight into some of the primary life forms on Earth and how they interact with their environment.

Examples of algae in the environment

1. Seaweed

Seaweed is found in oceans, seas, and other bodies of saltwater. It provides an important food source for many marine organisms, including fish and invertebrates. Seaweeds are an important part of saltwater as it helps create a balance.

2. Cyanobacteria

Cyanobacteria are another kind living in freshwater territories such as ponds, lakes, and rivers. You can also find it in soil and on the surfaces of rocks. Cyanobacteria are known to produce oxygen through photosynthesis, which is essential for life on Earth.

3. Phytoplankton

Phytoplankton is a tiny alga that floats near the water’s surface in oceans, seas, and other bodies of saltwater. They are significant oxygen producers through photosynthesis, providing a food source for many marine organisms.

4. Algae blooms

Algae blooms are large populations found in fresh and saltwater environments. They can cause significant environmental problems as they can deplete oxygen levels in the water, making it difficult for other organisms to survive. They also contribute to eutrophication, which is when high nutrient levels cause an increase in algae growth.

5. Marine

These are single-celled algae near the ocean’s surface. They have a silica shell and are important primary producers, providing food for fish and other organisms. They also play an essential role in the global carbon cycle by absorbing carbon dioxide from the atmosphere.

6. Microscopic algae

A wide variety of microscopic alga, such as dinoflagellates, and green algae, can be found in virtually every aquatic environment. Although small, these organisms play an important role as primary producers, providing food for other marine organisms.

7. Pond scum

Pond scum is also a type of algae that creates a thick layer on the surface of ponds and lakes. It comprises various species, such as filamentous, green, and blue-green algae. These organisms contribute to eutrophication by using oxygen and nutrients in the water, making it difficult for other organisms to survive.

8. Algae on rocks

Certain algae, such as lichens and cyanobacteria, grow on the surface of stones in freshwater and saltwater environments. They are essential for keeping the rocks clean and providing food for other marine organisms.

9. Algae in soil

It is also found in soil and on the surfaces of plants. They play a crucial role in maintaining the health of the ground by providing nutrients for plants and other organisms. It also helps control erosion by stabilizing soils with their root-like structures.

10. Algae on snow

Certain algae can grow on snow’s surface in cold climates. These organisms provide a food source for other organisms in the environment and help regulate soil temperatures by absorbing sunlight.

Relationship to Land Plants

Algae are supposed to be the ancestors of all land plants. Algae and their descendants share similar characteristics, such as cell walls composed of cellulose, photosynthesis for energy production, and in some species, the presence of vascular tissue (xylem and phloem). 

In addition, they possess similarities at the molecular level; and share similar peptides, transcriptional regulators, and protein-protein interactions, which suggest an evolutionary relationship. Furthermore, genetic studies have revealed that the biological processes involved in developing are very similar to those found in algae.

In short, it is widely accepted that they evolved from a group of primitives over millions of years of evolution. 

Though this ancestral algae’s exact form is unknown, it is likely to have been a single-celled organism that had already acquired some traits associated with modern land plants. By studying the similarities between these two distinct groups, scientists can better understand how life on Earth has evolved.

Algae are also food for aquatic and usually live in colonies. So, whether it is running water or stagnant water body, they thrive in freshwater. Plus the presence of green pigment chlorophyll and energy from the sun allows them to make food and the process is known as photosynthesis. This is mostly common in green algal species.


Algal groups

The system of classification is done on the pigments they use for photosynthesis. They are also known as photosynthetic organisms. This is specifically for red, green, golden, and brown algae. However, green and blue colors are Cyanophyta and counted as bacteria rather than including them in this kingdom. 

What Organelles Do Algae Contain?

Algae contain a variety of organelles, which are all critical for their functioning. Some of the most common organelles include chloroplasts, mitochondria, peroxisomes, endoplasmic reticulum (ER), Golgi apparatus, and vacuoles.

  • Chloroplasts help to capture light energy for photosynthesis, the process by which light energy is converted into chemical energy.
  • Mitochondria produce energy for cellular activities in the form of ATP molecules.
  • Peroxisomes help to break down and metabolize organic compounds.
  • The ER acts as a transport network within the cell, delivering proteins from one organelle to another.
  • The Golgi apparatus helps package and send proteins and other molecules outside the cell.
  • Vacuoles are membrane-bound organelles that store nutrients, enzymes, or toxins.

These different organelles work together to allow algae to survive and thrive in its environment.

Why Are Algae Important?

Algae are necessary for a variety of reasons. They serve as an essential source of food and oxygen in aquatic ecosystems, acting as the primary producer at the base of the food web. 

It is considered a valuable part of many marine-based industries, such as aquaculture, medical research, wastewater treatment, bioremediation, and fuel production. It provides an indispensable source of nutrients for other organisms and helps to maintain a balanced ecosystem. 

In addition, they are known to produce a wide range of bioactive compounds that are beneficial for human health, such as vitamins, anti-inflammatory agents, antioxidants, and anti-microbial substances. 

Finally, certain species, such as biofertilizers or bioplastics, are helpful for agricultural and industrial purposes. Therefore, it is an essential part of our environment and plays an integral role in sustaining the well-being of our planet. 

Green algae

When a photosynthetic alga is characterized by pigments such as chlorophyll a and chlorophyll b is known as green algae. They are famous for storing food in the form of starch within the plastids. Therefore their diverse forms are:-


Unicellular are those that comprise both kinds of algae. Some examples are Euglenophyta and flagellated, which are encountered in freshwater.


It refers to the form that looks filamentous, or they form leaf-like thallus. An example is Ulva sp.


The species that form colonies are Volvox sp, the green algae that contain charophytes, primarily available in freshwater habitats. The other green in color lives in terrestrial habitats such as trees, soil, and rocks. They usually form a symbiosis, for example, hydra sp or chlorella sp.

Red algae

Those that belong to the Rhodophyta species are known as red algae. They are identified because of red color pigmentation.

The presence of phycoerythrin, phycocyanin, and allophycocyanins in phycobilisomes, other than chlorophyll, is liable for its coloration. However, some examples are Rhodella, Compsopogon, stylonema, Bangia, Porphyra, Porphyridium cruentum, etc.

Brown algae

The presence of fucoxanthin and chlorophyll gives them a brown tint, popularly known as brown algae. It comes with the phylum Phaeophyta. Apart from Phaeophyta, other species with prevailing brown stains other than chlorophyll are olive-brown Bacillariophyta, and Dinoflagellata (dinoflagellates).

Golden algae

Algae that is golden in hue falls under the category of phylum Chrysophyceae. However, a widespread alga is Prymnesium parvum, which is associated with fish killing. 

Blue-green algae

Blue or green species of algae are included in the members of the Cyanophyta. Other references do not consider them as they are prokaryotes. Also, they have similarities to algal species, such as being photosynthetic because it has chlorophyll in them. Besides this pigment, the blue-green algal cell also has phycobiliproteins that give them this color (thus, the name).